Document_and_Entity_Informatio
| Document and Entity Information | 3 Months Ended | |
| Mar. 31, 2014 | Apr. 16, 2014 | |
| Document And Entity Information [Abstract] | ' | ' |
| Document Type | '10-Q | ' |
| Amendment Flag | 'false | ' |
| Document Period End Date | 31-Mar-14 | ' |
| Document Fiscal Year Focus | '2014 | ' |
| Document Fiscal Period Focus | 'Q1 | ' |
| Trading Symbol | 'ATHN | ' |
| Entity Registrant Name | 'ATHENAHEALTH INC | ' |
| Entity Central Index Key | '0001131096 | ' |
| Current Fiscal Year End Date | '--12-31 | ' |
| Entity Filer Category | 'Large Accelerated Filer | ' |
| Entity Common Stock, Shares Outstanding | ' | 37,841,937 |
Condensed_Consolidated_Balance
| Condensed Consolidated Balance Sheets (USD $) | Mar. 31, 2014 | Dec. 31, 2013 |
| In Thousands, unless otherwise specified | ||
| Current assets: | ' | ' |
| Cash and cash equivalents | $51,263 | $65,002 |
| Marketable securities | 74,270 | 0 |
| Accounts receivable, net | 87,018 | 87,343 |
| Restricted cash | 194 | 3,000 |
| Deferred tax assets | 123 | 6,118 |
| Prepaid expenses and other current assets | 18,531 | 17,194 |
| Total current assets | 231,399 | 178,657 |
| Property and equipment, net | 212,338 | 213,018 |
| Capitalized software costs, net | 35,625 | 29,987 |
| Purchased intangible assets, net | 161,172 | 168,364 |
| Goodwill | 198,049 | 198,049 |
| Investments and other assets | 8,229 | 8,321 |
| Total assets | 846,812 | 796,396 |
| Current liabilities: | ' | ' |
| Accounts payable | 8,517 | 3,930 |
| Accrued compensation | 33,087 | 44,444 |
| Accrued expenses | 27,328 | 24,380 |
| Line of credit | 35,000 | 35,000 |
| Long-term debt | 15,000 | 15,000 |
| Deferred revenue | 28,843 | 27,002 |
| Deferred tax liability | 13,933 | 0 |
| Total current liabilities | 161,708 | 149,756 |
| Deferred rent, net of current portion | 1,829 | 1,478 |
| Long-term debt, net of current portion | 170,000 | 173,750 |
| Deferred revenue, net of current portion | 52,586 | 53,172 |
| Long-term deferred tax liability, net | 24,430 | 21,421 |
| Other long-term liabilities | 6,861 | 5,511 |
| Total liabilities | 417,414 | 405,088 |
| Commitments and contingencies (Note 6) | ' | ' |
| Stockholders’ equity: | ' | ' |
| Preferred stock, $0.01 par value: 5,000 shares authorized; no shares issued and outstanding at March 31, 2014 and December 31, 2013, respectively | 0 | 0 |
| Common stock, $0.01 par value: 125,000 shares authorized; 38,993 shares issued and 37,715 shares outstanding at March 31, 2014; 38,600 shares issued and 37,322 shares outstanding at December 31, 2013 | 390 | 387 |
| Additional paid-in capital | 381,358 | 380,967 |
| Treasury stock, at cost, 1,278 shares | -1,200 | -1,200 |
| Accumulated other comprehensive income (loss) | 45,305 | -446 |
| Retained earnings | 3,545 | 11,600 |
| Total stockholders’ equity | 429,398 | 391,308 |
| Total liabilities and stockholders’ equity | $846,812 | $796,396 |
Condensed_Consolidated_Balance1
| Condensed Consolidated Balance Sheets (Parenthetical) (USD $) | Mar. 31, 2014 | Dec. 31, 2013 |
| Preferred stock, par value (dollars per share) | $0.01 | $0.01 |
| Preferred stock, shares authorized (shares) | 5,000,000 | 5,000,000 |
| Preferred stock, shares issued (shares) | 0 | 0 |
| Preferred stock, shares outstanding (shares) | 0 | 0 |
| Common stock, par value (dollars per share) | $0.01 | $0.01 |
| Common stock, shares authorized (shares) | 125,000,000 | 125,000,000 |
| Common stock, shares issued (shares) | 38,993,000 | 38,600,000 |
| Common stock, shares outstanding (shares) | 37,715,000 | 37,322,000 |
| Treasury stock, shares (shares) | 1,278,000 | 1,278,000 |
Condensed_Consolidated_Stateme
| Condensed Consolidated Statements of Operations (USD $) | 3 Months Ended | |
| In Thousands, except Per Share data, unless otherwise specified | Mar. 31, 2014 | Mar. 31, 2013 |
| Revenue: | ' | ' |
| Business services | $154,502 | $121,463 |
| Implementation and other | 8,533 | 4,133 |
| Total revenue | 163,035 | 125,596 |
| Expense: | ' | ' |
| Direct operating | 72,148 | 53,185 |
| Selling and marketing | 43,227 | 32,922 |
| Research and development | 15,155 | 11,944 |
| General and administrative | 29,357 | 31,077 |
| Depreciation and amortization | 14,249 | 8,341 |
| Total expense | 174,136 | 137,469 |
| Operating loss | -11,101 | -11,873 |
| Other (expense) income: | ' | ' |
| Interest expense | -1,265 | -164 |
| Other (expense) income | -171 | 54 |
| Total other expense | -1,436 | -110 |
| Loss before income tax benefit | -12,537 | -11,983 |
| Income tax benefit (provision) | 4,482 | 12,683 |
| Net (loss) income | ($8,055) | $700 |
| Net (loss) income per share - Basic (in dollars per share) | ($0.21) | $0.02 |
| Net (loss) income per share - Diluted (in dollars per share) | ($0.21) | $0.02 |
| Weighted average shares used in computing net (loss) income per share: | ' | ' |
| Basic (shares) | 37,484 | 36,409 |
| Diluted (shares) | 37,484 | 37,744 |
Condensed_Consolidated_Stateme1
| Condensed Consolidated Statements of Comprehensive Income (USD $) | 3 Months Ended | |
| In Thousands, unless otherwise specified | Mar. 31, 2014 | Mar. 31, 2013 |
| Net (loss) income | ($8,055) | $700 |
| Other comprehensive income (loss) | ' | ' |
| Unrealized gain (loss) on securities, net of tax of $27,534 and $0 for the three months ended March 31, 2014 and 2013, respectively | 45,636 | -20 |
| Unrealized loss on interest rate derivative, net of tax of $8 and $0 for the three months ended March 31, 2014 and 2013, respectively | 12 | 0 |
| Foreign currency translation adjustment | 103 | -36 |
| Total other comprehensive income (loss) | 45,751 | -56 |
| Comprehensive income | $37,696 | $644 |
Condensed_Consolidated_Stateme2
| Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) | 3 Months Ended | |
| In Thousands, unless otherwise specified | Mar. 31, 2014 | Mar. 31, 2013 |
| Unrealized gain (loss) on securities, tax | $27,534 | $0 |
| Unrealized loss on interest rate derivative, tax | $8 | $0 |
Condensed_Consolidated_Stateme3
| Condensed Consolidated Statements of Cash Flows (USD $) | 3 Months Ended | |
| In Thousands, unless otherwise specified | Mar. 31, 2014 | Mar. 31, 2013 |
| CASH FLOWS FROM OPERATING ACTIVITIES: | ' | ' |
| Net (loss) income | ($8,055) | $700 |
| Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities: | ' | ' |
| Depreciation and amortization | 21,459 | 10,138 |
| Amortization of premium on investments | 0 | 84 |
| Deferred income tax | -4,605 | -12,745 |
| Stock-based compensation expense | 12,351 | 13,658 |
| Other reconciling adjustments | 171 | -6 |
| Changes in operating assets and liabilities: | ' | ' |
| Accounts receivable, net | 325 | -7,512 |
| Prepaid expenses and other current assets | -1,627 | -2,260 |
| Other long-term assets | -945 | 73 |
| Accounts payable | 3,913 | 1,985 |
| Accrued expenses | 2,951 | 4,199 |
| Accrued compensation | -13,529 | -15,640 |
| Deferred revenue | 1,255 | 2,095 |
| Deferred rent | 402 | -309 |
| Net cash provided by (used in) operating activities | 14,066 | -5,540 |
| CASH FLOWS FROM INVESTING ACTIVITIES: | ' | ' |
| Capitalized software development costs | -11,057 | -4,799 |
| Purchases of property and equipment | -5,325 | -11,003 |
| Proceeds from sales and maturities of investments | 0 | 56,245 |
| Payments on acquisitions, net of cash acquired | 0 | -242,836 |
| Change in restricted cash | 2,806 | 0 |
| Net cash used in investing activities | -13,576 | -202,393 |
| CASH FLOWS FROM FINANCING ACTIVITIES: | ' | ' |
| Proceeds from issuance of common stock under stock plans and warrants | 9,000 | 8,945 |
| Taxes paid related to net share settlement of stock awards | -19,464 | -7,199 |
| Proceeds from line of credit | 0 | 105,000 |
| Payments on long-term debt | -3,750 | 0 |
| Net settlement of acquired company’s board of directors equity shares | 0 | -5,806 |
| Debt issuance costs | 0 | -275 |
| Net cash (used in) provided by financing activities | -14,214 | 100,665 |
| Effects of exchange rate changes on cash and cash equivalents | -15 | 87 |
| Net decrease in cash and cash equivalents | -13,739 | -107,181 |
| Cash and cash equivalents at beginning of period | 65,002 | 154,988 |
| Cash and cash equivalents at end of period | 51,263 | 47,807 |
| Non-cash transactions | ' | ' |
| Property, equipment and purchased software recorded in accounts payable and accrued expenses | 3,753 | 890 |
| Fair value of equity awards assumed | 0 | 13,028 |
| Taxes to be paid related to net share settlement of stock units in accrued compensation | 2,209 | 0 |
| Additional disclosures | ' | ' |
| Cash paid for interest | 1,474 | 0 |
| Cash (refunded) paid for taxes | ($761) | $30 |
BASIS_OF_PRESENTATION
| BASIS OF PRESENTATION | 3 Months Ended |
| Mar. 31, 2014 | |
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | ' |
| BASIS OF PRESENTATION | ' |
| BASIS OF PRESENTATION | |
| General – The accompanying unaudited condensed consolidated financial statements have been prepared by athenahealth, Inc. (the “Company” or “we”) in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting and as required by Regulation S-X, Rule 10-01. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of the Company’s management, the accompanying unaudited condensed consolidated financial statements contain all adjustments (consisting of items of a normal and recurring nature) necessary to present fairly the financial position as of March 31, 2014 and the results of operations and cash flows for the three month periods ended March 31, 2014 and 2013. The results of operations for the three month period ended March 31, 2014 are not necessarily indicative of the results to be expected for the full year. When preparing financial statements in conformity with GAAP, we must make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates, and such differences could be material. | |
| We consider events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated through the date of issuance of these financial statements. | |
| Interim Tax Estimate – Because a relatively small change in our projected pre-tax net income (loss) could result in a volatile effective tax rate, we have used a discrete tax approach in calculating the tax benefit for the three months ended March 31, 2014. Under the discrete method, we determine our tax (expense) benefit based upon actual results as if the interim period was an annual period. | |
| Related Party Transaction – During the year ended December 31, 2013, we made a long-term investment in a vendor. The total expense for the three months ended March 31, 2014 was $1.3 million and the total amount payable at March 31, 2014 and December 31, 2013 was $0.6 million and $0.4 million, respectively. | |
| Business Combinations – On May 10, 2013, we completed the acquisition of the real estate commonly known as the Arsenal on the Charles, located in Watertown, Massachusetts. The fair value of the consideration paid was $167.3 million, which was based on management’s estimates and assumptions based on the information that was available as of the date of the acquisition. Certain items, such as the working capital adjustments to the purchase price, were subject to change as additional information was received about facts and circumstances that existed at the date of acquisition. During the three months ended March 31, 2014, we finalized this valuation. |
NET_INCOME_PER_SHARE
| NET INCOME PER SHARE | 3 Months Ended | ||||||||
| Mar. 31, 2014 | |||||||||
| Earnings Per Share [Abstract] | ' | ||||||||
| NET (LOSS) INCOME PER SHARE | ' | ||||||||
| NET (LOSS) INCOME PER SHARE | |||||||||
| Basic net income per share is computed by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per share is computed by dividing net income by the weighted average number of common shares outstanding and potentially dilutive securities outstanding during the period under the treasury stock method. Potentially dilutive securities include stock options, stock units, and shares to be purchased under the employee stock purchase plan. Under the treasury stock method, dilutive securities are assumed to be exercised at the beginning of the periods and as if funds obtained thereby were used to purchase common stock at the average market price during the period. Securities are excluded from the computations of diluted net income per share if their effect would be anti-dilutive to earnings per share. | |||||||||
| The following table reconciles the weighted average shares outstanding for basic and diluted net income per share for the periods indicated: | |||||||||
| Three Months Ended March 31, | |||||||||
| 2014 | 2013 | ||||||||
| Net (loss) income | $ | (8,055 | ) | $ | 700 | ||||
| Weighted average shares used in computing basic net (loss) income per share | 37,484 | 36,409 | |||||||
| Net (loss) income per share – basic | $ | (0.21 | ) | $ | 0.02 | ||||
| Net (loss) income | $ | (8,055 | ) | $ | 700 | ||||
| Weighted average shares used in computing basic net (loss) income per share | 37,484 | 36,409 | |||||||
| Effect of dilutive securities | — | 1,335 | |||||||
| Weighted average shares used in computing diluted net (loss) income per share | 37,484 | 37,744 | |||||||
| Net (loss) income per share – diluted | $ | (0.21 | ) | $ | 0.02 | ||||
| The computation of diluted net income per share excludes 0.8 million of stock options and stock units for the three months ended March 31, 2013 because their inclusion would have an anti-dilutive effect on net income per share. | |||||||||
FAIR_VALUE_OF_FINANCIAL_INSTRU
| FAIR VALUE OF FINANCIAL INSTRUMENTS | 3 Months Ended | ||||||||||||||||
| Mar. 31, 2014 | |||||||||||||||||
| Fair Value Disclosures [Abstract] | ' | ||||||||||||||||
| FAIR VALUE OF FINANCIAL INSTRUMENTS | ' | ||||||||||||||||
| FAIR VALUE OF FINANCIAL INSTRUMENTS | |||||||||||||||||
| As of March 31, 2014 and December 31, 2013, the carrying amounts of cash and cash equivalents, restricted cash, receivables, accounts payable and accrued expenses approximated their estimated fair values because of the short-term nature of these financial instruments. Included in cash and cash equivalents as of March 31, 2014 and December 31, 2013 are money market fund investments of less than $0.1 million, which are reported at fair value. As of March 31, 2014, we had $185.0 million outstanding on our term loan facility and $35.0 million outstanding on our revolving credit facility. As of December 31, 2013, we had $188.8 million outstanding on our term loan facility and $35.0 million outstanding on our revolving credit facility. The carrying amounts for these facilities approximate their fair values due to the nature of variable rate instruments which use current market rates. | |||||||||||||||||
| We previously invested a total of $1.1 million in a privately-held entity, Castlight Health, Inc. (“Castlight”), a leading provider of cloud-based software that enables enterprises to control health care costs. This investment was initially recorded and subsequently carried at cost through December 31, 2013. On March 14, 2014, an initial public offering (“IPO”) of shares of Castlight’s Class B common stock was made available for sale on the New York Stock Exchange under the symbol “CSLT.” As a result of the IPO, we classified this investment as “available-for-sale” and marked the shares we hold to market based on quoted market prices as of March 31, 2014. Although the investment is classified as available-for-sale, we are prohibited from selling the investment for 180 days subsequent to the IPO. As of March 31, 2014, the aggregate fair value of the investment was $74.3 million and is recorded in the Marketable securities line on the Condensed Consolidated Balance Sheet. The unrealized gain on investment of $45.6 million is included in other comprehensive income, net of a $27.5 million short-term deferred tax liability. | |||||||||||||||||
| Our interest rate swap agreement was designed to manage exposure to interest rates on our variable rate indebtedness. We recognize all derivatives on the Condensed Consolidated Balance Sheet at fair value. For the three months ended March 31, 2014, no amount was recognized in earnings for our interest rate swap. We do not expect that any of the approximately $0.2 million of net pre-tax derivative losses included in accumulated other comprehensive income (loss) at March 31, 2014 will be reclassified into earnings within the next 12 months. This amount will vary due to fluctuations in interest rates. There was no ineffectiveness associated with the interest rate swap during the three months ended March 31, 2014, nor was any amount excluded from ineffectiveness testing. We are exposed to credit loss in the event of non-performance by the swap counter party. | |||||||||||||||||
| The following table presents information about our financial assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2014 and December 31, 2013, and indicates the fair value hierarchy of the valuation techniques we utilized to determine such fair value. In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities, and fair values determined by Level 2 inputs utilize quoted prices (unadjusted) in inactive markets for identical assets or liabilities obtained from readily available pricing sources for similar instruments. The fair values determined by Level 3 inputs are unobservable values which are supported by little or no market activity. | |||||||||||||||||
| Fair Value Measurements as of March 31, 2014, Using | |||||||||||||||||
| Level 1 | Level 2 | Level 3 | Total | ||||||||||||||
| Cash and cash equivalents: | |||||||||||||||||
| Money market | $ | 30 | $ | — | $ | — | $ | 30 | |||||||||
| Available-for-sale investments: | |||||||||||||||||
| Marketable equity securities | 74,270 | — | — | 74,270 | |||||||||||||
| Total assets | $ | 74,300 | $ | — | $ | — | $ | 74,300 | |||||||||
| Interest rate swap liability (a) | $ | — | $ | (334 | ) | $ | — | $ | (334 | ) | |||||||
| Total liabilities | $ | — | $ | (334 | ) | $ | — | $ | (334 | ) | |||||||
| Fair Value Measurements as of December 31, 2013, Using | |||||||||||||||||
| Level 1 | Level 2 | Level 3 | Total | ||||||||||||||
| Cash and cash equivalents: | |||||||||||||||||
| Money market | $ | 26 | $ | — | $ | — | $ | 26 | |||||||||
| Total assets | $ | 26 | $ | — | $ | — | $ | 26 | |||||||||
| Interest rate swap liability (a) | $ | — | $ | (354 | ) | $ | — | $ | (354 | ) | |||||||
| Total liabilities | $ | — | $ | (354 | ) | $ | — | $ | (354 | ) | |||||||
| (a) | Recorded in other long-term liabilities on the Condensed Consolidated Balance Sheets. | ||||||||||||||||
| Money market funds and marketable equity securities are valued using a market approach based upon the quoted market prices of identical instruments when available or other observable inputs such as trading prices of identical instruments in inactive markets or similar securities. It is our policy to recognize transfers between levels of the fair value hierarchy, if any, at the end of the reporting period; however, there have been no such transfers during any periods presented. | |||||||||||||||||
| The estimated fair value of our interest rate swap agreement with a certain financial institution at March 31, 2014 was $0.3 million, based on inputs other than quoted prices that are observable for the interest rate swap (Level 2). Inputs include preset value of fixed and projected floating rate cash flows over term of the swap contract. | |||||||||||||||||
INVESTMENTS
| INVESTMENTS | 3 Months Ended | ||||||||||||
| Mar. 31, 2014 | |||||||||||||
| Investments [Abstract] | ' | ||||||||||||
| INVESTMENTS | ' | ||||||||||||
| INVESTMENTS | |||||||||||||
| We had the following available-for-sale securities at March 31, 2014: | |||||||||||||
| Cost | Gross | Fair Value | |||||||||||
| Unrealized Gain | |||||||||||||
| Marketable equity securities | $ | 1,100 | $ | 73,170 | $ | 74,270 | |||||||
| As of December 31, 2013, we had no available-for-sale securities. | |||||||||||||
OPERATING_LEASES
| OPERATING LEASES | 3 Months Ended | |||
| Mar. 31, 2014 | ||||
| Leases [Abstract] | ' | |||
| OPERATING LEASES | ' | |||
| OPERATING LEASES | ||||
| Future minimum lease payments under non-cancelable operating leases as of March 31, 2014 are as follows: | ||||
| Year ending December 31, | Future Rent | |||
| Payments | ||||
| Remaining 2014 | $ | 5,344 | ||
| 2015 | 8,551 | |||
| 2016 | 10,563 | |||
| 2017 | 11,139 | |||
| 2018 | 11,455 | |||
| Thereafter | 91,784 | |||
| $ | 138,836 | |||
COMMITMENTS_AND_CONTINGENCIES
| COMMITMENTS AND CONTINGENCIES | 3 Months Ended |
| Mar. 31, 2014 | |
| Commitments and Contingencies Disclosure [Abstract] | ' |
| COMMITMENTS AND CONTINGENCIES | ' |
| COMMITMENTS AND CONTINGENCIES | |
| We are engaged from time to time in certain legal disputes arising in the ordinary course of business, including employment discrimination claims and challenges to our intellectual property. We believe that we have adequate legal defenses and that the likelihood of a loss contingency relating to the ultimate dispositions of any of these disputes is remote. When the likelihood of a loss contingency becomes at least reasonably possible with respect to any of these disputes, or, as applicable in the future, if there is at least a reasonable possibility that a loss exceeding amounts already recognized may have been incurred, we will revise our disclosures in accordance with the relevant authoritative guidance. | |
| Additionally, we will accrue a liability for loss contingencies when we believe that it is both probable that a liability has been incurred and that we can reasonably estimate the amount of the loss. We will review these accruals and adjust them to reflect ongoing negotiations, settlements, rulings, advice of legal counsel, and other relevant information. To the extent new information is obtained, and our views on the probable outcomes of claims, suits, assessments, investigations, or legal proceedings change, changes in our accrued liabilities would be recorded in the period in which such determination is made. |
BASIS_OF_PRESENTATION_Policies
| BASIS OF PRESENTATION (Policies) | 3 Months Ended |
| Mar. 31, 2014 | |
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | ' |
| Interim Tax Estimate | ' |
| Interim Tax Estimate – Because a relatively small change in our projected pre-tax net income (loss) could result in a volatile effective tax rate, we have used a discrete tax approach in calculating the tax benefit for the three months ended March 31, 2014. Under the discrete method, we determine our tax (expense) benefit based upon actual results as if the interim period was an annual period. | |
| Business Combinations | ' |
| Business Combinations – On May 10, 2013, we completed the acquisition of the real estate commonly known as the Arsenal on the Charles, located in Watertown, Massachusetts. The fair value of the consideration paid was $167.3 million, which was based on management’s estimates and assumptions based on the information that was available as of the date of the acquisition. Certain items, such as the working capital adjustments to the purchase price, were subject to change as additional information was received about facts and circumstances that existed at the date of acquisition. During the three months ended March 31, 2014, we finalized this valuation. |
NET_INCOME_PER_SHARE_Tables
| NET INCOME PER SHARE (Tables) | 3 Months Ended | ||||||||
| Mar. 31, 2014 | |||||||||
| Earnings Per Share [Abstract] | ' | ||||||||
| Schedule of Earnings Per Share, Basic and Diluted | ' | ||||||||
| The following table reconciles the weighted average shares outstanding for basic and diluted net income per share for the periods indicated: | |||||||||
| Three Months Ended March 31, | |||||||||
| 2014 | 2013 | ||||||||
| Net (loss) income | $ | (8,055 | ) | $ | 700 | ||||
| Weighted average shares used in computing basic net (loss) income per share | 37,484 | 36,409 | |||||||
| Net (loss) income per share – basic | $ | (0.21 | ) | $ | 0.02 | ||||
| Net (loss) income | $ | (8,055 | ) | $ | 700 | ||||
| Weighted average shares used in computing basic net (loss) income per share | 37,484 | 36,409 | |||||||
| Effect of dilutive securities | — | 1,335 | |||||||
| Weighted average shares used in computing diluted net (loss) income per share | 37,484 | 37,744 | |||||||
| Net (loss) income per share – diluted | $ | (0.21 | ) | $ | 0.02 | ||||
FAIR_VALUE_OF_FINANCIAL_INSTRU1
| FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables) | 3 Months Ended | ||||||||||||||||
| Mar. 31, 2014 | |||||||||||||||||
| Fair Value Disclosures [Abstract] | ' | ||||||||||||||||
| Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis | ' | ||||||||||||||||
| The following table presents information about our financial assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2014 and December 31, 2013, and indicates the fair value hierarchy of the valuation techniques we utilized to determine such fair value. In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities, and fair values determined by Level 2 inputs utilize quoted prices (unadjusted) in inactive markets for identical assets or liabilities obtained from readily available pricing sources for similar instruments. The fair values determined by Level 3 inputs are unobservable values which are supported by little or no market activity. | |||||||||||||||||
| Fair Value Measurements as of March 31, 2014, Using | |||||||||||||||||
| Level 1 | Level 2 | Level 3 | Total | ||||||||||||||
| Cash and cash equivalents: | |||||||||||||||||
| Money market | $ | 30 | $ | — | $ | — | $ | 30 | |||||||||
| Available-for-sale investments: | |||||||||||||||||
| Marketable equity securities | 74,270 | — | — | 74,270 | |||||||||||||
| Total assets | $ | 74,300 | $ | — | $ | — | $ | 74,300 | |||||||||
| Interest rate swap liability (a) | $ | — | $ | (334 | ) | $ | — | $ | (334 | ) | |||||||
| Total liabilities | $ | — | $ | (334 | ) | $ | — | $ | (334 | ) | |||||||
| Fair Value Measurements as of December 31, 2013, Using | |||||||||||||||||
| Level 1 | Level 2 | Level 3 | Total | ||||||||||||||
| Cash and cash equivalents: | |||||||||||||||||
| Money market | $ | 26 | $ | — | $ | — | $ | 26 | |||||||||
| Total assets | $ | 26 | $ | — | $ | — | $ | 26 | |||||||||
| Interest rate swap liability (a) | $ | — | $ | (354 | ) | $ | — | $ | (354 | ) | |||||||
| Total liabilities | $ | — | $ | (354 | ) | $ | — | $ | (354 | ) | |||||||
| (a) | Recorded in other long-term liabilities on the Condensed Consolidated Balance Sheets. | ||||||||||||||||
INVESTMENTS_Tables
| INVESTMENTS (Tables) | 3 Months Ended | ||||||||||||
| Mar. 31, 2014 | |||||||||||||
| Investments [Abstract] | ' | ||||||||||||
| Schedule of Available-for-sale Securities Reconciliation | ' | ||||||||||||
| We had the following available-for-sale securities at March 31, 2014: | |||||||||||||
| Cost | Gross | Fair Value | |||||||||||
| Unrealized Gain | |||||||||||||
| Marketable equity securities | $ | 1,100 | $ | 73,170 | $ | 74,270 | |||||||
OPERATING_LEASES_Tables
| OPERATING LEASES (Tables) | 3 Months Ended | |||
| Mar. 31, 2014 | ||||
| Leases [Abstract] | ' | |||
| Schedule of Future Minimum Rental Payments for Operating Leases | ' | |||
| Future minimum lease payments under non-cancelable operating leases as of March 31, 2014 are as follows: | ||||
| Year ending December 31, | Future Rent | |||
| Payments | ||||
| Remaining 2014 | $ | 5,344 | ||
| 2015 | 8,551 | |||
| 2016 | 10,563 | |||
| 2017 | 11,139 | |||
| 2018 | 11,455 | |||
| Thereafter | 91,784 | |||
| $ | 138,836 | |||
BASIS_OF_PRESENTATION_Addition
| BASIS OF PRESENTATION (Additional Information) (Detail) (USD $) | 3 Months Ended | 0 Months Ended | |
| In Millions, unless otherwise specified | Mar. 31, 2014 | Dec. 31, 2013 | 10-May-13 |
| Arsenal on the Charles | |||
| Significant Accounting Policies [Line Items] | ' | ' | ' |
| Total related party expense | $1.30 | ' | ' |
| Total amount payable to related parties | 0.6 | 0.4 | ' |
| Fair value of consideration paid | ' | ' | $167.30 |
NET_INCOME_PER_SHARE_Reconcili
| NET INCOME PER SHARE (Reconciliation of Weighted Average Shares Outstanding for Basic and Diluted Net Income Per Share) (Details) (USD $) | 3 Months Ended | |
| In Thousands, except Per Share data, unless otherwise specified | Mar. 31, 2014 | Mar. 31, 2013 |
| Earnings Per Share [Abstract] | ' | ' |
| Net (loss) income | ($8,055) | $700 |
| Weighted average shares used in computing basic net (loss) income per share (shares) | 37,484 | 36,409 |
| Net (loss) income per share - basic (in dollars per share) | ($0.21) | $0.02 |
| Effect of dilutive securities (shares) | 0 | 1,335 |
| Weighted average shares used in computing diluted net (loss) income per share (shares) | 37,484 | 37,744 |
| Net (loss) income per share - diluted (in dollars per share) | ($0.21) | $0.02 |
NET_INCOME_PER_SHARE_Net_Incom
| NET INCOME PER SHARE (Net Income Per Share - Additional Information) (Detail) | 3 Months Ended |
| In Millions, unless otherwise specified | Mar. 31, 2013 |
| Earnings Per Share [Abstract] | ' |
| Options and restricted stock units which have an antidilutive effect (shares) | 0.8 |
FAIR_VALUE_OF_FINANCIAL_INSTRU2
| FAIR VALUE OF FINANCIAL INSTRUMENTS (Fair Value of Financial Instruments - Additional Information) (Detail) (USD $) | 3 Months Ended | 3 Months Ended | |||||||||||||||||
| Mar. 31, 2014 | Mar. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | |||||
| Fair Value, Measurements, Recurring | Fair Value, Measurements, Recurring | Fair Value, Measurements, Recurring | Fair Value, Measurements, Recurring | Castlight Health, Inc. | Castlight Health, Inc. | Castlight Health, Inc. | Senior Credit Facility | Senior Credit Facility | Senior Credit Facility | Senior Credit Facility | Money market | Money market | |||||||
| Level 2 | Level 2 | Marketable Securities | Unsecured Debt | Unsecured Debt | Revolving Credit Facility | Revolving Credit Facility | |||||||||||||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ||||
| Cash and cash equivalents: | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $100,000 | $100,000 | ||||
| Amount outstanding on facility | ' | ' | ' | ' | ' | ' | ' | ' | ' | 185,000,000 | 188,800,000 | 35,000,000 | 35,000,000 | ' | ' | ||||
| Amount invested in privately held entity | ' | ' | ' | ' | ' | ' | ' | 1,100,000 | ' | ' | ' | ' | ' | ' | ' | ||||
| Period for which the Company is legally restricted from selling investment subsequent to IPO | ' | ' | ' | ' | ' | ' | '180 days | ' | ' | ' | ' | ' | ' | ' | ' | ||||
| Marketable securities | ' | ' | ' | ' | ' | ' | ' | ' | 74,300,000 | ' | ' | ' | ' | ' | ' | ||||
| Unrealized gain on investment | 45,636,000 | -20,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ||||
| Short term deferred tax liability | 27,534,000 | 0 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ||||
| Amount recognized in earnings | 0 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ||||
| Pre-tax derivative losses included in accumulated other comprehensive income (loss) | 200,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ||||
| Ineffectiveness associated with interest rate swap | 0 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ||||
| Long-term U.S. government backed securities | 0 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ||||
| Interest rate swap liability | ' | ' | ($334,000) | [1] | ($354,000) | [1] | ($334,000) | [1] | ($354,000) | [1] | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| [1] | Recorded in other long-term liabilities on the Condensed Consolidated Balance Sheets. | ||||||||||||||||||
FAIR_VALUE_OF_FINANCIAL_INSTRU3
| FAIR VALUE OF FINANCIAL INSTRUMENTS (Financial Assets and Liabilities that Are Measured at Fair Value on Recurring Basis) (Detail) (USD $) | Mar. 31, 2014 | Dec. 31, 2013 | ||
| In Thousands, unless otherwise specified | ||||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Available-for-sale investments: | ' | $0 | ||
| Fair Value, Measurements, Recurring | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Total assets | 74,300 | 26 | ||
| Interest rate swap liability | -334 | [1] | -354 | [1] |
| Total liabilities | -334 | -354 | ||
| Fair Value, Measurements, Recurring | Level 1 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Total assets | 74,300 | 26 | ||
| Interest rate swap liability | 0 | [1] | 0 | [1] |
| Total liabilities | 0 | 0 | ||
| Fair Value, Measurements, Recurring | Level 2 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Total assets | 0 | 0 | ||
| Interest rate swap liability | -334 | [1] | -354 | [1] |
| Total liabilities | -334 | -354 | ||
| Fair Value, Measurements, Recurring | Level 3 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Total assets | 0 | 0 | ||
| Interest rate swap liability | 0 | [1] | 0 | [1] |
| Total liabilities | 0 | 0 | ||
| Money market | Fair Value, Measurements, Recurring | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Cash and cash equivalents: | 30 | 26 | ||
| Money market | Fair Value, Measurements, Recurring | Level 1 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Cash and cash equivalents: | 30 | 26 | ||
| Money market | Fair Value, Measurements, Recurring | Level 2 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Cash and cash equivalents: | 0 | 0 | ||
| Money market | Fair Value, Measurements, Recurring | Level 3 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Cash and cash equivalents: | 0 | 0 | ||
| Marketable equity securities | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Available-for-sale investments: | 74,270 | ' | ||
| Marketable equity securities | Fair Value, Measurements, Recurring | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Available-for-sale investments: | 74,270 | ' | ||
| Marketable equity securities | Fair Value, Measurements, Recurring | Level 1 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Available-for-sale investments: | 74,270 | ' | ||
| Marketable equity securities | Fair Value, Measurements, Recurring | Level 2 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Available-for-sale investments: | 0 | ' | ||
| Marketable equity securities | Fair Value, Measurements, Recurring | Level 3 | ' | ' | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' | ||
| Available-for-sale investments: | $0 | ' | ||
| [1] | Recorded in other long-term liabilities on the Condensed Consolidated Balance Sheets. | |||
INVESTMENTS_Summary_of_Availab
| INVESTMENTS (Summary of Available-For-Sale Securities) (Details) (USD $) | Dec. 31, 2013 | Mar. 31, 2014 |
| In Thousands, unless otherwise specified | Marketable equity securities | |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Cost | ' | $1,100 |
| Gross Unrealized Gain | ' | 73,170 |
| Fair Value | $0 | $74,270 |
OPERATING_LEASES_Future_Minimu
| OPERATING LEASES (Future Minimum Lease Payments Under Non-cancelable Operating Leases) (Details) (USD $) | Mar. 31, 2014 |
| In Thousands, unless otherwise specified | |
| Leases [Abstract] | ' |
| Remaining 2014 | $5,344 |
| 2015 | 8,551 |
| 2016 | 10,563 |
| 2017 | 11,139 |
| 2018 | 11,455 |
| Thereafter | 91,784 |
| Total minimum lease payments | $138,836 |