Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2017	Mar. 12, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Trading Symbol	BNFT
Entity Registrant Name	Benefitfocus,Inc.
Entity Central Index Key	0001576169
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		31,331,447
Entity Public Float			$ 426,784,296

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 55,335	$ 56,853
Marketable securities	0	2,007
Accounts receivable, net	30,156	28,340
Accounts receivable, related party, net	0	4,626
Prepaid expenses and other current assets	4,337	4,449
Total current assets	89,828	96,275
Property and equipment, net	72,681	80,518
Intangible assets, net	150	408
Goodwill	1,634	1,634
Other non-current assets	816	1,575
Total assets	165,109	180,410
Current liabilities:
Accounts payable	4,260	5,829
Accrued expenses	9,136	10,867
Accrued compensation and benefits	14,250	17,347
Deferred revenue, current portion	38,821	35,426
Revolving line of credit, current portion	24,000	20,000
Financing and capital lease obligations, current portion	3,423	2,604
Total current liabilities	93,890	92,073
Deferred revenue, net of current portion	19,898	40,412
Revolving line of credit, net of current portion	32,246	20,246
Financing and capital lease obligations, net of current portion	55,597	57,934
Other non-current liabilities	2,809	3,056
Total liabilities	204,440	213,721
Commitments and contingencies	0	0
Stockholders' deficit:
Preferred stock, par value $0.001, 5,000,000 shares authorized, no shares issued and outstanding at December 31, 2017 and 2016	0	0
Common stock, par value $0.001, 50,000,000 shares authorized, 31,307,989 and 30,429,014 shares issued and outstanding at December 31, 2017 and 2016, respectively	31	30
Additional paid-in capital	355,301	335,059
Accumulated deficit	(394,663)	(368,400)
Total stockholders' deficit	(39,331)	(33,311)
Total liabilities and stockholders' deficit	$ 165,109	$ 180,410

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	31,307,989	30,429,014
Common stock, shares outstanding	31,307,989	30,429,014

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenue	$ 256,735	$ 233,335	$ 185,143
Cost of revenue	124,156	120,681	102,851
Gross profit	132,579	112,654	82,292
Operating expenses:
Sales and marketing	69,280	55,488	58,589
Research and development	49,549	56,584	52,250
General and administrative	27,268	32,750	25,727
Total operating expenses	146,097	144,822	136,566
Loss from operations	(13,518)	(32,168)	(54,274)
Other income (expense):
Interest income	182	138	188
Interest expense on building lease financing obligations	(7,450)	(6,826)	(7,092)
Interest expense on other borrowings	(4,931)	(1,095)	(877)
Other expense	(140)	(90)	(4)
Total other expense, net	(12,339)	(7,873)	(7,785)
Loss before income taxes	(25,857)	(40,041)	(62,059)
Income tax expense	15	17	25
Net loss	(25,872)	(40,058)	(62,084)
Comprehensive loss	$ (25,872)	$ (40,058)	$ (62,084)
Net loss per common share:
Basic and diluted	$ (0.83)	$ (1.35)	$ (2.19)
Weighted-average common shares outstanding:
Basic and diluted	31,052,378	29,589,857	28,344,680

Consolidated Statements of Changes in Stockholders' Deficit - USD ($) $ in Thousands	Total	Common Stock, $0.001 Par Value	Additional Paid-in Capital	Accumulated Deficit
Balance at Dec. 31, 2014	$ (42,823)	$ 26	$ 223,409	$ (266,258)
Balance (in shares) at Dec. 31, 2014		25,608,937
Exercise of stock options	4,229	$ 0	4,229	0
Exercise of stock options (in shares)		656,043
Issuance of common stock upon vesting of restricted stock units, net of shares surrendered for taxes	(2,116)	$ 0	(2,116)	0
Issuance of common stock upon vesting of restricted stock units, net of shares surrendered for taxes (in shares)		111,826
Issuance of common stock for cashless exercise of warrant	74,331	$ 3	74,328	0
Issuance of common stock for cashless exercise of warrant (in shares)		2,817,526
Stock-based compensation expense	10,454	$ 0	10,454	0
Net loss	(62,084)	0	0	(62,084)
Balance at Dec. 31, 2015	(18,009)	$ 29	310,304	(328,342)
Balance (in shares) at Dec. 31, 2015		29,194,332
Exercise of stock options	6,870	$ 1	6,869	0
Exercise of stock options (in shares)		944,706
Issuance of common stock upon vesting of restricted stock units, net of shares surrendered for taxes	(202)	$ 0	(202)	0
Issuance of common stock upon vesting of restricted stock units, net of shares surrendered for taxes (in shares)		289,976
Stock-based compensation expense	18,088	$ 0	18,088	0
Net loss	(40,058)	0	0	(40,058)
Balance at Dec. 31, 2016	$ (33,311)	$ 30	335,059	(368,400)
Balance (in shares) at Dec. 31, 2016	30,429,014	30,429,014
Cumulative effect adjustment from adoption of new accounting standard \| Accounting Standards Update 2016-09	$ 0	$ 0	391	(391)
Exercise of stock options	$ 3,458	$ 1	3,457	0
Exercise of stock options (in shares)	463,870	463,870
Issuance of common stock upon vesting of restricted stock units	$ 0	$ 0	0	0
Issuance of common stock upon vesting of restricted stock units (in shares)		406,936
Issuance of common stock under Employee Stock Purchase Plan, or ESPP	257	$ 0	257	0
Issuance of common stock under Employee Stock Purchase Plan, or ESPP (in shares)		8,169
Stock-based compensation expense	16,137	$ 0	16,137	0
Net loss	(25,872)	0	0	(25,872)
Balance at Dec. 31, 2017	$ (39,331)	$ 31	$ 355,301	$ (394,663)
Balance (in shares) at Dec. 31, 2017	31,307,989	31,307,989

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities
Net loss	$ (25,872)	$ (40,058)	$ (62,084)
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Depreciation and amortization	15,906	13,073	11,664
Stock-based compensation expense	16,137	18,088	10,454
Interest accrual on financing obligations	7,500	6,827	7,092
Provision for doubtful accounts	75	667	22
Loss on disposal or impairment of property and equipment	157	141	18
Changes in operating assets and liabilities:
Accounts receivable, net	2,735	(3,936)	(7,800)
Accrued interest on short-term investments	7	220	205
Prepaid expenses and other current assets	112	1,626	(1,328)
Other non-current assets	759	339	1,380
Accounts payable	(1,372)	(1,849)	3,418
Accrued expenses	(1,617)	990	2,961
Accrued compensation and benefits	(3,097)	(3,337)	3,310
Deferred revenue	(17,119)	(17,690)	(1,189)
Other non-current liabilities	(248)	2,073	332
Net cash and cash equivalents used in operating activities	(5,937)	(22,826)	(31,545)
Cash flows from investing activities
Purchases of short-term investments held to maturity	0	(2,004)	(68,185)
Proceeds from short-term investments held to maturity	2,000	40,225	32,667
Purchases of property and equipment	(8,279)	(12,705)	(14,727)
Net cash and cash equivalents (used in) provided by investing activities	(6,279)	25,516	(50,245)
Cash flows from financing activities
Draws on revolving line of credit	105,000	84,000	57,492
Payments on revolving line of credit	(89,000)	(74,000)	(44,903)
Proceeds from exercises of stock options and ESPP	3,715	6,870	4,229
Proceeds from issuance of common stock and warrant, net of issuance costs	0	0	74,538
Payments of deferred financing costs and debt issuance costs	0	(379)	(566)
Remittance of taxes upon vesting of restricted stock units	0	(202)	(2,116)
Payments on financing and capital lease obligations	(9,017)	(10,200)	(9,884)
Net cash and cash equivalents provided by financing activities	10,698	6,089	78,790
Net (decrease) increase in cash and cash equivalents	(1,518)	8,779	(3,000)
Cash and cash equivalents, beginning of year	56,853	48,074	51,074
Cash and cash equivalents, end of year	55,335	56,853	48,074
Supplemental disclosure of non-cash investing and financing activities
Property and equipment purchases in accounts payable and accrued expenses	389	699	1,489
Property and equipment purchased with financing and capital lease obligations	0	28,032	914
Post contract support purchased with financing obligations	0	1,048	272
Allocation of proceeds to deferred revenue from issuance of common stock based on relative selling price	0	0	207
Supplemental disclosure of cash flow information
Income taxes paid	14	7	18
Interest paid	$ 10,911	$ 6,655	$ 6,525

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Principles of Consolidation

These consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company is not the primary beneficiary of, nor does it have a controlling financial interest in, any variable interest entity. Accordingly, the Company has not consolidated any variable interest entity.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Such estimates include revenue recognition and the customer relationship period, allowances for doubtful accounts and returns, valuations of deferred income taxes, long-lived assets, warrants, capitalizable software development costs and the related amortization, stock-based compensation, the determination of the useful lives of assets, and the impairment assessment of acquired intangibles and goodwill. Determination of these transactions and account balances are based on the Company’s estimates and judgments. These estimates are based on the Company’s knowledge of current events and actions it may undertake in the future as well as on various other assumptions that it believes to be reasonable. Actual results could differ materially from these estimates.

Revenue and Deferred Revenue

The Company derives the majority of its revenue from software services fees, which consist primarily of monthly subscription fees paid by customers for access to and usage of the Company’s cloud-based benefits software solutions for a specified contract term. The Company also derives revenue from professional services which primarily include fees related to the integration of customers’ systems with the Company’s platform, which typically includes discovery, configuration, deployment, testing, and training.

The Company recognizes revenue when there is persuasive evidence of an arrangement, the service has been provided, the fees to be paid by the customer are fixed and determinable and collectability is reasonably assured. The Company considers delivery of its cloud-based software services has commenced once access to a configured and live instance to its platform has been granted to the customer.

The Company’s arrangements generally contain multiple elements comprised of software services and professional services. The Company evaluates each element in an arrangement to determine whether it represents a separate unit of accounting. An element constitutes a separate unit of accounting when the delivered item has standalone value and delivery of the undelivered element is probable and within the Company’s control.

When multiple deliverables included in an arrangement are separable into different units of accounting, the arrangement consideration is allocated to the identified units of accounting based on their relative selling price. Multiple deliverable arrangements accounting guidance provides a hierarchy to use when determining the relative selling price for each unit of accounting. Vendor-specific objective evidence (“VSOE”) of selling price, based on the price at which the item is regularly sold by the vendor on a standalone basis, should be used if it exists. If VSOE of selling price is not available, third-party evidence (“TPE”) of selling price is used to establish the selling price if it exists. VSOE and TPE do not currently exist for any of the Company’s deliverables. Accordingly, for arrangements with multiple deliverables that can be separated into different units of accounting, the arrangement consideration is allocated to the separate units of accounting based on the Company’s best estimate of selling price. The amount of arrangement consideration allocated is limited by contingent revenues, if any.

Effective July 1, 2015, the Company determined it had established standalone value for Benefitfocus Marketplace implementation services in the Employer segment as they can be sold separately from the software services. This was primarily due to the system integrators that have been trained and certified to perform these implementation services, the successful completion of an implementation by a trained system integrator, and the sale of several software subscription arrangements to customers in the Employer segment without the Company’s implementation services. Accordingly, revenues related to implementation services for the Benefitfocus Marketplace solution in the Employer segment that are delivered after July 1, 2015 are recognized separately from the revenues earned from the Employer software subscription services. Revenues related to such implementation services are recognized at the time that the professional services have been completed and the related software services have commenced. Prior to July 1, 2015, the Company did not have standalone value for implementation services related to the Benefitfocus Marketplace solution as the Company had historically performed these services to support customers’ implementation of this solution.

Certain of the Company’s other professional services, including implementation services related to the Carrier segment, are not sold separately from the software services and there is no alternative use for them. As such, the Company has determined that those professional services do not have standalone value. Accordingly, software services and professional services are combined and recognized as a single unit of accounting. The Company generally recognizes software services fees monthly based on the number of employees covered by the relevant benefits plans at contracted rates for a specified period of time, once the criteria for revenue recognition described above have been satisfied. With the exception of Benefitfocus Marketplace implementation services discussed above, the Company defers recognition of revenue for fees from professional services that do not have standalone value and begins recognizing such revenue once the services are delivered and the related software services have commenced, ratably over the longer of the contract term or the estimated expected life of the customer relationship. Costs incurred by the Company in connection with providing such professional services are charged to expense as incurred and are included in “Cost of revenue.”

Cost of Revenue

Cost of revenue primarily consists of employee compensation, professional services, data center co-location costs, networking expenses, depreciation expense for computer equipment directly associated with generating revenue, amortization expense for capitalized software development costs, and infrastructure maintenance costs. In addition, the Company allocates a portion of overhead, such as facilities and security costs, additional depreciation and amortization expense, and employee benefit costs, to cost of revenue based on headcount.

Cash and Cash Equivalents

Cash and cash equivalents consist of bank checking accounts and money market accounts. The Company considers all highly liquid investments with original maturities of three months or less at the time of purchase to be cash equivalents.

Marketable Securities

Marketable securities consist of short-term investments in corporate bonds, commercial paper, and various U.S. government backed securities. To reflect its intention, the Company classifies its marketable securities as held-to-maturity at the time of purchase. As a result, the marketable securities are recorded at amortized cost and any gains or losses realized upon maturity are reported in other expense, net in the consolidated statements of operations and comprehensive loss.

Concentrations of Credit Risk

The Company’s financial instruments that are exposed to concentrations of credit risk consist primarily of cash equivalents, marketable securities and accounts receivable. All of the Company’s cash and cash equivalents are held at financial institutions that management believes to be of high credit quality. The bank deposits of the Company might, at times, exceed federally insured limits and are generally uninsured and uncollateralized. The Company has not experienced any losses on cash and cash equivalents to date.

To manage credit risk related to marketable securities, the Company invests in various types of highly rated corporate bonds, commercial paper, and various U.S. government backed securities with maturities of less than two years. The weighted average maturity of the portfolio of investments must not exceed nine months, per the Company’s investment policy.

To manage accounts receivable risk, the Company evaluates the creditworthiness of its customers and maintains an allowance for doubtful accounts. Accounts receivable were unsecured and were derived from revenue earned from customers located in the United States. Accounts receivable from one customer represented approximately 12% and 14% of the total accounts receivable at December 31, 2017 and 2016, respectively, and approximately 12% and 11% of total revenue for the year ended December 31, 2017 and 2016, respectively. The revenue is attributable to the Company’s Employer segment. Another customer represented approximately 13% of the total accounts receivable at December 31, 2016.

No customer represented more than 10% of total revenue for the year ended December 31, 2015.

Accounts Receivable and Allowance for Doubtful Accounts and Returns

Accounts receivable are stated at realizable value, net of allowances for doubtful accounts and estimated returns. The Company utilizes the allowance method to provide for doubtful accounts based on management’s evaluation of the collectability of amounts due, and other relevant factors. Bad debt expense is recorded in general and administrative expense on the consolidated statements of operations and comprehensive loss. The Company’s estimate is based on historical collection experience and a review of the current status of accounts receivable. Historically, actual write-offs for uncollectible accounts have not significantly differed from the Company’s estimates. The Company removes recorded receivables and the associated allowances when they are deemed permanently uncollectible. However, higher than expected bad debts may result in future write-offs that are greater than the Company’s estimates. The allowance for doubtful accounts was $654 and $691 as of December 31, 2017 and 2016, respectively.

The allowances for returns are accounted for as reductions of revenue and are estimated based on the Company’s periodic assessment of historical experience and trends. The Company considers factors such as the time lag since the initiation of revenue recognition, historical reasons for adjustments, new customer volume, delivery issues or delays, and past due customer billings. The allowance for returns was $2,812 and $3,904 as of December 31, 2017 and 2016, respectively.

Property and Equipment and Capitalized Software Development Costs

Property and equipment, including capitalized software development costs, are stated at cost less accumulated depreciation and amortization. Expenditures for major additions and improvements are capitalized. Depreciation and amortization is recognized over the estimated useful lives of the related assets using the straight-line method.

The estimated useful lives for significant property and equipment categories are generally as follows:

Buildings		30 years
Computers and related equipment		3-5 years
Purchased software and licenses		1-7 years
Developed software		3 years
Furniture and fixtures		7 years
Leasehold improvements		Lesser of estimated useful life of asset or lease term
Other equipment		5-12 years
Vehicles		5 years

Useful lives of significant assets are periodically reviewed and adjusted prospectively to reflect the Company’s current estimates of the respective assets’ expected utility. Costs associated with maintenance and repairs are expensed as incurred.

The Company capitalizes certain costs related to its software developed or obtained for internal use. Costs related to preliminary project activities and post-implementation activities are expensed as incurred. Internal and external costs incurred during the application development stage, including upgrades and enhancements representing modifications that will result in significant additional functionality, are capitalized. Software maintenance and training costs are expensed as incurred. Capitalized costs are recorded as part of property and equipment and are amortized on a straight-line basis over the software’s estimated useful life which is three years. The Company evaluates these assets for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets.

Identifiable Intangible Assets

Identifiable intangible assets with finite lives are recorded at their fair values at the date of acquisition and are amortized on a straight-line basis over their respective estimated useful lives, which is the period over which the asset is expected to contribute directly or indirectly to future cash flows. As of December 31, 2017, the estimated remaining useful life used in computing amortization was 0.6 years.

Impairment of Long-Lived Assets and Goodwill

The Company reviews long-lived assets and definite-lived intangible assets for impairment whenever events or changes in circumstances indicate the carrying amount of an asset might not be recoverable. Recoverability of the long-lived asset is measured by a comparison of the carrying amount of the asset or asset group to future undiscounted net cash flows expected to be generated. If such assets are not recoverable, the impairment to be recognized, if any, is measured as the amount by which the carrying amount of the assets exceeds the estimated fair value (discounted cash flow) of the assets or asset group. Assets held for sale are reported at the lower of the carrying amount or fair value, less costs to sell.

Goodwill represents the excess of the aggregate of the fair value of consideration transferred in a business combination over the fair value of assets acquired, net of liabilities assumed. Goodwill is not amortized; rather, goodwill is tested for impairment at the reporting unit level as of October 31 of each year, or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value.

The Company performs a qualitative assessment to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value before performing a two-step approach to testing goodwill for impairment for each reporting unit. The reporting units are determined by the components of the Company’s operating segments that constitute a business for which both (1) discrete financial information is available and (2) segment management regularly reviews the operating results of that component. If it is more likely than not that the fair value of a reporting unit is less than its carrying value, the Company performs the impairment test by applying a fair-value-based test. The first step measures for impairment by applying fair-value-based tests at the reporting unit level. The second step (if necessary) measures the amount of impairment by applying fair-value-based tests to the individual assets and liabilities within each reporting unit.

The Company has identified two reporting units, Employer and Carrier. To determine the fair value of the Company’s reporting units, the Company has used a discounted cash flow analysis, which requires significant assumptions and estimates about future operations. Significant judgments inherent in this analysis include the determination of an appropriate discount rate, estimated terminal value and the amount and timing of expected future cash flows. The Company may also determine fair value of its reporting units using a market approach by applying multiples of earnings of peer companies to its operating results.

Financing Obligations

In its build-to-suit lease arrangements where the Company is involved in the construction of its buildings, the Company is deemed the owner for accounting purposes during the construction period. The Company records an asset for the amount of the total project costs in Property and Equipment, net and the related financing obligation in Financing and Capital Lease Obligations on the Consolidated Balance Sheet. Once construction is complete, the Company determines if the asset qualifies for sale-leaseback accounting treatment. If the arrangement does not qualify for sale-lease back treatment, the Company continues to reduce the obligation over the lease term as payments are made and depreciates the asset over its useful life. The Company does not report rent expense for the portion of the rent payment determined to be related to the assets that it owns for accounting purposes. Rather, this portion of the rent payment under the lease is recognized as a reduction of the financing obligation and as interest expense.

Financing obligations also include liabilities for the purchase of software licenses.

Sales Commissions

Sales commissions are generally expensed when the sales contract is executed by the customer.

Advertising

The Company expenses advertising costs as they are incurred. Direct advertising costs for the years ended December 31, 2017, 2016, and 2015 were $168, $635 and $435, respectively.

Comprehensive Loss

The Company’s net loss equals comprehensive loss for all periods presented.

Stock-Based Employee Compensation

Stock-based employee compensation is measured based on the grant-date fair value of the awards and recognized in the Consolidated Statements of Operations and Comprehensive Loss over the period during which the award holder is required to perform services in exchange for the award, which is the vesting period. Compensation expense is recognized over the vesting period of the applicable award using the straight-line method. Compensation expense related to performance-based restricted stock units, which are accounted for as equity awards, is recognized when it is probable that the performance measure will be met. Compensation costs related to restricted stock units (“RSUs”) is based on the market price on the grant date. The Company uses the Black-Scholes option pricing model for estimating the fair value of stock options. The use of the option valuation model requires the input of subjective assumptions, including the expected life of the option and the expected stock price volatility. Additionally, prior to January 1, 2017, the recognition of stock-based compensation expense required the estimation of the number of options and RSUs that will ultimately vest and the number of options and RSUs that will ultimately be forfeited. Starting January 1, 2017, the Company recognizes the effect of forfeitures as they occur. The recognition of stock-based compensation expense associated with performance-based restricted stock units requires the estimation of the probability of achieving performance measures.

The Company adopted the guidance in Accounting Standards Update ("ASU") 2016-09, “Compensation - Stock Compensation (Topic 718) - Improvements to Employee Share-Based Payment Accounting,” on January 1, 2017. Under this ASU, entities are permitted to make an accounting policy election to either estimate forfeitures on share-based payment awards, as previously required, or to recognize forfeitures as they occur. The Company has elected to recognize forfeitures as they occur and the impact of that change in accounting policy has been recorded as a $391 cumulative effect adjustment to its accumulated deficit as of January 1, 2017.

Income Taxes

The Company uses the asset and liability method for income tax accounting. This method requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial reporting and tax basis of assets and liabilities, as well as for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using the tax rates that are expected to apply to taxable income for the years in which those tax assets and liabilities are expected to be realized or settled. Valuation allowances are recorded to reduce deferred tax assets to the amount the Company believes is more likely than not to be realized. The tax benefits of uncertain tax positions are recognized only when the Company believes it is more likely than not that the tax position will be upheld on examination by the taxing authorities based on the merits of the position. The Company recognizes interest and penalties, if any, related to unrecognized income tax benefits in income tax expense.

In addition to the compensation expense provisions previously discussed, ASU 2016-09 requires that all income tax effects related to settlements of share-based payment awards be reported in earnings as an increase or decrease to income tax expense (benefit), net. Previously, income tax benefits at settlement of an award were reported as an increase (or decrease) to additional paid-in capital to the extent that those benefits were greater than (or less than) the income tax benefits reported in earnings during the award's vesting period. The requirement to report those income tax effects in earnings has been applied on a prospective basis to settlements occurring on or after January 1, 2017 and the impact of applying that guidance was not material to the consolidated financial statements for the year ended December 31, 2017.

ASU 2016-09 also requires that all income tax-related cash flows resulting from share-based payments be reported as operating activities in the statement of cash flows. Previously, income tax benefits at settlement of an award were reported as a reduction to operating cash flows and an increase to financing cash flows to the extent that those benefits exceeded the income tax benefits reported in earnings during the award's vesting period. The Company has elected to apply that change in cash flow classification on a prospective basis. However, there is no impact to the statement of cash flows for the year ended December 31, 2017, as the Company did not have any cash flows related to excess tax benefits during that time. The remaining provisions of ASU 2016-09 did not have a material impact on the accompanying consolidated financial statements.

Basic and Diluted Net Loss per Common Share

The Company uses the two-class method to compute net loss per common share because the Company has issued securities, other than common stock, that contractually entitle the holders to participate in dividends and earnings of the Company. The two-class method requires earnings for the period to be allocated between common stock and participating securities based upon their respective rights to receive distributed and undistributed earnings. Holders of each series of the Company’s redeemable convertible preferred stock were entitled to participate in distributions, when and if declared by the board of directors that are made to common stockholders, and as a result are considered participating securities.

Under the two-class method, for periods with net income, basic net income per common share is computed by dividing the net income attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Net income attributable to common stockholders is computed by subtracting from net income the portion of current year earnings that the participating securities would have been entitled to receive pursuant to their dividend rights had all of the year’s earnings been distributed. No such adjustment to earnings is made during periods with a net loss, as the holders of the participating securities have no obligation to fund losses. Diluted net loss per common share is computed under the two-class method by using the weighted-average number of shares of common stock outstanding plus, for periods with net income attributable to common stockholders, the potential dilutive effects of stock awards and warrants. In addition, the Company analyzes the potential dilutive effect of the outstanding participating securities under the “if-converted” method when calculating diluted earnings per share, in which it is assumed that the outstanding participating securities convert into common stock at the beginning of the period. The Company reports the more dilutive of the approaches (two-class or “if-converted”) as its diluted net income per share during the period. Due to net losses for the years ended December 31, 2017, 2016, and 2015 basic and diluted loss per share were the same, as the effect of potentially dilutive securities would have been anti-dilutive.

Recent Accounting Pronouncements

In January 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-04, "Simplifying the Test for Goodwill Impairment." It eliminates Step 2 from the goodwill impairment test and an entity should recognize an impairment charge for the amount by which the carrying amount of goodwill exceeds the reporting unit's fair value, not to exceed the carrying amount of goodwill. This guidance is effective for annual and any interim impairment tests starting January 1, 2020. The Company does not expect this guidance to have any impact on its consolidated financial statements.

In August 2016, the FASB issued ASU No. 2016-15, "Classification of Certain Cash Receipts and Cash Payments." It provides guidance on eight specific cash flow issues with the objective of reducing the existing diversity in practice in how they are classified in the statement of cash flows. This guidance is effective for interim and annual reporting periods starting January 1, 2018. The Company does not expect this guidance to have a material impact on its consolidated financial statements.

In June 2016, the FASB ASU No. 2016-13, “Measurement of Credit Losses on Financial Instruments.” The purpose of this ASU is to require a financial asset measured at amortized cost basis to be presented at the net amount expected to be collected. Credit losses relating to available-for-sale debt securities should be recorded through an allowance for credit losses. This ASU is effective for interim and annual reporting periods starting January 1, 2020. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” The amendments in this update require lessees, among other things, to recognize lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under previous authoritative guidance. This update also introduces new disclosure requirements for leasing arrangements. ASU 2016-02 will be effective for the Company beginning January 1, 2019, but early adoption is permitted. The Company is currently evaluating the impact of this update on the consolidated financial statements.

In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which amends the revenue recognition requirements in the FASB Accounting Standards Codification. Under the new standard, revenue is recognized when a customer obtains control of promised goods or services and is recognized in an amount that reflects the consideration that the entity expects to receive in exchange for those goods and services. In addition, the new standard requires disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The FASB has issued several amendments to the new standard, including clarification on accounting for licenses of intellectual property and identifying performance obligations.

The Company will adopt the new standard effective January 1, 2018 using the full retrospective transition method and recast each prior reporting period presented.

The more significant impacts of the new standard to the Company are currently expected to be as follows:

•

The Company currently recognizes revenue from certain professional services in the Carrier segment over time, which is the customer relationship period. Under the new standard, revenue from certain of these services will be recognized over the contract term of the associated software services contract, including any extension periods representing a material right, or in some cases over the period of delivery of the professional fees, both of which are typically shorter than the customer relationship period.

•

The Company currently recognizes insurance broker commission revenue over the policy period. Under the new standard, the revenue related to broker commissions will be recognized when the orders for the policies are received and transferred to the insurance carrier. As a result, software services revenue from these arrangements in the Employer segment will be recognized earlier under the new standard in comparison to the current guidance.

•

The new standard provides guidance on accounting for certain revenue-related costs, including when to capitalize costs associated with obtaining and fulfilling a contract. The majority of these costs are currently expensed as incurred. Under the new standard, Carrier segment assets recognized for the costs to obtain a contract, which includes sales commissions, will be amortized on a systematic basis that is consistent with the transfer of the services to which the assets relate, considering anticipated renewals when applicable. Carrier segment assets recognized for costs to fulfill a contract, which include internal costs related to implementing carrier products, will be amortized on a systematic basis that is consistent with the transfer of the services to which the asset relates, which is generally expected to be five years. Costs to fulfill contracts in the Employer segment will be expensed as incurred.

The Company’s historical net cash flows provided by or used in operating, investing, and financing activities will not be impacted by adoption of the new revenue standard.

Net Loss Per Common Share

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Net Loss Per Common Share

3. Net Loss Per Common Share

Diluted loss per common share is the same as basic loss per common share for all periods presented because the effects of potentially dilutive items were anti-dilutive given the Company’s net loss. The following common share equivalent securities have been excluded from the calculation of weighted-average common shares outstanding because the effect is anti-dilutive for the periods presented:

	Year Ended December 31,
Anti-Dilutive Common Share Equivalents	2017		2016		2015
Restricted stock units		1,937,014		1,467,811		1,017,450
Stock options		263,155		727,559		1,684,843
Warrant to purchase common stock		-		580,813		580,813
Employee Stock Purchase Plan		7,039		3,964		-
Total anti-dilutive common share equivalents		2,207,208		2,780,147		3,283,106

Basic and diluted net loss per common share is calculated as follows:

	Year Ended December 31,
	2017			2016			2015
Numerator:
Net loss	$	(25,872	)	$	(40,058	)	$	(62,084	)
Net loss attributable to common stockholders	$	(25,872	)	$	(40,058	)	$	(62,084	)
Denominator:
Weighted-average common shares outstanding, basic and diluted		31,052,378			29,589,857			28,344,680
Net loss per common share, basic and diluted	$	(0.83	)	$	(1.35	)	$	(2.19	)

Marketable Securities

12 Months Ended

Dec. 31, 2017

Investments Debt And Equity Securities [Abstract]

Marketable Securities

4. Marketable Securities

Marketable securities consist of corporate bonds, commercial paper and U.S. Treasury and agency bonds, and are classified as held-to-maturity. Investments held in marketable securities had contractual maturities of less than one month as of December 31, 2016. As of December 31, 2017, the Company did not have any marketable securities. The following presents information about the Company’s marketable securities as of December 31:

	2016
Aggregate cost basis and net carrying amount	$	2,007
Gross unrealized holding gains		-
Gross unrealized holding losses		-
Aggregate fair value determined by Level 2 inputs	$	2,007

No investments were in an unrealized loss position as of December 31, 2016.

Fair Value Measurement

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Fair Value Measurement

5. Fair Value Measurement

The carrying amounts of certain of the Company’s financial instruments, including cash and cash equivalents, net accounts receivable, accounts payable and other accrued liabilities, and accrued compensation and benefits, approximate fair value due to their short-term nature. The carrying value of the Company’s financing obligations and revolving line of credit approximates fair value, considering the borrowing rates currently available to the Company for financing obligations with similar terms and credit risks.

The Company uses a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis, as well as assets and liabilities measured at fair value on a non-recurring basis, in periods subsequent to their initial measurement. The hierarchy requires the Company to use observable inputs when available, and to minimize the use of unobservable inputs when determining fair value. The three tiers are defined as follows:

Level 1. Quoted prices (unadjusted) in active markets for identical assets or liabilities.

Level 2. Other inputs that are directly or indirectly observable in the marketplace.

Level 3. Unobservable inputs for which there is little or no market data, which require the Company to develop its own assumptions.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The Company evaluates its financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level to classify them for each reporting period. This determination requires significant judgments to be made.

The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis using the above categories, as of December 31, 2017 and 2016.

	December 31, 2017
Description	Level 1		Level 2		Level 3		Total
Cash Equivalents:
Money market mutual funds ⁽¹⁾	$	46,730	$	-	$	-	$	46,730
Total assets	$	46,730	$	-	$	-	$	46,730

	December 31, 2016
Description	Level 1		Level 2		Level 3		Total
Cash Equivalents:
Money market mutual funds ⁽¹⁾	$	51,285	$	-	$	-	$	51,285
Total assets	$	51,285	$	-	$	-	$	51,285

(1)

Money market mutual funds are classified as cash equivalents in the Company’s consolidated balance sheets. As short-term, highly liquid investments readily convertible to known amounts of cash, with remaining maturities of three months or less at the time of purchase, the Company’s cash equivalent money market funds have carrying values that approximate fair value.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Property and Equipment

12 Months Ended

Dec. 31, 2017

Property Plant And Equipment [Abstract]

Property and Equipment

6. Property and Equipment

Property and equipment consists of the following as of December 31:

	2017			2016
Buildings, leased	$	48,558		$	48,558
Computers and related equipment		35,728			33,924
Purchased software and licenses		27,317			25,982
Developed software		30,624			26,142
Furniture and fixtures		6,669			6,668
Leasehold improvements		4,289			4,348
Other equipment		2,260			2,072
Vehicles		146			111
Construction in progress		-			319
Total property and equipment, at cost		155,591			148,124
Accumulated depreciation and amortization		(82,910	)		(67,606	)
Property and equipment, net	$	72,681		$	80,518

Depreciation and amortization expense on property and equipment was $15,648, $12,816 and $11,378, for the years ended December 31, 2017, 2016 and 2015, respectively. Property and equipment includes fixed assets acquired under capital lease agreements of $35,761 for both the years ended December 31, 2017 and 2016. Accumulated depreciation of assets under capital leases totaled $9,633 and $5,194 as of December 31, 2017 and 2016, respectively. Amortization of assets under capital leases is included in depreciation expense.

The Company capitalized software development costs of $4,482 and $5,242 for the years ended December 31, 2017 and 2016, respectively. Amortization of capitalized software development costs totaled $3,257, $2,857 and $2,587 during the years ended December 31, 2017, 2016 and 2015, respectively. The net book value of capitalized software development costs was $7,660 and $6,435 at December 31, 2017, and 2016, respectively.

Goodwill and Intangible Assets

12 Months Ended

Dec. 31, 2017

Goodwill And Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

7. Goodwill and Intangible Assets

The Company’s goodwill balance of $1,634 is solely attributable to the Employer reporting unit. The gross carrying amount and accumulated impairment losses were $3,304 and $(1,670), respectively, for the beginning and ending balances in all periods presented. There were no changes in the carrying amount of goodwill in the years ended December 31, 2017 and 2016.

Information regarding the Company’s acquisition-related intangible assets is as follows:

	As of December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted- Average Remaining Useful Life (in years)
Trademarks	$	240	$	(240	)	$	-		-
Customer agreements		2,060		(1,910	)		150		0.6
Non-compete agreements		126		(126	)		-		-
Total	$	2,426	$	(2,276	)	$	150		0.6

	As of December 31, 2016
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted- Average Remaining Useful Life (in years)
Trademarks	$	240	$	(240	)	$	-		-
Customer agreements		2,060		(1,652	)		408		1.6
Non-compete agreements		126		(126	)		-		-
Total	$	2,426	$	(2,018	)	$	408		1.6

Amortization expense of acquisition-related intangible assets for the years ended December 31, 2017, 2016 and 2015 was $258, $257 and $286, respectively. As of December 31, 2017, expected amortization expense for the intangible assets for the remaining useful life was $150, to be incurred during 2018. There were no impairments of intangible assets during the years ended December 31, 2017, 2016 and 2015.

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Revolving Line of Credit	12 Months Ended
Revolving Line of Credit	Dec. 31, 2017
Debt Disclosure [Abstract]
Revolving Line of Credit	8. Revolving Line of Credit On August 27, 2013, the Company executed a loan and security agreement with Silicon Valley Bank for a revolving line of credit (“Revolver”) in the initial amount of up to $15,000 for working capital, to fund general business requirements, and to repay the indebtedness under its then existing master credit facility and other senior secured promissory notes. At the beginning of 2014, the borrowing limit under the Revolver was increased from $15,000 to $35,000 at the request of the Company in accordance with the terms of the agreement, as amended on December 10, 2013. In February 2015, the Company replaced its Revolver with a senior revolving line of credit (“Senior Revolver”) with a syndicate of lenders led by Silicon Valley Bank. The Company borrowed $18,246 under the Senior Revolver, of which $17,657 repaid the principal of the Revolver and $589 paid accrued interest, as well as administrative and legal fees related to the issuance of the Senior Revolver. Debt issuance fees of $591 were capitalized in the Company’s balance sheet and are amortized over the life of the Senior Revolver. The Senior Revolver had an original borrowing limit of $60,000 and an original term of three years. Borrowing capacity under the Senior Revolver is subject to a borrowing base limit that is a function of the Company’s monthly recurring revenue as adjusted to reflect lost customer revenue during the previous three calendar months. Therefore, credit available under the Senior Revolver may be less than the borrowing limit. Interest is payable monthly. Advances under the Senior Revolver bear interest at the prime rate as published in the Wall Street Journal plus a margin based on the Company’s liquidity, which originally ranged between 1.0% and 1.5%. The Company is charged an unused line fee under this arrangement at a rate based on its liquidity, which was originally 0.300% to 0.375% per year. Any outstanding principal is due at the end of the term. In October and December 2016, the Company amended its Senior Revolver agreement. The October amendment, among other things, increased the borrowing capacity to $95,000, extended the termination date of the facility to February 20, 2020, and added Goldman Sachs Lending Partners LLC to the lending syndicate. The October amendment altered definitions in the Senior Revolver agreement, including Alternate Base Rate, Applicable Margin, Consolidated EBITDA, Liquidity and Commitment Fee Rate. As a result of certain of these definitional changes, the Alternate Base Rate was modified to be the prime rate as published in the Wall Street Journal plus a margin based on our liquidity that ranges between 0.75% and 1.25%. Certain covenants were also revised, including those related to accounts receivable, Minimum Consolidated EBITDA requirements, Indebtedness, permitted Indebtedness and certain capital expenditure limits. The October amendment further waived any default that may have occurred as a result of certain Indebtedness previously incurred by the Company and the disclosure to the lenders of registered Intellectual Property. In connection with the October amendment, debt issuance fees of $379 were capitalized in the Company’s balance sheet and are being amortized over the remaining life of the Senior Revolver. The December amendment revised the covenant restricting Indebtedness in the Senior Revolver agreement to increase the basket for the Company and its subsidiaries’ building lease obligations, to the extent those would be characterized as Indebtedness under the Senior Revolver agreement. In April 2017, the Company further amended its Senior Revolver agreement. The amendment altered definitions in the Credit Agreement, including Consolidated EBITDA and Liquidity, and changes the Minimum Liquidity and Minimum Consolidated EBITDA requirements. It also included consents by the lenders to certain administrative actions by the Company, including with respect to intellectual property and certain of its bank accounts. The amendment also modifies the definition of Excluded Assets in the Guarantee and Collateral Agreement, dated as of February 20, 2015, which was entered into in connection with the Senior Revolver. The Company is bound by customary affirmative and negative covenants in connection with the Senior Revolver agreement, including financial covenants related to liquidity and EBITDA. In the event of a default, the lenders may declare all obligations immediately due and stop advancing money or extending credit under the line of credit. The line of credit is collateralized by substantially all of the Company’s tangible and intangible assets, including intellectual property and the equity of subsidiaries. During 2017, 2016 and 2015, the Company borrowed an aggregate of $105,000, $84,000 and $39,246, respectively, under the Senior Revolver for general operating purposes and repaid an aggregate of $89,000, $74,000 and $27,246, respectively. As of December 31, 2017, the amount outstanding under the Senior Revolver was $56,246 and the amount available to borrow was $16,102. The amount outstanding, which represents principal and currently bears interest at 5.50%, is due February 2020. No other principal amounts are due in any other year.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2017

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

9. Commitments and Contingencies

The Company leases three buildings on its Charleston, South Carolina campus. One leasing arrangement is accounted for as a capital lease. The remaining two lease agreements are accounted for as build-to-suit, failed sale-leaseback arrangements. Accordingly, the Company recognized liabilities for the lease payments related to these two buildings, which have been recorded as financing obligations. A portion of the lease payment for these two leases has been allocated to land and is accounted for using operating lease accounting. Information regarding these three leases is incorporated in the following disclosures.

Operating Lease Commitments

The Company leases office facilities under various non-cancelable operating lease agreements with original lease periods expiring between 2018 and 2022. Some of the leases provide for renewal terms at the Company’s option. Certain future minimum lease payments due under these operating lease agreements contain free rent periods or escalating rent payment provisions. These leases generally do not contain purchase options. Rent expense on these operating leases is recognized over the term of the lease on a straight-line basis. Operating lease commitments include rent for land associated with the Company’s build-to-suit leases expiring through 2031.

In December 2016, the Company amended its three leases for buildings on its Charleston, South Carolina campus. As a result, one lease, that was previously accounted for as an operating lease was classified as a capital lease at the end of 2016.

Rent expense totaled $1,605, $4,403 and $4,376 for the years ended December 31, 2017, 2016 and 2015, respectively.

Future minimum lease payments are as follows:

	Operating Leases
Year Ending December 31,
2018	$	1,400
2019		1,429
2020		1,135
2021		1,101
2022		824
Thereafter		8,335
Total minimum lease payments	$	14,224

Financing and Capital Lease Obligations

The Company has entered into various purchase arrangements to obtain property and equipment for operations that are accounted for as capital leases. Certain purchase arrangements contain payments for licenses, which the Company records as financing obligations. These arrangements have original terms ranging from 2 to 5 years with interest rates ranging from 0.5% to 10.0%. The leases are secured by the underlying leased property and equipment.

In December 2016, the Company amended a lease agreement for office space that had been previously accounted for as an operating lease. The amendment extended the term of the lease by 15 years from the amendment date. This modification required the Company to evaluate the lease as if it were a new lease. Upon evaluation, the lease was classified as a capital lease because the present value of the lease payments exceeded 90% of the fair value of the leased asset. Aggregate payments under this lease are $48,600, including executory costs of $5,938. As of December 31, 2017, capital lease obligations include amounts under this lease of $20,571. Details of the lease extension are disclosed under “Contractual Commitments” below.

Financing obligations were $34,233 and $33,665, as of December 31, 2017 and 2016, respectively, and consist primarily of obligations for build-to-suit lease arrangements. The aggregate amount of future minimum payments for financing obligations was $110,367 at December 31, 2017 which includes aggregate payments of $108,659 related to build-to-suit arrangements. Details of the build-to-suit lease arrangements are disclosed in Note 15.

Financing obligations are allocated as follows:

	As of December 31,
	2017			2016
Buildings, build-to-suit	$	32,652		$	31,326
Software and support		1,581			2,339
Total financing obligations	$	34,233		$	33,665
Less: current portion		(1,283	)		(757	)
Financing obligations, net of current portion	$	32,950		$	32,908

Future minimum lease payments are as follows:

	Capital Leases			Financing Obligations
Year Ending December 31,
2018	$	5,089		$	7,759
2019		4,981			6,859
2020		3,216			6,747
2021		2,941			6,949
2022		3,029			7,158
Thereafter		31,697			74,895
Total minimum lease and financing obligation payments		50,953		$	110,367
Less: executory costs		(5,542	)
Less: imputed interest		(20,624	)
Less: current portion		(2,140	)
Capital lease obligations, net of current portion	$	22,647

Contractual Commitments

In connection with a 2013 lease for office space on its Charleston, South Carolina campus, the Company entered into an option to lease space in two additional adjacent buildings. The option term was 36 months and required the Company to incur costs annually prior to the exercise of the option in the amount of up to $466 per year. If the Company terminated the option or did not exercise the option prior to expiration it would incur termination fees pro-rated through the dates of termination or expiration. The maximum liability for termination fees was $757. During the year ended December 31, 2016, the Company determined that the options would expire unexercised and expensed the full amount of the termination fees.

On December 12, 2016, the Company executed an amendment to each of three lease agreements for office space on its Charleston, South Carolina campus. The amendments extended the term of the leases to December 31, 2031. The amendments also provided for the following:

•

extending from December 13, 2016 to December 31, 2018 the term of an option that allows the Company to require the lessors to build a two-story building, including potentially for a welcome center, of approximately 18,500 square feet on its campus (“Building 5”) for the Company to lease;

•

waiving accrued and future carrying costs and termination fees otherwise payable to the lessors by the Company under the existing option in the amount of $1,223; and

•

contingent upon construction of Building 4 described below, reducing the annual rent increases from 3% to 2% for the Company’s Customer Success Center, a 145,800 square foot building on its campus which it first occupied on January 1, 2015.

The waived carrying and termination fees in the amount of $1,223 is being amortized over the 15-year term of the extension as a reduction of interest and rent expense.

On December 12, 2016, the Company also executed a lease agreement pursuant to which the lessor will construct a building of approximately 145,800 square feet on its campus for the Company to accommodate anticipated future growth (“Building 4”). The target commencement date of the lease is July 1, 2019 with a term of 15 years. Under the terms of the lease, the Company agrees to commence construction on or about April 1, 2018, but can terminate the lease prior to that time, subject to the payment of reasonable, documented, and agreed-to out-of-pocket costs with respect to the lease and building to date. If the Company delays beginning construction past December 31, 2018, the lessor may terminate the lease. The Company may renew the lease upon 365 days’ notice to the lessor for five additional one-year terms, provided that the Company is not in default at the time of its request. Significant terms of the lease for Building 4 include annual rent for the first year of the lease of $30.05 per square foot of rentable area with annual rent increases of 2% of the rent paid for the preceding lease year. If the Company exercises its option to cause the construction of Building 5, the term of the lease will reset to 15 years from the date the Company begins paying rent for Building 5. The Company will begin to capitalize costs associated with the construction of Building 4 when construction has commenced.

The Company also has $6,570 of non-cancellable contractual commitments as of December 31, 2017 related to the purchase of software and maintenance. These commitments are not accrued in the consolidated balance sheet of the Company.

Legal Contingencies

The Company may become a party to a variety of legal proceedings that arise in the normal course of business. While the results of such normal course legal proceedings cannot be predicted with certainty, management believes, based on current knowledge, that the final outcome of any matters will not have a material adverse effect on the Company’s business, financial position, results of operations or cash flows.

Stock-based Compensation

12 Months Ended

Dec. 31, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-based Compensation

10. Stock-Based Compensation

Employee Stock-based Compensation Plan

The Company maintains the Amended and Restated Benefitfocus.com, Inc. 2000 Stock Option Plan (the “2000 Plan”) and the Benefitfocus.com, Inc. Amended and Restated 2012 Stock Plan, (the “2012 Plan”), pursuant to which the Company has reserved 4,832,623 shares of its common stock for issuance to its employees, directors and non-employee third parties. The 2012 Plan, effective on January 31, 2012, serves as the successor to the 2000 Plan and permits the granting of incentive stock options, non-statutory stock options, stock bonuses, stock purchase rights, stock appreciation rights, and restricted stock units and awards. No new awards can be issued under the 2000 Plan after the effective date of the 2012 Plan. Outstanding awards under the 2000 Plan continue to be subject to the terms and conditions of the 2000 Plan. Shares available for grant under the 2000 Plan, which were reserved but not issued or subject to outstanding awards under the 2000 Plan as of the effective date, were added to the reserves of the 2012 Plan. As of December 31, 2017, the Company had 2,632,454 shares allocated to the 2012 Plan, but not yet issued.

Stock options are granted at exercise prices not less than the estimated fair market value of the Company’s common stock at the date of grant. The grant date value of restricted stock units is equal to the closing price of the Company’s stock on the date of grant, or, if not a trading day, the closing price of the previous trading day. Generally, the Company issues previously unissued shares for the exercise of stock options or exchange of restricted stock units; however, previously acquired shares may be reissued to satisfy future issuances. The options and restricted stock unit awards typically vest over a four-year period. The options expire 10 years from the grant date. Compensation expense for the fair value of the stock-based awards at their grant date is recognized ratably over the vesting period.

The Company has issued two types of awards under these plans: stock options and restricted stock units. The following table sets forth the number of awards outstanding for each award type is as follows:

	Outstanding at December 31,
Award type	2017		2016		2015
Restricted stock units		1,937,014		1,467,811		1,017,450
Stock options		263,155		727,559		1,684,843

Compensation expense related to stock-based awards is included in the following line items in the accompanying consolidated statements of operations and comprehensive loss for the years ended December 31:

	2017		2016		2015
Cost of revenue	$	2,508	$	2,798	$	1,950
Sales and marketing		4,953		3,213		2,861
Research and development		2,990		4,532		2,399
General and administrative		5,686		7,545		3,244
	$	16,137	$	18,088	$	10,454

The total compensation cost related to non-vested awards not yet recognized as of December 31, 2017 was $31,608 and will be recognized over a weighted-average period of approximately 2.74 years.

Restricted Stock Units

During 2017, the Company granted restricted stock units under the 2012 Plan. Restricted stock units granted to employees vest in equal annual installments generally over 4 years from the grant date. The fair value of the stock at the time of grant is amortized based on a straight-line basis over the vesting period.

The summary of unvested restricted stock units is as follows:

	Restricted stock units			Weighted average grant date fair value
Unvested at December 31, 2016		1,467,811		$	34.33
Granted		1,142,253			28.90
Forfeited		(266,114	)		33.52
Vested		(406,936	)		35.23
Unvested at December 31, 2017		1,937,014		$	30.90

As of December 31, 2017, the number and intrinsic value of restricted stock units expected to vest was 1,471,818 and $39,739, respectively. The aggregate fair value of restricted stock units vested during the year ended December 31, 2017, 2016 and 2015 was $12,137, $10,311 and $6,261, respectively.

Included in the grants of 2017 restricted stock units are performance restricted stock units for which vesting is contingent upon meeting various financial targets to support growth initiatives. The Company granted 448,974 performance restricted stock units to officers and certain employees with an aggregate grant-date fair value of $12,425. Vesting is contingent upon meeting various financial targets to support growth initiatives through December 31, 2017. The actual number of shares issued upon vesting could range from 0% to 100%. As of December 31, 2017, there were 652,223 performance restricted stock units outstanding with a weighted average grant-date fair value of $29.39 per unit, of which 187,026 units with a weighted average grant-date fair value of $31.61 per unit were expected to vest.

Stock Options

The following is a summary of the option activity for the year ended December 31, 2017:

	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding balance at December 31, 2016		727,559		$	8.09
Granted		-			-
Exercised		(463,870	)		7.45
Forfeited or expired		(534	)		4.77
Outstanding balance at December 31, 2017		263,155		$	9.22		4.0	$	4,680
Exercisable at December 31, 2017		263,155		$	9.22		4.0	$	4,680
Vested and expected to vest at December 31, 2017		263,155		$	9.22		4.0	$	4,680

The aggregate intrinsic value of employee options exercised during the years ended December 31, 2017, 2016, and 2015 was $10,829, $21,117 and $18,873, respectively.

No stock options were granted during the years ended December 31, 2017, 2016 and 2015.

Stockholders' Deficit

12 Months Ended

Dec. 31, 2017

Equity [Abstract]

Stockholders' Deficit

11. Stockholders’ Deficit

Preferred stock

The Company has 5,000,000 shares of preferred stock authorized all of which is undesignated.

Common Stock

The holders of common stock are entitled to one vote for each share. The voting, dividend and liquidation rights of the holders of common stock are subject to and qualified by the rights, powers and preferences of the holders of preferred stock.

The Company maintains the Benefitfocus, Inc. 2016 Employee Stock Purchase Plan (“ESPP”) pursuant to which the Company has reserved 134,792 shares of its common stock for purchase by its employees who meet certain criteria. Under the ESPP, eligible employees may purchase the Company’s common stock through accumulated payroll deductions. Options to purchase shares are granted twice yearly on or about January 1 and July 1 and exercisable on or about the succeeding June 30 and December 31, respectively, of each year. Shares are purchased at acquisition prices equal to 95% of the fair market value of the Company’s common stock at the purchase date. No participant may purchase more than $12 worth of the Company’s common stock in a six-month offering period. As of December 31, 2017, contributions to purchase 7,039 shares had been received but not yet issued.

At December 31, 2017, the Company had reserved a total of 4,967,415 of its authorized 50,000,000 shares of common stock for future issuance as follows:

Outstanding stock options			263,155
Restricted stock units			1,937,014
Available for future issuance under stock award plans			2,632,454
Available for future issuance under ESPP			134,792
Total common shares reserved for future issuance			4,967,415

On February 24, 2015 and in conjunction with the amendment to the commercial contract described in Note 15, the Company entered into a Securities Purchase Agreement to sell shares of its common stock to Mercer, a customer of the Company. Pursuant to the agreement, on the same date, the Company sold 2,817,526 shares of its common stock to Mercer for $26.50 per share or an aggregate of $74,664. At the same time, the Company also issued Mercer a warrant to purchase up to an additional 580,813 shares of its common stock for $26.50 per share at any time during the 30-month term of the warrant. The agreement, among other things, includes certain standstill provisions and prevents Mercer from disposing of its shares of Company common stock until the earlier of December 31, 2017, the expiration or termination of the Mercer Exchange Software as a Service Agreement, as amended between the Company and Mercer Health & Benefits, LLC, the date on which Mercer and its affiliates own less than 75% of the shares it purchased pursuant to the Securities Purchase Agreement, and the date on which Mercer and its affiliates own less than 5% of the outstanding common stock of the Company. The Company received all of the proceeds from this sale of shares and is using the proceeds for working capital and other general corporate purposes. On August 24, 2017, the warrant to purchase 580,813 shares of common stock expired unexercised.

The Stock Purchase Agreement, warrant agreement and amended commercial contract are considered part of a single arrangement and accounted for in accordance with the multiple-element arrangement guidance outlined in ASC 605-25, Revenue: Multiple-Element Arrangements. The aggregate consideration from the arrangement was allocated to the units of accounting in the arrangement based on their estimated relative selling price, which resulted in $74,331 of consideration being allocated to common stock and warrant net of issuance costs.

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	12. Employee Benefit Plan The Company maintains a qualified defined contribution plan under Section 401(k) of the U.S. Internal Revenue Code (the “401(k) Plan”) covering substantially all employees. Employees are eligible to participate in the 401(k) Plan after one day of service and upon attainment of age 21, and may elect to defer an amount or percentage of their annual compensation up to amounts prescribed by law. The Company makes discretionary matching contributions to employee plan accounts. During each of the years ended December 31, 2017, 2016 and 2015, the Company matched 50% of the employees’ contribution, with the match limited to 3% of qualifying compensation. Employee vesting in matching company contributions occurs at a rate of 20% per year after one year of service. During the years ended December 31, 2017, 2016, and 2015, employer matching contributions were $3,020, $2,649 and $2,570, respectively.

Income Taxes

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Income Taxes

13. Income Taxes

The Company files income tax returns in the U.S. for federal and various state jurisdictions. The Company is subject to U.S. federal income tax examination for calendar tax years 2010 through 2016 as well as state income tax examinations for various years depending on statutes of limitations of those jurisdictions.

The following summarizes the components of income tax expense for the years ended December 31:

Current:	2017		2016		2015
Federal	$	-	$	-	$	-
State and local		15		17		25
Total current expense	$	15	$	17	$	25
Deferred:
Federal	$	-	$	-	$	-
State and local		-		-		-
Total deferred taxes	$	-	$	-	$	-

Reconciliation between the effect of applying the federal statutory rate and the effective income tax rate used to calculate the Company’s income tax provision is as follows for the years ended December 31:

	2017			2016			2015
Federal statutory rate		34.0	%		34.0	%		34.0	%
Effect of:
State income taxes, net of federal benefit		6.8	%		6.0	%		6.0	%
Change in state tax rates		0.8	%		2.6	%		1.7	%
Change in federal tax rates		(145.2	%)		0.0	%		0.0	%
Change in valuation allowance		98.7	%		(46.4	%)		(42.9	%)
State tax credits		0.7	%		4.1	%		2.5	%
Stock-based compensation		7.4	%		(0.1	%)		0.0	%
Section 162(m)		(2.4	%)		0.0	%		0.0	%
Other permanent items		(0.9	%)		(0.2	%)		(0.7	%)
Deferred true-up		0.0	%		0.0	%		(0.6	%)
Income tax provision effective rate		(0.1	%)		0.0	%		0.0	%

The significant components of the Company’s deferred tax asset and liability were as follows as of December 31:

	2017			2016
Deferred tax assets relating to:
Net operating loss carryforwards	$	69,452		$	65,467
Deferred revenue		12,275			19,255
Commissions and incentive accrual		547			1,563
Deferred rent		471			733
State tax credits		7,866			6,348
Stock-based compensation		4,060			5,199
Compensation and other accruals		2,539			5,222
Property and equipment and intangible assets		551			-
Total gross deferred tax assets		97,761			103,787
Deferred tax liabilities
Property and equipment and intangible assets	$	-		$	(578	)
Total gross deferred tax liabilities		-			(578	)
Deferred tax assets less liabilities		97,761			103,209
Less: valuation allowance		(97,761	)		(103,209	)
Net deferred tax asset (liability)	$	-		$	-

As of December 31, 2017 and 2016, the Company’s gross deferred tax was reduced by a valuation allowance of $97,761 and $103,209, respectively.

The valuation allowance decreased by $5,448 and increased by $17,894 during the years ended December 31, 2017 and 2016, respectively. The decrease in the valuation allowance in 2017 resulted primarily from the revaluation of the deferred tax assets and liabilities in connection with enactment of the Tax Cuts & Jobs Act (“Tax Reform”) on December 22, 2017. Among other things, the primary provision of Tax Reform impacting the Company is the reduction to the U.S. corporate income tax rate from 35% to 21%. The valuation allowance increase in 2016 resulted primarily from changes in the deferred tax assets related to the net operating loss carryforwards and deferred revenue.

On December 22, 2017, the SEC issued Staff Accounting Bulletin 118, which provides guidance on accounting for tax effects of Tax Reform when a company does not have all the necessary information available, prepared or analyzed in reasonable detail to complete its accounting for the effect of the changes in Tax Reform and provides a measurement period for companies to complete its accounting. As of December 31, 2017, the Company has completed its initial accounting for the income tax effects of Tax Reform except for the impact of state tax conformity of each change and further evaluation of executive compensation. The Company is not able to determine a reasonable estimate for these items and continues to account for these items based on the tax laws that were in effect immediately before the enactment of Tax Reform. The Company expects to complete its analysis during 2018 as states make known their conformity with federal tax laws and additional transition guidance is provided related to executive compensation.

The Company adopted the provisions of ASU 2016-09 as of January 1, 2017, which requires recognition through opening accumulated deficit of any pre-adoption date net operating loss carryforwards from nonqualified stock options and other employee share-based payments, as well as recognition of all income tax effects from share-based payments arising on or after the date of adoption in income tax expense. As a result, the Company was required to recognize through opening accumulated deficit the tax impact of pre-adoption date net operating loss carryforwards with remaining carryforward periods of more than 10 years. Due to the Company’s existing valuation allowance on deferred tax assets, the amount recognized in opening accumulated deficit was $0. The corresponding deferred tax asset recorded upon adoption was $18,383. However, the Company has determined that a valuation allowance is required against this amount due to the fact that it is more likely than not that the net operating loss carryforwards will expire before use. In addition, due to the valuation allowance, no windfall tax benefits were recognized in tax expense by the Company in the interim period of adoption as required by ASU 2016-09.

Net operating loss carryforwards for federal income tax purposes were approximately $253,946 and $183,528 at December 31, 2017 and 2016, respectively. State net operating loss carryforwards were $221,189 and $176,389 at December 31, 2017 and 2016, respectively. The federal net operating loss carryforwards will expire at various dates beginning in 2022 through 2036, if not utilized. Net operating loss carryforwards and credit carryforwards reflected above may be limited due to historical and future ownership changes.

South Carolina jobs tax credit and headquarters tax credit carryovers of $10,322 and $10,055 were available at December 31, 2017 and 2016, respectively. Headquarters credits are expected to be used to offset future state income tax license fees. The credits expire in various amounts during 2020 through 2032.

The Company follows FASB ASC 740-10 for accounting for unrecognized tax benefits. As of December 31, 2017, the Company had gross unrecognized tax benefits of $437.

A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows for the years ended December 31:

	2017		2016		2015
Balance at beginning of year	$	437	$	437	$	437
Additions based on tax positions related to the current year		-		-		-
Additions for tax positions in prior years		-		-		-
Reductions for tax positions of prior years		-		-		-
Reductions for tax positions due to lapse of statute		-		-		-
Settlements		-		-		-
Balance at end of year	$	437	$	437	$	437

At December 31, 2017 and 2016, none of the $437 liabilities for unrecognized tax benefits could impact the Company’s effective tax rate, if recognized. The Company does not expect the unrecognized tax benefits to change within the next twelve months.

The Company is subject to U.S. income taxes, as well as various taxes state and local jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal, state, and local income tax examinations by tax authorities for years before the tax year ended December 31, 2013, although carryforward attributes that were generated prior to 2013 may still be adjusted upon examination by the taxing authorities if they either have been used or will be used in a future period.

Segments and Geographic Information

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Segments and Geographic Information

14. Segments and Geographic Information

Operating segments are defined as components of an enterprise for which discrete financial information is available that is evaluated regularly by the chief operating decision maker (“CODM”) for purposes of allocating resources and evaluating financial performance. The Company’s CODM, the Chief Executive Officer, reviews financial information presented on a consolidated basis, accompanied by information about operating segments, for purposes of allocating resources and evaluating financial performance.

The Company’s reportable segments are based on the type of customer. The Company determined its operating segments to be: Employer, which derives substantially all of its revenue from customers that use the Company’s services for the provision of benefits to their employees, and administrators acting on behalf of employers; and Carrier, which derives substantially all of its revenue from insurance companies that provide coverage at their own risk.

Segments are evaluated based on gross profit. The Company does not allocate interest income, interest expense or income tax expense by segment. Accordingly, the Company does not report such information. Additionally, Employer and Carrier segments share the majority of the Company’s assets. Therefore, no segment asset information is reported.

	Year Ended December 31,
	2017		2016		2015
Revenue from external customers by segment:
Employer	$	163,978	$	140,522	$	94,842
Carrier		92,757		92,813		90,301
Total net revenue from external customers	$	256,735	$	233,335	$	185,143
Depreciation and amortization by segment:
Employer	$	10,209	$	7,950	$	6,024
Carrier		5,697		5,123		5,640
Total depreciation and amortization	$	15,906	$	13,073	$	11,664
Gross profit by segment
Employer	$	68,735	$	53,031	$	33,655
Carrier		63,844		59,623		48,637
Total gross profit by segment	$	132,579	$	112,654	$	82,292

Substantially all assets were held and all revenue was generated in the United States during the years ended December 31, 2017, 2016 and 2015.

Related Parties

12 Months Ended

Dec. 31, 2017

Related Parties

15. Related Parties

Related Party Leasing Arrangements

The Company leases its office space at its Charleston, South Carolina headquarters campus under the terms of three non-cancellable leases from entities with which two of the Company’s directors, significant stockholders, and executives are affiliated. The Company’s headquarters building lease and an additional building lease are accounted for as build-to-suit leases and recorded as financing obligations in the Consolidated Balance Sheets. The remaining lease, also for office space, was accounted for as an operating lease during 2016 and periods prior and as a capital lease in 2017 and after. The Company executed an amendment to each of the three lease agreements on December 12, 2016. These amendments extended the term of the leases to December 31, 2031. The leases contain options to renew the leases for five additional years. The arrangements provide for 3.0% fixed annual rent increases. In addition to extending the lease term, the amendment to the lease for the Company’s Customer Success Center, a 145,800 square foot building on its campus, which commenced January 1, 2015:

•

extended from December 13, 2016 to December 31, 2018 the term of an option that allows the Company to require the lessor to build a two-story building, including potentially for a welcome center of approximately 18,500 square feet on its campus (“Building 5”) for the Company to lease,

•

waived certain accrued and future carrying costs and termination fees payable to the lessor by the Company under the existing option in the amount of $1,223, and

•

reduced the annual rent increases for the Customer Success Center from 3% to 2% contingent upon construction of Building 4 described below.

On December 12, 2016 and in conjunction with the lease amendments, the Company also executed a cancellable lease agreement with an entity which two of the Company’s directors, significant stockholders, and executives are affiliated. Pursuant to the agreement the lessor will construct a building of approximately 145,800 square feet on its campus for the Company to accommodate anticipated future growth (“Building 4”). The target commencement date of the lease is July 1, 2019 with a term of 15 years. Under the terms of the lease, the Company agrees to commence construction on or about April 1, 2018, but can terminate the lease prior to that time, subject to payment of reasonable, documented, and agreed-to out-of-pocket costs with respect to the lease and building to date. If the Company delays beginning construction past December 31, 2018, the lessor may terminate the lease. The Company may renew the lease upon 365 days’ notice to the lessor for five additional one-year terms, provided that the Company is not in default at the time of its request. Significant terms of the lease for Building 4 include annual rent for the first year of the lease of $30.05 per square foot of rentable area with annual rent increases of 2% of the rent paid for the preceding lease year. If the Company exercises its option to cause the construction of Building 5, the term of the lease will reset to 15 years from the date the Company begins paying rent for Building 5.

In connection with the cancellable lease for Building 4 and the option for Building 5 described above, the leasing entity meets the criteria to be a variable interest entity. The Company is not the primary beneficiary of the leasing entity, as the activities that are most significant to the leasing entity’s economic performance, consisting of financing, development, management, and sale of office facilities, are directed by another party. As such, the Company is not required to consolidate the entity as the primary beneficiary. The lease terms would not include a residual value guarantee, fixed-price purchase option, or similar feature that would obligate the Company to absorb decreases in value or would entitle the Company to participate in increases in the value of Buildings 4 or 5. The Company has not and does not intend to provide financial or other support to the leasing entity. The Company’s maximum exposure, assuming the exercise of the option, would consist of rent to be paid over the 15-year term of the lease, construction cost overruns, agreed upon pre-construction costs incurred prior to termination and operating expenses in excess of a certain threshold. The Company’s maximum exposure currently cannot be quantified.

Payments related to these agreements were $10,328, $10,417, and $11,940 for the years ended December 31, 2017, 2016 and 2015, respectively. Amounts due to the related parties were recorded as $901 and $854 in “Accrued Expenses” as of December 31, 2017 and 2016, respectively.

Related Party Travel Expenses

The Company utilizes the services of various companies that are owned and controlled by one of the Company’s significant stockholders and executives. Expenses related to these companies were $20, $80 and $127 for the years ended December 31, 2017, 2016 and 2015 respectively, and consist of project management and air travel related to the operations of the business. No amounts were due to the related parties as of December 31, 2017 and 2016.

Related Party Revenues

As disclosed in Note 11, the Company entered into a Stock Purchase Agreement with Mercer, a customer, on February 24, 2015. As a result of this transaction, Mercer became a related party by virtue of beneficially owning more than 10% of the voting interest of the Company. At the same time, the Company entered into an amendment of its commercial contract with Mercer. The amendment to the commercial contract, among other things, expanded certain terms and conditions of the existing relationship between the Company and Mercer and its affiliates. On August 24, 2017, Mercer’s warrant to purchase common stock of the Company expired unexercised resulting in Mercer’s beneficial ownership of the Company falling below 10%. Accordingly, as of that date, the Company no longer considers Mercer a related party. As of December 31, 2017, Mercer beneficially owned 9.0% of the Company’s outstanding common stock. For the period January 1, 2017 to August 24, 2017, revenue from Mercer was $18,638. For the years ended December 31, 2016 and 2015, revenue from Mercer was $26,720 and $13,552, respectively. Revenue from Mercer was reflected in “Revenues,” within the accompanying statements of operations. The amount due from Mercer was $4,626 as of December 31, 2016. The amount of deferred revenue associated with Mercer was and $7,683 as of December 31, 2016, and was reflected in the balances of deferred revenue in the consolidated balance sheets.

Related Party Revolving Line of Credit

As disclosed in Note 8, the Company amended its Senior Revolver at various times in 2016 and 2017. As part of the amendment in October 2016, Goldman Sachs Lending Partners, LLC was added to the lending syndicate. Goldman Sachs Lending Partners, LLC is an affiliate of The Goldman Sachs Group, Inc., as are the Goldman Sachs funds that owned approximately 19.9% of the Company’s outstanding common stock as of December 31, 2017. Goldman Sachs Lending Partners, LLC committed $10,000 to the revolving commitment and participates in amounts borrowed under the credit facility at a rate of approximately 10.5%. Accordingly, approximately $5,906 of the $56,246 outstanding under the Senior Revolver as of December 31, 2017 was due to Goldman Sachs Lending Partners, LLC.

Selected Quarterly Financial Data (unaudited)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Selected Quarterly Financial Data (unaudited)

16. Selected Quarterly Financial Data (unaudited)

The following tables set forth selected unaudited quarterly statements of operations data for each of the eight quarters in the years ended December 31, 2017 and 2016.

	Quarter Ended
	December 31,			September 30,			June 30,			March 31,			December 31,			September 30,			June 30,			March 31,
	2017			2017			2017			2017			2016			2016			2016			2016
Consolidated Statements of Operations Data:
Revenue	$	66,763		$	62,453		$	63,348		$	64,171		$	62,647		$	58,022		$	57,874		$	54,792
Gross profit		33,503			31,986			34,520			32,570			30,125			28,910			28,124			25,495
Total operating expenses		37,285			35,601			35,996			37,215			35,189			35,434			37,215			36,984
Operating loss		(3,782	)		(3,615	)		(1,476	)		(4,645	)		(5,064	)		(6,524	)		(9,091	)		(11,489	)
Net loss	$	(7,004	)	$	(6,674	)	$	(4,506	)	$	(7,688	)	$	(7,099	)	$	(8,603	)	$	(11,004	)	$	(13,352	)
Net loss per common share (a)	$	(0.22	)	$	(0.21	)	$	(0.14	)	$	(0.25	)	$	(0.24	)	$	(0.29	)	$	(0.37	)	$	(0.46	)
Weighted-average common shares outstanding--basic and diluted		31,285,263			31,181,141			31,076,995			30,658,468			30,030,164			29,651,230			29,459,341			29,213,198

(a)	Quarterly and year-to-date computations of per share amounts are made independently. Therefore, the sum of the per-share amounts for the quarters may not agree with per share amounts for the year.

The quarterly unaudited consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements included in this report and include all adjustments, consisting only of normal recurring adjustments, that we consider necessary for a fair presentation of such information when read in conjunction with our annual audited consolidated financial statements and notes appearing in this report. The operating results for any quarter do not necessarily indicate the results for any subsequent period or for the entire fiscal year.

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	17. Subsequent Events Stock-Based Compensation During January 2018, the Company granted 54,040 restricted stock units to employees with an aggregate grant date fair value of $1,446. These restricted stock units generally vest in equal annual installments generally over 4 years from the grant date. The Company amortizes the fair value of the stock subject to the restricted stock units at the time of grant on a straight-line basis over the period of vesting. During January and February 2018, stock option exercises and vesting of restricted stock units resulted in the issuance of 23,458 shares of common stock. Revolving Line of Credit In January 2018, the Company repaid $24,000 that was previously borrowed under the Senior Revolver. Related Party Transaction In March 2018, the Company’s landlord extended the time period to commence construction of additional office space under its December 12, 2016 lease. Under the extension, the Company agrees to commence construction on or about April 1, 2019 and the target commencement date extends one year to July 1, 2020. The Company can terminate the lease prior to April 1, 2019.

Schedule II-Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2017

Valuation And Qualifying Accounts [Abstract]

Schedule II-Valuation and Qualifying Accounts

Schedule II—Valuation and Qualifying Accounts (in thousands)

	Balance at Beginning of Period		Additions Charged To Expense		Additions Charged Against Revenue			Deductions			Balance at End of Period
Allowance for doubtful accounts and returns:
Year Ended December 31, 2017	$	4,595	$	75	$	5,343		$	(6,547	)	$	3,466
Year Ended December 31, 2016	$	2,585	$	667	$	5,004		$	(3,661	)	$	4,595
Year Ended December 31, 2015	$	1,663	$	22	$	7,646		$	(6,746	)	$	2,585

	Balance at Beginning of Period		Additions Charged To Costs and Expenses (1)		Deductions (2)			Balance at End of Period
Deferred tax asset valuation allowance:
Year Ended December 31, 2017	$	103,209	$	32,113	$	(37,561	)	$	97,761
Year Ended December 31, 2016	$	85,315	$	17,894	$	-		$	103,209
Year Ended December 31, 2015	$	58,850	$	26,465	$	-		$	85,315
(1) Increase in valuation allowance is related to the generation of net operating losses and other deferred tax assets.
(2) Decrease in valuation on allowance is related to the change in the enacted tax rule.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Principles of Consolidation

Use of Estimates

Revenue and Deferred Revenue

Cost of Revenue

Cash and Cash Equivalents

Marketable Securities

Concentrations of Credit Risk

No customer represented more than 10% of total revenue for the year ended December 31, 2015.

Accounts Receivable and Allowance for Doubtful Accounts and Returns

Property and Equipment and Capitalized Software Development Costs

The estimated useful lives for significant property and equipment categories are generally as follows:

Buildings		30 years
Computers and related equipment		3-5 years
Purchased software and licenses		1-7 years
Developed software		3 years
Furniture and fixtures		7 years
Leasehold improvements		Lesser of estimated useful life of asset or lease term
Other equipment		5-12 years
Vehicles		5 years

Identifiable Intangible Assets

Impairment of Long-Lived Assets and Goodwill

Financing Obligations

Financing obligations also include liabilities for the purchase of software licenses.

Sales Commissions

Sales commissions are generally expensed when the sales contract is executed by the customer.

Advertising

The Company expenses advertising costs as they are incurred. Direct advertising costs for the years ended December 31, 2017, 2016, and 2015 were $168, $635 and $435, respectively.

Comprehensive Loss

The Company’s net loss equals comprehensive loss for all periods presented.

Stock-Based Employee Compensation

Income Taxes

Basic and Diluted Net Loss per Common Share

Recent Accounting Pronouncements

The Company will adopt the new standard effective January 1, 2018 using the full retrospective transition method and recast each prior reporting period presented.

The more significant impacts of the new standard to the Company are currently expected to be as follows:

•

The Company’s historical net cash flows provided by or used in operating, investing, and financing activities will not be impacted by adoption of the new revenue standard.

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Estimated Useful Lives for Significant Property and Equipment

The estimated useful lives for significant property and equipment categories are generally as follows:

Buildings		30 years
Computers and related equipment		3-5 years
Purchased software and licenses		1-7 years
Developed software		3 years
Furniture and fixtures		7 years
Leasehold improvements		Lesser of estimated useful life of asset or lease term
Other equipment		5-12 years
Vehicles		5 years

Net Loss Per Common Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Common Share Equivalent Securities Excluded from Calculation of Weighted-Average Common Shares Outstanding

The following common share equivalent securities have been excluded from the calculation of weighted-average common shares outstanding because the effect is anti-dilutive for the periods presented:

	Year Ended December 31,
Anti-Dilutive Common Share Equivalents	2017		2016		2015
Restricted stock units		1,937,014		1,467,811		1,017,450
Stock options		263,155		727,559		1,684,843
Warrant to purchase common stock		-		580,813		580,813
Employee Stock Purchase Plan		7,039		3,964		-
Total anti-dilutive common share equivalents		2,207,208		2,780,147		3,283,106

Basic and Diluted Net Loss per Common Share

Basic and diluted net loss per common share is calculated as follows:

	Year Ended December 31,
	2017			2016			2015
Numerator:
Net loss	$	(25,872	)	$	(40,058	)	$	(62,084	)
Net loss attributable to common stockholders	$	(25,872	)	$	(40,058	)	$	(62,084	)
Denominator:
Weighted-average common shares outstanding, basic and diluted		31,052,378			29,589,857			28,344,680
Net loss per common share, basic and diluted	$	(0.83	)	$	(1.35	)	$	(2.19	)

Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2017

Investments Debt And Equity Securities [Abstract]

Schedule of Marketable Securities

The following presents information about the Company’s marketable securities as of December 31:

	2016
Aggregate cost basis and net carrying amount	$	2,007
Gross unrealized holding gains		-
Gross unrealized holding losses		-
Aggregate fair value determined by Level 2 inputs	$	2,007

Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

	December 31, 2017
Description	Level 1		Level 2		Level 3		Total
Cash Equivalents:
Money market mutual funds ⁽¹⁾	$	46,730	$	-	$	-	$	46,730
Total assets	$	46,730	$	-	$	-	$	46,730

	December 31, 2016
Description	Level 1		Level 2		Level 3		Total
Cash Equivalents:
Money market mutual funds ⁽¹⁾	$	51,285	$	-	$	-	$	51,285
Total assets	$	51,285	$	-	$	-	$	51,285

(1)

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2017

Property Plant And Equipment [Abstract]

Property and Equipment

Property and equipment consists of the following as of December 31:

	2017			2016
Buildings, leased	$	48,558		$	48,558
Computers and related equipment		35,728			33,924
Purchased software and licenses		27,317			25,982
Developed software		30,624			26,142
Furniture and fixtures		6,669			6,668
Leasehold improvements		4,289			4,348
Other equipment		2,260			2,072
Vehicles		146			111
Construction in progress		-			319
Total property and equipment, at cost		155,591			148,124
Accumulated depreciation and amortization		(82,910	)		(67,606	)
Property and equipment, net	$	72,681		$	80,518

Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill And Intangible Assets Disclosure [Abstract]

Acquisition-Related Intangible Assets

Information regarding the Company’s acquisition-related intangible assets is as follows:

	As of December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted- Average Remaining Useful Life (in years)
Trademarks	$	240	$	(240	)	$	-		-
Customer agreements		2,060		(1,910	)		150		0.6
Non-compete agreements		126		(126	)		-		-
Total	$	2,426	$	(2,276	)	$	150		0.6

	As of December 31, 2016
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted- Average Remaining Useful Life (in years)
Trademarks	$	240	$	(240	)	$	-		-
Customer agreements		2,060		(1,652	)		408		1.6
Non-compete agreements		126		(126	)		-		-
Total	$	2,426	$	(2,018	)	$	408		1.6

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments And Contingencies Disclosure [Abstract]

Future Minimum Operating Lease Payments

Future minimum lease payments are as follows:

	Operating Leases
Year Ending December 31,
2018	$	1,400
2019		1,429
2020		1,135
2021		1,101
2022		824
Thereafter		8,335
Total minimum lease payments	$	14,224

Financing Obligations

Financing obligations are allocated as follows:

	As of December 31,
	2017			2016
Buildings, build-to-suit	$	32,652		$	31,326
Software and support		1,581			2,339
Total financing obligations	$	34,233		$	33,665
Less: current portion		(1,283	)		(757	)
Financing obligations, net of current portion	$	32,950		$	32,908

Future Minimum Lease Payments

Future minimum lease payments are as follows:

	Capital Leases			Financing Obligations
Year Ending December 31,
2018	$	5,089		$	7,759
2019		4,981			6,859
2020		3,216			6,747
2021		2,941			6,949
2022		3,029			7,158
Thereafter		31,697			74,895
Total minimum lease and financing obligation payments		50,953		$	110,367
Less: executory costs		(5,542	)
Less: imputed interest		(20,624	)
Less: current portion		(2,140	)
Capital lease obligations, net of current portion	$	22,647

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Number of Awards Outstanding

	Outstanding at December 31,
Award type	2017		2016		2015
Restricted stock units		1,937,014		1,467,811		1,017,450
Stock options		263,155		727,559		1,684,843

Compensation Expense Related to Stock Options

	2017		2016		2015
Cost of revenue	$	2,508	$	2,798	$	1,950
Sales and marketing		4,953		3,213		2,861
Research and development		2,990		4,532		2,399
General and administrative		5,686		7,545		3,244
	$	16,137	$	18,088	$	10,454

Summary of Unvested Restricted Stock Units Activity

The summary of unvested restricted stock units is as follows:

	Restricted stock units			Weighted average grant date fair value
Unvested at December 31, 2016		1,467,811		$	34.33
Granted		1,142,253			28.90
Forfeited		(266,114	)		33.52
Vested		(406,936	)		35.23
Unvested at December 31, 2017		1,937,014		$	30.90

Summary of Option Activity

The following is a summary of the option activity for the year ended December 31, 2017:

	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding balance at December 31, 2016		727,559		$	8.09
Granted		-			-
Exercised		(463,870	)		7.45
Forfeited or expired		(534	)		4.77
Outstanding balance at December 31, 2017		263,155		$	9.22		4.0	$	4,680
Exercisable at December 31, 2017		263,155		$	9.22		4.0	$	4,680
Vested and expected to vest at December 31, 2017		263,155		$	9.22		4.0	$	4,680

Stockholders' Deficit (Tables)

12 Months Ended

Dec. 31, 2017

Equity [Abstract]

Shares of Common Stock Reserved for Future Issuance

At December 31, 2017, the Company had reserved a total of 4,967,415 of its authorized 50,000,000 shares of common stock for future issuance as follows:

Outstanding stock options			263,155
Restricted stock units			1,937,014
Available for future issuance under stock award plans			2,632,454
Available for future issuance under ESPP			134,792
Total common shares reserved for future issuance			4,967,415

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Summary of Components of Income Tax (Benefit) Expense

The following summarizes the components of income tax expense for the years ended December 31:

Current:	2017		2016		2015
Federal	$	-	$	-	$	-
State and local		15		17		25
Total current expense	$	15	$	17	$	25
Deferred:
Federal	$	-	$	-	$	-
State and local		-		-		-
Total deferred taxes	$	-	$	-	$	-

Reconciliation Between Effect of Applying Federal Statutory Rate and Effective Income Tax Rate Used to Calculate Income Tax Provision

	2017			2016			2015
Federal statutory rate		34.0	%		34.0	%		34.0	%
Effect of:
State income taxes, net of federal benefit		6.8	%		6.0	%		6.0	%
Change in state tax rates		0.8	%		2.6	%		1.7	%
Change in federal tax rates		(145.2	%)		0.0	%		0.0	%
Change in valuation allowance		98.7	%		(46.4	%)		(42.9	%)
State tax credits		0.7	%		4.1	%		2.5	%
Stock-based compensation		7.4	%		(0.1	%)		0.0	%
Section 162(m)		(2.4	%)		0.0	%		0.0	%
Other permanent items		(0.9	%)		(0.2	%)		(0.7	%)
Deferred true-up		0.0	%		0.0	%		(0.6	%)
Income tax provision effective rate		(0.1	%)		0.0	%		0.0	%

Components of Deferred Tax Asset and Liability

The significant components of the Company’s deferred tax asset and liability were as follows as of December 31:

	2017			2016
Deferred tax assets relating to:
Net operating loss carryforwards	$	69,452		$	65,467
Deferred revenue		12,275			19,255
Commissions and incentive accrual		547			1,563
Deferred rent		471			733
State tax credits		7,866			6,348
Stock-based compensation		4,060			5,199
Compensation and other accruals		2,539			5,222
Property and equipment and intangible assets		551			-
Total gross deferred tax assets		97,761			103,787
Deferred tax liabilities
Property and equipment and intangible assets	$	-		$	(578	)
Total gross deferred tax liabilities		-			(578	)
Deferred tax assets less liabilities		97,761			103,209
Less: valuation allowance		(97,761	)		(103,209	)
Net deferred tax asset (liability)	$	-		$	-

Reconciliation of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows for the years ended December 31:

	2017		2016		2015
Balance at beginning of year	$	437	$	437	$	437
Additions based on tax positions related to the current year		-		-		-
Additions for tax positions in prior years		-		-		-
Reductions for tax positions of prior years		-		-		-
Reductions for tax positions due to lapse of statute		-		-		-
Settlements		-		-		-
Balance at end of year	$	437	$	437	$	437

Segments and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Segments and Geographic Information

	Year Ended December 31,
	2017		2016		2015
Revenue from external customers by segment:
Employer	$	163,978	$	140,522	$	94,842
Carrier		92,757		92,813		90,301
Total net revenue from external customers	$	256,735	$	233,335	$	185,143
Depreciation and amortization by segment:
Employer	$	10,209	$	7,950	$	6,024
Carrier		5,697		5,123		5,640
Total depreciation and amortization	$	15,906	$	13,073	$	11,664
Gross profit by segment
Employer	$	68,735	$	53,031	$	33,655
Carrier		63,844		59,623		48,637
Total gross profit by segment	$	132,579	$	112,654	$	82,292

Selected Quarterly Financial Data (unaudited) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Unaudited Quarterly Statements of Operations Data

The following tables set forth selected unaudited quarterly statements of operations data for each of the eight quarters in the years ended December 31, 2017 and 2016.

	Quarter Ended
	December 31,			September 30,			June 30,			March 31,			December 31,			September 30,			June 30,			March 31,
	2017			2017			2017			2017			2016			2016			2016			2016
Consolidated Statements of Operations Data:
Revenue	$	66,763		$	62,453		$	63,348		$	64,171		$	62,647		$	58,022		$	57,874		$	54,792
Gross profit		33,503			31,986			34,520			32,570			30,125			28,910			28,124			25,495
Total operating expenses		37,285			35,601			35,996			37,215			35,189			35,434			37,215			36,984
Operating loss		(3,782	)		(3,615	)		(1,476	)		(4,645	)		(5,064	)		(6,524	)		(9,091	)		(11,489	)
Net loss	$	(7,004	)	$	(6,674	)	$	(4,506	)	$	(7,688	)	$	(7,099	)	$	(8,603	)	$	(11,004	)	$	(13,352	)
Net loss per common share (a)	$	(0.22	)	$	(0.21	)	$	(0.14	)	$	(0.25	)	$	(0.24	)	$	(0.29	)	$	(0.37	)	$	(0.46	)
Weighted-average common shares outstanding--basic and diluted		31,285,263			31,181,141			31,076,995			30,658,468			30,030,164			29,651,230			29,459,341			29,213,198

(a)	Quarterly and year-to-date computations of per share amounts are made independently. Therefore, the sum of the per-share amounts for the quarters may not agree with per share amounts for the year.

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) ReportingUnit	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Customer	Jan. 01, 2017 USD ($)
Summary of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts	$ 654	$ 691
Finite lived intangibles, useful life	7 months 6 days
Number of reporting units \| ReportingUnit	2
Advertising costs	$ 168	635	$ 435
Accounting Standards Update 2016-09
Summary of Significant Accounting Policies [Line Items]
Cumulative effect adjustment to accumulated deficit				$ 391
Capitalized Software Development Costs
Summary of Significant Accounting Policies [Line Items]
Useful lives for property and equipment	3 years
Allowance for Returns
Summary of Significant Accounting Policies [Line Items]
Allowance for returns	$ 2,812	$ 3,904
Carrier Products (CRP) \| Accounting Standards Update ("ASU") 2014-09
Summary of Significant Accounting Policies [Line Items]
Amortization period of asset recognized costs	5 years
Customer Concentration Risk \| Accounts Receivable
Summary of Significant Accounting Policies [Line Items]
Concentration risk, percentage	12.00%	14.00%
Customer Concentration Risk \| Accounts Receivable \| Another Customer
Summary of Significant Accounting Policies [Line Items]
Concentration risk, percentage		13.00%
Customer Concentration Risk \| Total Revenue
Summary of Significant Accounting Policies [Line Items]
Number of customers exceeded 10% of total revenue \| Customer			0
Customer Concentration Risk \| Total Revenue \| Employer
Summary of Significant Accounting Policies [Line Items]
Concentration risk, percentage	12.00%	11.00%
Maximum
Summary of Significant Accounting Policies [Line Items]
Cash equivalents maturity period	3 months
Highly rated marketable securities	2 years
Weighted average maturity of portfolio of investments	9 months

Estimated Useful Lives for Significant Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2017
Buildings
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	30 years
Developed software
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	3 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	7 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	Lesser of estimated useful life of asset or lease term
Vehicles
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	5 years
Minimum \| Computers and Related Equipment
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	3 years
Minimum \| Purchased Software and Licenses
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	1 year
Minimum \| Other Equipment
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	5 years
Maximum \| Computers and Related Equipment
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	5 years
Maximum \| Purchased Software and Licenses
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	7 years
Maximum \| Other Equipment
Property, Plant and Equipment [Line Items]
Useful lives for property and equipment	12 years

Common Share Equivalents Securities Excluded From Calculation of Weighted Average Common Share Outstanding (Detail) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common share equivalents	2,207,208	2,780,147	3,283,106
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common share equivalents	1,937,014	1,467,811	1,017,450
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common share equivalents	263,155	727,559	1,684,843
Warrant to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common share equivalents	0	580,813	580,813
Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common share equivalents	7,039	3,964	0

Basic and Diluted Net Loss per Common Share (Detail) - USD ($)
$ / shares in Units, $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2016

Sep. 30, 2016

Jun. 30, 2016

Mar. 31, 2016

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Numerator:

Net loss

$ (7,004)

$ (6,674)

$ (4,506)

$ (7,688)

$ (7,099)

$ (8,603)

$ (11,004)

$ (13,352)

$ (25,872)

$ (40,058)

$ (62,084)

Net loss attributable to common stockholders

$ (25,872)

$ (40,058)

$ (62,084)

Denominator:

Weighted-average common shares outstanding, basic and diluted

31,285,263

31,181,141

31,076,995

30,658,468

30,030,164

29,651,230

29,459,341

29,213,198

31,052,378

29,589,857

28,344,680

Net loss per common share, basic and diluted

$ (0.22)

^[1]

$ (0.21)

^[1]

$ (0.14)

^[1]

$ (0.25)

^[1]

$ (0.24)

^[1]

$ (0.29)

^[1]

$ (0.37)

^[1]

$ (0.46)

^[1]

$ (0.83)

$ (1.35)

$ (2.19)

[1]	Quarterly and year-to-date computations of per share amounts are made independently. Therefore, the sum of the per-share amounts for the quarters may not agree with per share amounts for the year.

Marketable Securities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017
Gain (Loss) on Investments [Line Items]
Marketable securities		$ 0
Unrealized loss position on investments	$ 0
Maximum
Gain (Loss) on Investments [Line Items]
Held-to-maturity securities, contractual maturity period	1 month

Schedule of Marketable Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]
Aggregate cost basis and net carrying amount	$ 0	$ 2,007
Gross unrealized holding gains		0
Gross unrealized holding losses		0
Aggregate fair value determined by Level 2 inputs		$ 2,007

Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($)
$ in Thousands

Dec. 31, 2017

Dec. 31, 2016

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Total assets

$ 46,730

$ 51,285

Money market mutual funds

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Cash Equivalents

^[1]

46,730

51,285

Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Total assets

46,730

51,285

Level 1 | Money market mutual funds

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Cash Equivalents

^[1]

46,730

51,285

Level 2

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Total assets

Level 2 | Money market mutual funds

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Cash Equivalents

^[1]

Level 3

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Total assets

Level 3 | Money market mutual funds

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Cash Equivalents

^[1]

$ 0

[1]

Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 155,591	$ 148,124
Accumulated depreciation and amortization	(82,910)	(67,606)
Property and equipment, net	72,681	80,518
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	48,558	48,558
Computers and Related Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	35,728	33,924
Purchased Software and Licenses
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27,317	25,982
Developed software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	30,624	26,142
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	6,669	6,668
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,289	4,348
Other Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,260	2,072
Vehicles
Property, Plant and Equipment [Line Items]
Property and equipment, gross	146	111
Construction in progress, build-to-suit
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 0	$ 319

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 15,906	$ 13,073	$ 11,664
Fixed assets acquired under capital lease	35,761	35,761
Accumulated depreciation of assets under capital leases	9,633	5,194
Capitalized software cost gross	4,482	5,242
Amortization of capitalized software cost	3,257	2,857	2,587
Capitalized software cost net	7,660	6,435
Property and Equipment
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 15,648	$ 12,816	$ 11,378

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill	$ 1,634,000	$ 1,634,000
Goodwill gross carrying amount	3,304,000	3,304,000
Goodwill accumulated impairment losses	(1,670,000)	(1,670,000)
Amortization expense related to acquisition of intangible assets	258,000	257,000	$ 286,000
Amortization expense for intangible assets expected for 2018	150,000
Impairment of intangible assets	$ 0	$ 0	$ 0

Acquisition-Related Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,426	$ 2,426
Accumulated Amortization	(2,276)	(2,018)
Net Carrying Amount	$ 150	$ 408
Weighted- Average Remaining Useful Life (in years)	7 months 6 days	1 year 7 months 6 days
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 240	$ 240
Accumulated Amortization	(240)	(240)
Net Carrying Amount	$ 0	$ 0
Weighted- Average Remaining Useful Life (in years)	0 years	0 years
Customer Agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,060	$ 2,060
Accumulated Amortization	(1,910)	(1,652)
Net Carrying Amount	$ 150	$ 408
Weighted- Average Remaining Useful Life (in years)	7 months 6 days	1 year 7 months 6 days
Non-compete Agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 126	$ 126
Accumulated Amortization	(126)	(126)
Net Carrying Amount	$ 0	$ 0
Weighted- Average Remaining Useful Life (in years)	0 years	0 years

Revolving Line of Credit - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Oct. 31, 2016	Feb. 28, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013	Aug. 27, 2013
Line Of Credit Facility [Line Items]
Proceeds from line of credit borrowing			$ 105,000,000	$ 84,000,000	$ 57,492,000
Payments on revolving line of credit			89,000,000	74,000,000	44,903,000
Hardware And Software
Line Of Credit Facility [Line Items]
Proceeds from line of credit borrowing			105,000,000	84,000,000	39,246,000
Payments on revolving line of credit			$ 89,000,000	$ 74,000,000	$ 27,246,000
Revolving Line of Credit
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity							$ 15,000,000
Before Amendment
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity						$ 15,000,000
After Amendment
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity						$ 35,000,000
Senior Revolving Line of Credit
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity	$ 95,000,000	$ 60,000,000
Proceeds from line of credit borrowing		18,246,000
Payments on revolving line of credit		17,657,000
Administrative and legal fees related to the issuance of line of credit		589,000
Debt issuance fees capitalized	$ 379,000	$ 591,000
Line of credit facility, expiration period		3 years
Line of credit facility expiration date	Feb. 20, 2020		Feb. 29, 2020
Amount outstanding under credit facility			$ 56,246,000
Amount available to borrow under line of credit			$ 16,102,000
Line of credit facility interest rate			5.50%
Senior Revolving Line of Credit \| Minimum
Line Of Credit Facility [Line Items]
Interest rate margin to be added on prime rate	0.75%	1.00%
Line of credit facility, unused capacity, commitment fee percentage		0.30%
Senior Revolving Line of Credit \| Maximum
Line Of Credit Facility [Line Items]
Interest rate margin to be added on prime rate	1.25%	1.50%
Line of credit facility, unused capacity, commitment fee percentage		0.375%

Commitments and Contingencies - Additional Information (Detail)			12 Months Ended
	Dec. 31, 2016 USD ($) Building	Dec. 12, 2016 ft² Lease_Agreements Option $ / ft²	Dec. 31, 2017 USD ($) ft² Building Lease_Agreements	Dec. 31, 2016 USD ($) Building	Dec. 31, 2015 USD ($)	Dec. 31, 2013 USD ($)
Commitments And Contingencies Disclosure [Line Items]
Number of buildings leased \| Building	3		3	3
Rent for land leases expiration year			2031
Lease yearly expenses			$ 1,605,000	$ 4,403,000	$ 4,376,000
Operating lease renewal option term				15 years
Percentage of present value of minimum lease payments at beginning of lease term of fair value of leased property				90.00%
Aggregate payments under lease				$ 48,600,000
Executory costs	$ 5,938,000		5,542,000	5,938,000
Capital lease obligation			20,571,000
Software and maintenance
Commitments And Contingencies Disclosure [Line Items]
Financing obligation			6,570,000
Lease and financing arrangement
Commitments And Contingencies Disclosure [Line Items]
Financing obligation	33,665,000		34,233,000	33,665,000
Financing Obligation
Commitments And Contingencies Disclosure [Line Items]
Financing obligation			110,367,000
Headquarters building, build-to-suit \| Lease and financing arrangement
Commitments And Contingencies Disclosure [Line Items]
Financing obligation	$ 31,326,000		32,652,000	$ 31,326,000
Headquarters building, build-to-suit \| Financing Obligation
Commitments And Contingencies Disclosure [Line Items]
Financing obligation			$ 108,659,000
Minimum
Commitments And Contingencies Disclosure [Line Items]
Operating lease expiration year			2018
Minimum \| Property and Equipment
Commitments And Contingencies Disclosure [Line Items]
Capital lease agreement period			2 years
Interest rate under lease agreement			0.50%
Maximum
Commitments And Contingencies Disclosure [Line Items]
Operating lease expiration year			2022
Maximum \| Property and Equipment
Commitments And Contingencies Disclosure [Line Items]
Capital lease agreement period			5 years
Interest rate under lease agreement			10.00%
Capital Lease
Commitments And Contingencies Disclosure [Line Items]
Number of buildings leased \| Building	1		1	1
Build to Suit and Failed Sale Leaseback
Commitments And Contingencies Disclosure [Line Items]
Number of buildings leased \| Building			2
Build-to-suit Lease
Commitments And Contingencies Disclosure [Line Items]
Option to extend lease term						36 months
Build-to-suit Lease \| Maximum
Commitments And Contingencies Disclosure [Line Items]
Annual costs prior to exercise of an option to lease space in two additional adjacent buildings						$ 466,000
Termination fee if the company terminates an option to lease space in two additional adjacent buildings						$ 757,000
Non-Cancellable Leases \| Related Party Leasing Arrangements
Commitments And Contingencies Disclosure [Line Items]
Operating lease renewal option term			5 years
Number of Lease agreements \| Lease_Agreements		3	3
Extended leases, expiration date			Dec. 31, 2031
Area of building, lessor to build \| ft²			18,500
Waived accrued and future carrying costs and termination fees payable			$ 1,223,000
Percentage of annual rent increase			3.00%
Reduced percentage of annual rent increase contingent upon construction of building			2.00%
Area of building (in square foot) \| ft²			145,800
Lease first occupied date			Jan. 01, 2015
Carrying and termination fees amortization period			15 years
Lease commencement date			Jan. 01, 2015
Cancelable Lease Agreement \| Related Party Leasing Arrangements
Commitments And Contingencies Disclosure [Line Items]
Operating lease renewal option term		1 year
Percentage of annual rent increase		2.00%
Area of building (in square foot) \| ft²		145,800
Lease commencement date		Jul. 01, 2019
Lease agreement period		15 years
Notice period to renew lease		365 days
Number of options to extend operating lease \| Option		5
Annual rent per square foot \| $ / ft²		30.05
Lease term reset to original term when new building construction commence	15 years		15 years

Future Minimum Operating Lease Payments (Detail) $ in Thousands	Dec. 31, 2017 USD ($)
Commitments And Contingencies Disclosure [Abstract]
2018	$ 1,400
2019	1,429
2020	1,135
2021	1,101
2022	824
Thereafter	8,335
Total minimum lease payments	$ 14,224

Financing Obligations (Detail) - Lease and financing arrangement - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Contractual Obligation [Line Items]
Financing obligations	$ 34,233	$ 33,665
Less: current portion	(1,283)	(757)
Financing obligations, net of current portion	32,950	32,908
Headquarters building, build-to-suit
Contractual Obligation [Line Items]
Financing obligations	32,652	31,326
Software and Support
Contractual Obligation [Line Items]
Financing obligations	$ 1,581	$ 2,339

Future Minimum Lease Payments (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Capital Leases
2018	$ 5,089
2019	4,981
2020	3,216
2021	2,941
2022	3,029
Thereafter	31,697
Total minimum lease payments	50,953
Less: executory costs	(5,542)	$ (5,938)
Less: imputed interest	(20,624)
Less: current portion	(3,423)	(2,604)
Capital lease obligations, net of current portion	22,647
Financing Obligations
Executory costs	5,542	$ 5,938
Financing Obligation
Financing Obligations
2018	7,759
2019	6,859
2020	6,747
2021	6,949
2022	7,158
Thereafter	74,895
Total minimum lease and financing obligation payments	110,367
Capital Lease Obligations
Capital Leases
Less: current portion	$ (2,140)

Stock-Based Compensation - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares reserved for issuance under stock plans				4,832,623
Total compensation cost related to nonvested awards not yet recognized	$ 31,608,000
Total compensation cost related to nonvested awards not yet recognized period	2 years 8 months 26 days
Number of restricted stock units expected to vest	1,471,818
Intrinsic value of restricted stock units expected to vest	$ 39,739,000
Aggregate fair value of restricted stock units vested	$ 12,137,000	$ 10,311,000	$ 6,261,000
Number of restricted stock units outstanding	1,937,014	1,467,811	1,017,450
Restricted stock units, aggregate grant date fair value	$ 28.90
Number of restricted stock units, granted	1,142,253
Aggregate intrinsic value of employee options exercised	$ 10,829,000	$ 21,117,000	$ 18,873,000
Stock-based compensation, option granted	0	0	0
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock plan vesting period	4 years
Performance Based Restricted Stock Units R S Us
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting date	Dec. 31, 2017
Number of restricted stock units outstanding	652,223
Restricted stock units, aggregate grant date fair value	$ 29.39
Number of restricted stock units, granted	187,026
Restricted stock units, aggregate grant date fair value	$ 31,610
Performance Based Restricted Stock Units R S Us \| Vest on December 31,2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock units, granted	448,974
Restricted stock units, aggregate grant date fair value	$ 12,425,000
Performance Based Restricted Stock Units R S Us \| Vest on December 31,2017 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued vesting percentage	0.00%
Performance Based Restricted Stock Units R S Us \| Vest on December 31,2017 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued vesting percentage	100.00%
2012 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share allocated to stock option plan	2,632,454
Stock plan vesting period	4 years
Stock plan expiration period from grant date	10 years

Number of Awards Outstanding (Detail) - shares	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Restricted stock units	1,937,014	1,467,811	1,017,450
Stock options	263,155	727,559	1,684,843

Compensation Expense Related to Stock Options (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 16,137	$ 18,088	$ 10,454
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	2,508	2,798	1,950
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	4,953	3,213	2,861
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	2,990	4,532	2,399
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 5,686	$ 7,545	$ 3,244

Summary of Unvested Restricted Stock Units Activity (Detail)	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Restricted stock units
Restricted stock units, beginning balance \| shares	1,467,811
Restricted stock units, granted \| shares	1,142,253
Restricted stock units, Forfeited \| shares	(266,114)
Restricted stock units, Vested \| shares	(406,936)
Restricted stock units, ending balance \| shares	1,937,014
Weighted average grant date fair value
Weighted average grant date fair value, beginning balance \| $ / shares	$ 34.33
Weighted average grant date fair value, granted \| $ / shares	28.90
Weighted average grant date fair value, Forfeited \| $ / shares	33.52
Weighted average grant date fair value, Vested \| $ / shares	35.23
Weighted average grant date fair value, ending balance \| $ / shares	$ 30.90

Summary of Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock options
Beginning Balance	727,559	1,684,843
Granted	0	0	0
Exercised	(463,870)
Forfeited or expired	(534)
Ending Balance	263,155	727,559	1,684,843
Exercisable	263,155
Vested and expected to vest	263,155
Weighted Average Exercise Price
Beginning Balance		$ 8.09
Granted	$ 0
Exercised	7.45
Forfeited or expired	4.77
Ending Balance	9.22		$ 8.09
Exercisable	9.22
Vested and expected to vest	$ 9.22
Weighted Average Remaining Contractual Term
Outstanding	4 years
Exercisable	4 years
Vested and Expected to Vest	4 years
Aggregate Intrinsic Value
Outstanding	$ 4,680
Exercisable	4,680
Vested and Expected to vest	$ 4,680

Stockholders' Deficit - Additional Information (Detail) - USD ($)			12 Months Ended
	Aug. 24, 2017	Feb. 24, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2016
Schedule Of Stockholders Equity [Line Items]
Preferred stock, shares authorized			5,000,000	5,000,000
Common stock, authorized shares reserved for future issuance			4,967,415
Common stock, shares authorized			50,000,000	50,000,000
Proceeds from issuance of common stock and warrant, net of issuance costs			$ 0	$ 0	$ 74,538,000
Mercer LLC
Schedule Of Stockholders Equity [Line Items]
Stock issued, shares		2,817,526
Stock issued, price per share		$ 26.50
Stock issued, value		$ 74,664,000
Maximum number of shares to be issued under warrant agreement		580,813
Warrant exercise price per share		$ 26.50
Warrant term		30 months
Warrants to purchase of common stock shares	580,813
Proceeds from issuance of common stock and warrant, net of issuance costs			$ 74,331,000
Mercer LLC \| Maximum
Schedule Of Stockholders Equity [Line Items]
Common stock ownership percentage in Mercer Health & Benefits, LLC		75.00%
Outstanding common stock ownership percentage		5.00%
Employee Stock Purchase Plan
Schedule Of Stockholders Equity [Line Items]
Common stock shares reserved for purchase						134,792
Percentage of common stock shares purchased on fair market value			95.00%
Maximum value of stock to be purchased per employee during the offering period			$ 12
Contributions received but not yet issued			7,039

Common Stock for Future Issuance (Detail) - shares	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class Of Stock [Line Items]
Outstanding stock options	263,155	727,559	1,684,843
Restricted stock units	1,937,014	1,467,811	1,017,450
Total common shares reserved for future issuance	4,967,415
Stock Award Plans
Class Of Stock [Line Items]
Common stock available for future issuance	2,632,454
ESPP
Class Of Stock [Line Items]
Common stock available for future issuance	134,792

Employee Benefit Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Contribution Plan Disclosure [Line Items]
Defined benefit plan service period of employees to be eligible to participate in 401(k) plan	1 day
Eligible age of participation in 401 (k) plan	Employees are eligible to participate in the 401(k) Plan after one day of service and upon attainment of age 21
Employers matching contribution, percent	50.00%	50.00%	50.00%
Percentage of employee vesting amount on matching company contribution	20.00%	20.00%	20.00%
Employee's service requisite period for vesting matching company contribution	1 year	1 year	1 year
Employers matching contribution	$ 3,020	$ 2,649	$ 2,570
Maximum
Defined Contribution Plan Disclosure [Line Items]
Employers matching contribution percent of qualifying compensation	3.00%	3.00%	3.00%

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Income Taxes [Line Items]
Deferred tax valuation allowance		$ 97,761,000	$ 103,209,000
(Decrease) increase in valuation allowance		$ (5,448,000)	$ 17,894,000
U.S. corporate income tax rate		34.00%	34.00%	34.00%
Net operating loss carryforwards with remaining carryforward minimum period		10 years
Accumulated deficit		$ 0
Deferred tax assets recorded upon adoption		18,383,000
Gross unrecognized tax benefits		437,000	$ 437,000	$ 437,000	$ 437,000
Liabilities For Unrecognized Tax Benefit		437,000	437,000
Portion of unrecognized tax benefits for Company's effective tax rate		0	0
SOUTH CAROLINA
Schedule Of Income Taxes [Line Items]
Tax credit carryovers		10,322,000	10,055,000
Federal
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards		$ 253,946,000	183,528,000
Net operating loss carryforwards expiration, beginning year		2022
Net operating loss carryforwards expiration, ending year		2036
State and Local Jurisdiction
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards		$ 221,189,000	176,389,000
Unrecognized Tax Benefit
Schedule Of Income Taxes [Line Items]
Gross unrecognized tax benefits		437,000
Scenario, Forecast
Schedule Of Income Taxes [Line Items]
U.S. corporate income tax rate	21.00%
Corporate Headquarters
Schedule Of Income Taxes [Line Items]
Tax credit carryovers		$ 10,322,000	$ 10,055,000
Expiration of tax credit carryforward, beginning year		2020
Expiration of tax credit carryforward, ending year		2032
Minimum
Schedule Of Income Taxes [Line Items]
U.S. federal income tax examination year		2010
Maximum
Schedule Of Income Taxes [Line Items]
U.S. federal income tax examination year		2016

Summary of Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 0	$ 0	$ 0
State and local	15	17	25
Total current expense	15	17	25
Deferred:
Federal	0	0	0
State and local	0	0	0
Total deferred taxes	$ 0	$ 0	$ 0

Reconciliation Between Effect of Applying Federal Statutory Rate and Effective Income Tax Rate Used to Calculate Income Tax Provision (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal statutory rate	34.00%	34.00%	34.00%
State income taxes, net of federal benefit	6.80%	6.00%	6.00%
Change in state tax rates	0.80%	2.60%	1.70%
Change in federal tax rates	(145.20%)	0.00%	0.00%
Change in valuation allowance	98.70%	(46.40%)	(42.90%)
State tax credits	0.70%	4.10%	2.50%
Stock-based compensation	7.40%	(0.10%)	0.00%
Section 162(m)	(2.40%)	0.00%	0.00%
Other permanent items	(0.90%)	(0.20%)	(0.70%)
Deferred true-up	0.00%	0.00%	(0.60%)
Income tax provision effective rate	(0.10%)	0.00%	0.00%

Components of Deferred Tax Asset and Liability (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets relating to:
Net operating loss carryforwards	$ 69,452	$ 65,467
Deferred revenue	12,275	19,255
Commissions and incentive accrual	547	1,563
Deferred rent	471	733
State tax credits	7,866	6,348
Stock-based compensation	4,060	5,199
Compensation and other accruals	2,539	5,222
Property and equipment and intangible assets	551	0
Total gross deferred tax assets	97,761	103,787
Deferred tax liabilities
Property and equipment and intangible assets	0	(578)
Total gross deferred tax liabilities	0	(578)
Deferred tax assets less liabilities	97,761	103,209
Less: valuation allowance	(97,761)	(103,209)
Net deferred tax asset (liability)	$ 0	$ 0

Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Beginning balance	$ 437	$ 437	$ 437
Additions based on tax positions related to the current year	0	0	0
Additions for tax positions in prior years	0	0	0
Reductions for tax positions of prior years	0	0	0
Reductions for tax positions due to lapse of statute	0	0	0
Settlements	0	0	0
Ending balance	$ 437	$ 437	$ 437

Segments and Geographic Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 66,763	$ 62,453	$ 63,348	$ 64,171	$ 62,647	$ 58,022	$ 57,874	$ 54,792	$ 256,735	$ 233,335	$ 185,143
Depreciation and amortization									15,906	13,073	11,664
Gross profit	$ 33,503	$ 31,986	$ 34,520	$ 32,570	$ 30,125	$ 28,910	$ 28,124	$ 25,495	132,579	112,654	82,292
Employer
Segment Reporting Information [Line Items]
Net revenue from external customers									163,978	140,522	94,842
Depreciation and amortization									10,209	7,950	6,024
Gross profit									68,735	53,031	33,655
Carrier
Segment Reporting Information [Line Items]
Net revenue from external customers									92,757	92,813	90,301
Depreciation and amortization									5,697	5,123	5,640
Gross profit									$ 63,844	$ 59,623	$ 48,637

Related Parties - Additional Information (Detail)			8 Months Ended	12 Months Ended
Related Parties - Additional Information (Detail)	Dec. 31, 2016 USD ($)	Dec. 12, 2016 ft² Lease_Agreements Option Person $ / ft²	Aug. 24, 2017 USD ($)	Dec. 31, 2017 USD ($) ft² Lease_Agreements Person	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Oct. 31, 2016 USD ($)	Feb. 28, 2015 USD ($)
Related Party Transaction [Line Items]
Operating lease renewal option term					15 years
Lease operating expenses				$ 10,328,000	$ 10,417,000	$ 11,940,000
Due to related parties, current	$ 854,000			901,000	854,000
Accounts receivable, related party, net	4,626,000			0	4,626,000
Senior Revolving Line of Credit
Related Party Transaction [Line Items]
Revolving commitment amount from related party							$ 95,000,000	$ 60,000,000
Amount outstanding under credit facility				56,246,000
Stockholders and Executives
Related Party Transaction [Line Items]
Due to related parties, current	0			0	0
Service from related party				$ 20,000	80,000	127,000
Mercer LLC
Related Party Transaction [Line Items]
Percentage of beneficial ownership of common stock				9.00%
Revenue from related parties			$ 18,638,000		26,720,000	$ 13,552,000
Accounts receivable, related party, net	4,626,000				4,626,000
Deferred revenue	$ 7,683,000				$ 7,683,000
Mercer LLC \| Minimum
Related Party Transaction [Line Items]
Percentage of ownership interest sold by parent				10.00%
Mercer LLC \| Maximum
Related Party Transaction [Line Items]
Percentage of beneficial ownership of common stock			10.00%
Goldman Sachs Group, Inc.
Related Party Transaction [Line Items]
Outstanding common stock ownership percentage				19.90%
Goldman Sachs Group, Inc. \| Senior Revolving Line of Credit
Related Party Transaction [Line Items]
Revolving commitment amount from related party				$ 10,000,000
Percentage of loan amounts borrowed under credit facility				10.50%
Amount outstanding under credit facility				$ 56,246,000
Due to related party				$ 5,906,000
Related Party Leasing Arrangements \| Non-Cancellable Leases
Related Party Transaction [Line Items]
Number of stockholders and executives affiliated to leasing entity \| Person				2
Number of Lease agreements \| Lease_Agreements		3		3
Operating lease renewal option term				5 years
Percentage of annual rent increase				3.00%
Area of building (in square foot) \| ft²				145,800
Lease commencement date				Jan. 01, 2015
Extended leases, expiration date				Dec. 31, 2031
Area of building, lessor to build \| ft²				18,500
Waived accrued and future carrying costs and termination fees payable				$ 1,223,000
Reduced percentage of annual rent increase contingent upon construction of building				2.00%
Related Party Leasing Arrangements \| Cancelable Lease Agreement
Related Party Transaction [Line Items]
Number of stockholders and executives affiliated to leasing entity \| Person		2
Operating lease renewal option term		1 year
Percentage of annual rent increase		2.00%
Area of building (in square foot) \| ft²		145,800
Lease commencement date		Jul. 01, 2019
Lease agreement period		15 years
Notice period to renew lease		365 days
Number of options to extend operating lease \| Option		5
Annual rent per square foot \| $ / ft²		30.05
Option To Extend Lease Term	15 years			15 years

Unaudited Quarterly Statements of Operations Data (Detail) - USD ($)
$ / shares in Units, $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2016

Sep. 30, 2016

Jun. 30, 2016

Mar. 31, 2016

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Revenue

$ 66,763

$ 62,453

$ 63,348

$ 64,171

$ 62,647

$ 58,022

$ 57,874

$ 54,792

$ 256,735

$ 233,335

$ 185,143

Gross profit

33,503

31,986

34,520

32,570

30,125

28,910

28,124

25,495

132,579

112,654

82,292

Total operating expenses

37,285

35,601

35,996

37,215

35,189

35,434

37,215

36,984

146,097

144,822

136,566

Operating loss

(3,782)

(3,615)

(1,476)

(4,645)

(5,064)

(6,524)

(9,091)

(11,489)

(13,518)

(32,168)

(54,274)

Net loss

$ (7,004)

$ (6,674)

$ (4,506)

$ (7,688)

$ (7,099)

$ (8,603)

$ (11,004)

$ (13,352)

$ (25,872)

$ (40,058)

$ (62,084)

Basic and diluted

$ (0.22)

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$ (0.21)

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$ (0.14)

^[1]

$ (0.25)

^[1]

$ (0.24)

^[1]

$ (0.29)

^[1]

$ (0.37)

^[1]

$ (0.46)

^[1]

$ (0.83)

$ (1.35)

$ (2.19)

Weighted-average common shares outstanding, basic and diluted

31,285,263

31,181,141

31,076,995

30,658,468

30,030,164

29,651,230

29,459,341

29,213,198

31,052,378

29,589,857

28,344,680

[1]	Quarterly and year-to-date computations of per share amounts are made independently. Therefore, the sum of the per-share amounts for the quarters may not agree with per share amounts for the year.

Subsequent Events - Additional Information (Detail) - USD ($) $ in Thousands		1 Months Ended		2 Months Ended	12 Months Ended
	Mar. 15, 2018	Jan. 31, 2018	Feb. 28, 2015	Feb. 28, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Subsequent Event [Line Items]
Number of restricted stock units, granted					1,142,253
Payments on revolving line of credit					$ 89,000	$ 74,000	$ 44,903
Senior Revolving Line of Credit
Subsequent Event [Line Items]
Payments on revolving line of credit			$ 17,657
Restricted Stock Units (RSUs)
Subsequent Event [Line Items]
Vesting period of restricted stock awards					4 years
Subsequent Event
Subsequent Event [Line Items]
Issuance of common stock upon vesting of restricted stock units (in shares)				23,458
Subsequent Event \| Related Party Leasing Arrangements
Subsequent Event [Line Items]
Lease commencement date	Apr. 01, 2019
Term of extended lease commencement date	1 year
Extended lease commencement date	Jul. 01, 2020
Subsequent Event \| Senior Revolving Line of Credit
Subsequent Event [Line Items]
Payments on revolving line of credit		$ 24,000
Subsequent Event \| Restricted Stock Units (RSUs)
Subsequent Event [Line Items]
Number of restricted stock units, granted		54,040
Restricted stock units, aggregate grant date fair value		$ 1,446
Vesting period of restricted stock awards		4 years

Valuation and Qualifying Accounts (Detail) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Allowance for Doubtful Accounts

Valuation and Qualifying Accounts Disclosure [Line Items]

Balance at Beginning of Period

$ 4,595

$ 2,585

$ 1,663

Additions Charged To Expense

667

Additions Charged Against Revenue

5,343

5,004

7,646

Deductions

(6,547)

(3,661)

(6,746)

Balance at End of Period

3,466

4,595

2,585

Deferred tax asset valuation allowance

Valuation and Qualifying Accounts Disclosure [Line Items]

Balance at Beginning of Period

103,209

85,315

58,850

Additions Charged To Costs and Expenses

^[1]

32,113

17,894

26,465

Deductions

^[2]

(37,561)

Balance at End of Period

$ 97,761

$ 103,209

$ 85,315

[1]	) Increase in valuation allowance is related to the generation of net operating losses and other deferred tax assets.
[2]	Decrease in valuation on allowance is related to the change in the enacted tax rule.

Organization and Description of Business	12 Months Ended
Organization and Description of Business	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Benefitfocus, Inc. (the “Company”) provides a leading cloud-based benefits management platform for consumers, employers, insurance carriers and brokers under a software-as-a-service (“SaaS”) model. The financial statements of the Company include the financial position and operations of its wholly owned subsidiaries, Benefitfocus.com, Inc. and BenefitStore, Inc.