Cornerstone OnDemand (CSOD) 10-K 26 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 21, 2014	Jun. 30, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'CSOD	'	'
Entity Registrant Name	'CORNERSTONE ONDEMAND INC	'	'
Entity Central Index Key	'0001401680	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	52,801,166	'
Entity Public Float	'	'	$1,462,792,729
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets	'	'
Cash and cash equivalents	$109,583	$76,442
Short-term investments	199,925	0
Accounts receivable, net	67,191	47,528
Deferred commissions	16,634	9,354
Prepaid expenses and other current assets	14,118	8,249
Total current assets	407,451	141,573
Capitalized software development costs, net	10,665	7,007
Property and equipment, net	14,436	7,947
Intangible assets, net	4,632	6,887
Goodwill	8,193	8,193
Other assets, net	5,978	227
Total Assets	451,355	171,834
Liabilities:	'	'
Accounts payable	10,037	4,849
Accrued expenses	22,288	14,986
Deferred revenue, current portion	135,322	87,759
Capital lease obligations, current portion	905	1,643
Debt, current portion	519	916
Other liabilities	4,203	3,885
Total current liabilities	173,274	114,038
Convertible notes, net	217,965	0
Other liabilities, non-current	3,111	3,592
Deferred revenue, net of current portion	3,500	4,493
Capital lease obligations, net of current portion	218	1,227
Debt, net of current portion	392	1,836
Total liabilities	398,460	125,186
Commitments and contingencies (Note 16)	'	'
Stockholders’ Equity:	'	'
Common stock, $0.0001 par value; 1,000,000 shares authorized, 52,470 and 50,690 shares issued and outstanding at December 31, 2013 and 2012	5	5
Additional paid-in capital	289,307	242,767
Accumulated deficit	-236,467	-196,041
Accumulated other comprehensive income (loss)	50	-83
Total stockholders’ equity	52,895	46,648
Total Liabilities and Stockholders’ Equity	$451,355	$171,834

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]	'	'
Common stock, par value (in usd per share)	$0.00	$0.00
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	52,470,000	50,689,000
Common stock, shares outstanding	52,470,000	50,689,000

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]	'	'	'
Revenue (net of a $2,500 reduction of revenue in 2011 relating to common stock warrants)	$185,129	$117,914	$73,022
Cost of revenue	53,548	34,591	21,285
Gross profit	131,581	83,323	51,737
Operating expenses:	'	'	'
Sales and marketing	109,737	73,563	45,773
Research and development	21,260	14,886	10,149
General and administrative	33,572	25,912	15,122
Amortization of certain acquired intangible assets	1,004	739	0
Total operating expenses	165,573	115,100	71,044
Loss from operations	-33,992	-31,777	-19,307
Other income (expense):	'	'	'
Interest income	357	0	20
Interest expense	-6,563	-442	-902
Change in fair value of preferred stock warrant liabilities	0	0	-42,559
Withdrawn secondary offering expense	0	0	-555
Other, net	-356	40	-416
Other income (expense), net	-6,562	-402	-44,412
Loss before income tax benefit (provision)	-40,554	-32,179	-63,719
Income tax benefit (provision)	128	789	-181
Net loss	-40,426	-31,390	-63,900
Accretion of redeemable preferred stock	0	0	-5,208
Net loss attributable to common stockholders	($40,426)	($31,390)	($69,108)
Net loss per share attributable to common stockholders, basic and diluted	($0.79)	($0.63)	($1.74)
Weighted average common shares outstanding, basic and diluted	51,427	49,929	39,824

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]	'	'	'
Reduction of revenue relating to common stock warrants	$0	$0	$2,500

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]	'	'	'
Net loss	($40,426)	($31,390)	($63,900)
Other comprehensive income (loss), net of tax:	'	'	'
Foreign currency translation adjustment	3	-273	217
Net change in unrealized gains (losses) on investments	130	0	0
Other comprehensive income (loss), net of tax	133	-273	217
Total comprehensive loss	($40,293)	($31,663)	($63,683)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock	Treasury Stock	Additional Paid-In Capital (Deficit)	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
In Thousands, except Share data
Beginning balance at Dec. 31, 2010	($97,231)	$1	$0	$597	($97,802)	($27)
Beginning balance (in shares) at Dec. 31, 2010	'	10,586,000	0	'	'	'
Accretion of preferred stock	-5,208	'	'	-2,259	-2,949	'
Conversion of preferred stock to common stock (in shares)	'	28,809,000	'	'	'	'
Conversion of preferred stock to common stock	132,775	3	'	132,772	'	'
Issuance of common stock for the exercise of warrants to purchase common stock (in shares)	'	898,000	'	'	'	'
Issuance of common stock for the exercise of warrants to purchase common stock	474	'	'	474	'	'
Issuance of common stock upon initial public offering, net of issuance costs (in shares)	'	7,500,000	'	'	'	'
Issuance of common stock upon initial public offering, net of issuance costs	86,853	1	'	86,852	'	'
Issuance of common stock to a non-profit organization (in shares)	'	20,000	'	'	'	'
Issuance of common stock to a non-profit organization	193	'	'	193	'	'
Issuance of common stock upon the exercise of options (in shares)	'	1,461,000	'	'	'	'
Issuance of common stock upon the exercise of options	1,017	'	'	1,017	'	'
Issuance of common stock warrants	2,500	'	'	2,500	'	'
Vesting of early exercised options	82	'	'	82	'	'
Tax withholding on net exercise of stock-based awards	-48	'	'	-48	'	'
Stock-based compensation	4,736	'	'	4,736	'	'
Net change in unrealized gains (losses) on investments	0	'	'	'	'	'
Net loss	-63,900	'	'	'	-63,900	'
Other comprehensive income (loss), net of tax	217	'	'	'	'	217
Ending balance at Dec. 31, 2011	62,460	5	0	226,916	-164,651	190
Ending balance (in shares) at Dec. 31, 2011	'	49,274,000	0	'	'	'
Issuance of common stock for the exercise of warrants to purchase common stock (in shares)	'	130,000	'	'	'	'
Issuance of common stock for the exercise of warrants to purchase common stock	208	'	'	208	'	'
Issuance of common stock upon the exercise of options (in shares)	'	1,127,000	'	'	'	'
Issuance of common stock upon the exercise of options	2,490	'	'	2,490	'	'
Vesting of early exercised options	55	'	'	55	'	'
Vesting of restricted stock units (in shares)	'	112,000	'	'	'	'
Vesting of restricted stock units	0	'	'	'	'	'
Shares issued for Sonar Limited (in shares)	'	47,000	'	'	'	'
Shares issued for acquisition of Sonar Limited	335	'	'	335	'	'
Stock-based compensation	12,763	'	'	12,763	'	'
Net change in unrealized gains (losses) on investments	0	'	'	'	'	'
Net loss	-31,390	'	'	'	-31,390	'
Other comprehensive income (loss), net of tax	-273	'	'	'	'	-273
Ending balance at Dec. 31, 2012	46,648	5	0	242,767	-196,041	-83
Ending balance (in shares) at Dec. 31, 2012	'	50,690,000	0	'	'	'
Issuance of common stock upon the exercise of options (in shares)	1,566,000	1,566,000	'	'	'	'
Issuance of common stock upon the exercise of options	13,432	'	'	13,432	'	'
Vesting of early exercised options	28	'	'	28	'	'
Vesting of restricted stock units (in shares)	'	214,000	'	'	'	'
Vesting of restricted stock units	0	'	'	'	'	'
Tax withholding on net exercise of stock-based awards	-29	'	'	-29	'	'
Stock-based compensation	21,769	'	'	21,769	'	'
Net change in unrealized gains (losses) on investments	130	'	'	'	'	130
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt	11,282	'	'	11,282	'	'
Net loss	-40,426	'	'	'	-40,426	'
Other comprehensive income (loss), net of tax	3	'	'	'	'	3
Ending balance at Dec. 31, 2013	$52,895	$5	$0	$289,307	($236,467)	$50
Ending balance (in shares) at Dec. 31, 2013	'	52,470,000	0	'	'	'

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:	'	'	'
Net loss	($40,426)	($31,390)	($63,900)
Adjustments to reconcile net loss to net cash provided by operating activities:	'	'	'
Depreciation and amortization	9,700	7,037	3,714
Accretion of debt discount and amortization of debt issuance costs	4,273	143	579
Purchased investment premium, net of amortization	-2,031	0	0
Change in fair value of preferred stock warrant liabilities	0	0	42,559
Unrealized foreign exchange loss (gain)	242	-182	460
Charges related to the issuance of common stock warrants to a distributor	0	0	2,500
Stock-based compensation expense	20,840	12,207	4,502
Withdrawn secondary offering expense	0	0	555
Non-cash charitable contribution of common stock	0	0	193
Deferred income taxes	-865	-965	0
Changes in operating assets and liabilities, net of effects from acquisition:	'	'	'
Accounts receivable	-19,046	-12,254	-13,308
Deferred commissions	-7,085	-5,691	-1,274
Prepaid expenses and other assets	-6,057	-4,188	-1,804
Accounts payable	5,082	190	915
Accrued expenses	6,828	6,325	3,314
Deferred revenue	45,230	35,327	22,161
Other liabilities	746	3,735	666
Net cash provided by operating activities	17,431	10,294	1,832
Cash flows from investing activities:	'	'	'
Purchases of investments	203,959	0	34,079
Maturities of investments	6,182	0	34,000
Purchases of property and equipment	-8,762	-2,123	-784
Capitalized software costs	-6,906	-5,030	-3,022
Cash paid for acquisition, net of cash acquired	0	-12,428	0
Net cash used in investing activities	-213,445	-19,581	-3,885
Cash flows from financing activities:	'	'	'
Proceeds from issuance of convertible notes, net	245,664	0	0
Payments for convertible note hedges	-49,537	0	0
Proceeds from the issuance of warrants	23,225	0	0
Proceeds from initial public offering, net of underwriting discounts and commissions	0	0	90,539
Payments of initial public offering costs	0	0	-3,436
Proceeds from issuance of preferred stock upon warrant exercises	0	0	3,163
Payments of withdrawn secondary offering costs	0	0	-555
Proceeds from the issuance of debt	1,914	1,043	669
Repayment of debt	-4,038	-1,510	-9,207
Principal payments under capital lease obligations	-1,747	-1,919	-1,977
Proceeds from stock option and warrant exercises	13,447	2,698	1,491
Payment of withholding tax on net exercise of stock-based awards	0	0	-48
Net cash provided by financing activities	228,928	312	80,639
Effect of exchange rate changes on cash and cash equivalents	227	8	-244
Net increase (decrease) in cash and cash equivalents	33,141	-8,967	78,342
Cash and cash equivalents at beginning of period	76,442	85,409	7,067
Cash and cash equivalents at end of period	109,583	76,442	85,409
Supplemental cash flow information:	'	'	'
Cash paid for interest	2,294	341	543
Cash paid for income taxes	485	103	104
Non-cash investing and financing activities:	'	'	'
Conversion of convertible preferred stock to common stock	0	0	132,775
Assets acquired under capital leases and other financing arrangements	88	3,722	1,131
Common stock issued for business acquisition	0	335	0
Capitalized assets financed by accounts payable and accrued expenses	1,175	693	25
Capitalized stock-based compensation	$941	$556	$234

Organization

Organization	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization	'
	ORGANIZATION
	Company Overview
	Cornerstone OnDemand, Inc. (“Cornerstone” or the “Company”) was incorporated on May 24, 1999 in the state of Delaware and began its principal operations in November 1999.
	The Company is a leading global provider of comprehensive talent management solutions delivered as Software-as-a-Service (“SaaS”). The Company’s core solution consists of four integrated clouds for recruiting, learning management, performance management and extended enterprise. Customers may subscribe to one or more of the clouds.
	The Company’s solutions are designed to enable organizations to meet the challenges they face in empowering and maximizing the productivity of their human capital. These challenges include hiring and developing employees throughout their careers, engaging all employees effectively, improving business execution, cultivating future leaders, and integrating with an organization’s extended enterprise of clients, vendors and distributors by delivering training, certification programs and other content. Management has determined that it operates in one segment as it only reports financial information on an aggregate and consolidated basis to its chief executive officer, who is the Company’s chief operating decision maker.
	The Company also offers Cornerstone Small Business, a talent management solution for small businesses and Cornerstone for Salesforce, a cloud-based talent management solution developed on the Salesforce.com platform which allows organizations to provide access to sales enablement and just-in-time training from within Salesforce.
	Office Locations
	The Company is headquartered in Santa Monica, California and has offices in Auckland, Hong Kong, London, Madrid, Mumbai, Munich, Paris, Rome, Sydney, Tel Aviv, and Tokyo.

Summary_of_Significant_Account

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

'

Summary of Significant Accounting Policies

'

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Consolidation

The accompanying consolidated financial statements include the accounts of Cornerstone OnDemand, Inc., and its wholly owned subsidiaries. All significant inter-company transactions and balances have been eliminated in consolidation.

Use of Estimates

The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.

On an on-going basis, management evaluates its estimates, including among others those related to: (i) the realization of tax assets and estimates of tax liabilities, (ii) the recognition and disclosure of contingent liabilities, (iii) the collectability of accounts receivable, (iv) the evaluation of revenue recognition criteria, including the determination of standalone value and estimates of the selling price of multiple-deliverables in the Company’s revenue arrangements, (v) fair values of investments in marketable securities, (vi) the assigned value of acquired assets and assumed liabilities in business combinations, (vii) the useful lives of property and equipment, capitalized software and intangible assets, (viii) impairment of long-lived assets, including goodwill, (ix) the amount and period of amortization of the commission payments to record to expense in proportion to the revenue that is recognized, and (x) assumptions used in the Black-Scholes option pricing model to determine the fair value of stock options and warrants. These estimates are based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. The Company engages third-party valuation specialists to assist with the allocation of the purchase price in business combinations and, prior to the Company's IPO in March 2011, the Company engaged third-party valuation specialists to assist with estimates related to the valuation of its preferred and common stock. Such estimates required the selection of appropriate valuation methodologies and models, and significant judgment in evaluating ranges of assumptions and financial inputs.

Withdrawn Secondary Offering

On July 20, 2011, in connection with a proposed secondary offering of shares of common stock by the Company and certain existing stockholders (“the secondary offering”), the Company filed a Registration Statement on Form S-1 with the Securities and Exchange Commission (“SEC”). On August 8, 2011, pursuant to Rule 477 promulgated under the Securities Act of 1933, as amended, the Company requested that the SEC consent to the withdrawal of the Registration Statement, including all amendments and exhibits. During the year ended December 31, 2011, the Company incurred expenses of approximately $0.6 million in connection with the proposed secondary offering which were recorded in other, net, within other income (expense) in the Company’s statements of operations.

Reclassifications

Certain amounts in the consolidated cash flows at December 31, 2012 have been reclassified to conform to the current year presentation.

Business Combinations

The results of businesses acquired in a business combination are included in the Company’s consolidated financial statements from the date of the acquisition. Purchase accounting results in assets and liabilities of an acquired business being recorded at their estimated fair values on the acquisition date. Any excess consideration over the fair value of assets acquired and liabilities assumed is recognized as goodwill.

The Company performs valuations of assets acquired and liabilities assumed for an acquisition and allocates the purchase price to its respective net tangible and intangible assets. Determining the fair value of assets acquired and liabilities assumed requires management to use significant judgment and estimates including the selection of valuation methodologies, estimates of future revenue and cash flows, discount rates and selection of comparable companies. The Company engages the assistance of valuation specialists in concluding on fair value measurements in connection with fair values of assets and liabilities assumed in a business combination.

Transaction costs associated with business combinations are expensed as incurred, and are included in general and administrative expenses in the consolidated statement of operations. There were no transaction costs for the year ended December 31, 2013. Transaction costs were $0.7 million for the year ended December 31, 2012.

Net Loss per Share Attributable to Common Stockholders

Basic net loss per share of common stock is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for a period.

Prior to the Company’s IPO in March 2011, as the Company had convertible preferred stock outstanding, and, as the holders of the Company’s convertible preferred stock were entitled to participate in dividends and earnings of the Company, the Company used the two-class method in calculating earnings per share for periods in which the Company generated net income. As the holders of the Company’s convertible preferred stock were not contractually obligated to share in the losses of the Company, no such allocation was made for any periods presented given the Company’s net losses.

The Company may grant restricted stock under the 2010 Equity Incentive Plan (“2010 Plan”) (See Note 12). As the holders of the Company’s restricted stock under the 2010 Plan are both entitled to participate in dividends and earnings of the Company, the Company uses the two-class method in calculating earnings per share for periods in which the Company generates income. As restricted stock holders are not contractually obligated to share in the losses, no such allocation was made for any periods presented given the company’s net losses.

The two-class method requires net income to be allocated between the classes of stockholders, whether vested or unvested, based on their respective rights to receive dividends, whether or not declared.

Diluted loss per share attributable to common stockholders is based on the weighted-average number shares of common stock outstanding adjusted for the dilutive effect of share-based awards and the potential dilutive effect of warrants, convertible notes and convertible preferred stock. Diluted loss per share attributable to common stockholders is the same as basic loss per share attributable to common stockholders for all periods presented because the Company has reported net losses and the effects of including the potentially dilutive items were anti-dilutive.

Revenue Recognition

The Company derives its revenue from the following sources:

•

Subscriptions to the Company’s solutions—Clients pay subscription fees for access to the Company's solutions for a specified period of time, typically three years for the Company's core solution or monthly, annually, or three-year periods for the Company's CSB and Cornerstone for Salesforce solutions. Fees are based on a number of factors, including the number of users having access to a solution. The Company generally recognizes revenue from subscriptions ratably over the term of the agreement.

•

Consulting services—The Company offers its clients assistance in implementing its solutions and optimizing their use. Consulting services include application configuration, system integration, business process re-engineering, change management, and training services. Services are billed either on a time-and-material or a fixed-fee basis. These services are generally purchased as part of a subscription arrangement and are typically performed within the first several months of the arrangement. Clients may also purchase consulting services at any other time. Consulting services are performed by the Company directly or by third-party professional service providers the Company engages. Clients may also choose to perform these services themselves or engage their own third-party service providers. The Company generally recognizes revenue from fixed fee consulting services using the proportional performance method over the period the services are performed and as time is incurred for time-and-material arrangements.

•

E-learning content—The Company resells third-party on-line training content, referred to as e-learning content, to its clients. In addition, the Company also hosts other e-learning content provided by its clients. The Company generally recognizes revenue from the resale of e-learning content as it is delivered and recognizes revenue from hosting as the hosting services are provided.

The Company recognizes revenue when: (i) persuasive evidence of an arrangement for the sale of the Company's solutions or consulting services exists, (ii) the solutions have been made available or delivered, or services have been performed, (iii) the sales price is fixed or determinable, and (iv) collectability is reasonably assured. The timing and amount the Company recognizes as revenue is determined based on the facts and circumstances of each client arrangement. Evidence of an arrangement consists of a signed client agreement. The Company considers that delivery of a solution has commenced once it provides the client with log-in information to access and use the solution. If non-standard acceptance periods or non-standard performance criteria exist, revenue recognition commences upon the satisfaction of the non-standard acceptance or performance criteria, as applicable. Standard acceptance or performance clauses relate to the Company’s solutions meeting certain perfunctory operating thresholds. Fees are fixed based on stated rates specified in the client agreement. If collectability is not considered reasonably assured, revenue is deferred until the fees are collected. The majority of client arrangements include multiple deliverables, such as subscriptions to the Company’s software solutions and consulting services. The Company therefore recognizes revenue in accordance with the guidance for arrangements with multiple deliverables under Accounting Standards Update (“ASU”) 2009-13 “Revenue Recognition (Topic 605)—Multiple-Deliverable Revenue Arrangements—a Consensus of the Emerging Issues Task Force,” or ASU 2009-13. As clients do not have the right to the underlying software code for the solutions, the Company’s revenue arrangements are outside the scope of software revenue recognition guidance. The Company’s agreements generally do not contain any cancellation or refund provisions other than in the event of the Company’s default.

For multiple-deliverable revenue arrangements, the Company first assesses whether each deliverable has value to the client on a standalone basis. The Company has determined that the solutions have standalone value, because, once access is given to a client, the solutions are fully functional and do not require any additional development, modification or customization. Consulting services have standalone value because third-party service providers, distributors or clients themselves can perform these services without the Company’s involvement. The consulting services assist clients with the configuration and integration of the Company’s solutions. The performance of these services generally does not require highly specialized or skilled individuals and are not essential to the functionality of the solutions.

Based on the standalone value of the deliverables, and since clients do not have a general right of return relative to the included consulting services, the Company allocates revenue among the separate deliverables in an arrangement under the relative selling price method using the selling price hierarchy established in ASU 2009-13. This hierarchy requires the selling price of each deliverable in a multiple deliverable arrangement to be based on, in descending order: (i) vendor-specific objective evidence of fair value (“VSOE”), (ii) third-party evidence of fair value (“TPE”) or (iii) management’s best estimate of the selling price (“BESP”).

The Company is generally not able to determine VSOE or TPE for its deliverables, because the deliverables are sold separately and within a sufficiently narrow price range only infrequently, and because management has determined that there are no third-party offerings reasonably comparable to the Company’s solutions. Accordingly, the selling prices of subscriptions to the solutions and consulting services is based on BESP. The determination of BESP requires the Company to make significant estimates and judgments. The Company considers numerous factors, including the nature of the deliverables themselves; the geography, market conditions and competitive landscape for the sale; internal costs; and pricing and discounting practices. The determination of BESP is made through consultation with and formal approval by senior management. The Company updates its estimates of BESP on an ongoing basis as events and as circumstances may require.

After the fair value of revenue allocable to each deliverable in a multiple deliverable arrangement based on the relative selling price method is determined, revenue is recognized for each deliverable based on the type of deliverable. For subscriptions to the solutions, revenue is recognized on a straight-line basis over the subscription term, which is typically three years. For consulting services, revenue is recognized using the proportional performance method over the period the services are performed.

In a limited number of cases, multiple deliverable arrangements may include consulting services that do not have value on a standalone basis separate from a solution, such as when the client’s intended use of a solution requires enhancements to its underlying features and functionality. In these cases, revenue is recognized as one unit of accounting on a straight-line basis from the point at which the consulting services that do not have value on a standalone basis have been completed and accepted by the client, through the remaining term of the agreement.

For arrangements in which the Company resells third-party e-learning training content to clients or hosts client or third-party e-learning training content provided by the client, revenue is recognized in accordance with accounting guidance as to when to report gross revenue as a principal or report net revenue as an agent. The Company recognizes third-party content revenue at the gross amount invoiced to clients when (i) the Company is the primary obligor, (ii) the Company has latitude to establish the price charged, and (iii) the Company bears the credit risk in the transaction. For arrangements involving the sale of third-party content, clients are charged for the content based on pay-per-use or a fixed rate for a specified number of users, and revenue is recognized at the gross amount invoiced as the content is delivered. For arrangements where clients purchase third-party content directly from a third-party vendor, or provide it themselves, and the Company integrates the content into a solution, the Company charges a fee per user or fee based on estimated bandwidth. In such cases, the fees are recognized at the net amount charged by the Company for hosting services as the content is delivered.

Revenue generated from sales arrangements through distributors, including revenue generated through the Company’s five-year global distributor agreement with ADP described below, is recognized in accordance with the Company’s revenue recognition policies as described above at the amount invoiced to the distributor. In these arrangements, the Company recognizes revenue in accordance with accounting guidance as to when to report gross revenue as a principal and when to report net revenue as an agent. The Company recognizes revenue at the net amount invoiced to the distributor, as opposed to the gross amount the distributor invoices their end customer, as the Company has determined that (i) the Company in not the primary obligor in these arrangements, (ii) the Company does not have latitude to establish the price charged to the end-customer and (iii) the Company does not bear the credit risk in the transaction.

In connection with a five-year global distributor agreement entered into in May 2009 with a global distributor, ADP, the Company entered into a warrant agreement to provide additional incentives to ADP. In April 2012, the Company signed an amendment to extend the term of the distributor agreement through 2017. The warrant agreement provided that ADP was eligible to earn fully vested and immediately exercisable ten-year warrants to purchase between zero and 886,096 shares of the Company’s common stock at a price of $0.53 per share if ADP met specified sales targets for each contract year until the earlier of the completion of the five-year term of the distributor agreement or the completion of an initial public offering of the Company’s common stock. When ADP achieved the defined sales target and earned a warrant, the Company recorded the fair value of such warrant as a reduction of revenue. For the first contract year ended June 30, 2010, no reductions of revenue were recorded, based on the Company’s conclusion that the defined sales targets had not been met by ADP.

During the year ended December 31, 2011, the Company recorded a reduction of revenue of $2.5 million in connection with the issuance of warrants to ADP. The Company recorded the fair value of the warrants as reduction of revenue as the agreement provides ADP with the right to be the distributor of the Company’s services and the Company estimates that ADP will purchase additional services from the Company. See Note 11 for additional information about warrants under the ADP agreement.

The Company records amounts that have been invoiced to its clients in accounts receivable and in either deferred revenue or revenue depending on whether the revenue recognition criteria described above have been met. Deferred revenue that will be recognized during the succeeding twelve month period from the respective balance sheet date is recorded as current deferred revenue and the remaining portion is recorded as noncurrent.

Cost of Revenue

Cost of revenue consists primarily of costs related to hosting the Company’s solutions; personnel and related expenses, including stock-based compensation, and related expenses for network infrastructure, IT support, consulting services and on-going client support staff; payments to external service providers; amortization of capitalized software costs, developed technology and licensing fees; and referral fees. In addition, the Company allocates a portion of overhead, such as rent, IT costs, depreciation and amortization and employee benefits costs, to cost of revenue based on headcount. Costs associated with providing consulting services are recognized as incurred when the services are performed. Out-of-pocket travel costs related to the delivery of professional services are typically reimbursed by the client and are accounted for as both revenue and expense in the period in which the cost is incurred.

Commission Payments

The Company defers commissions paid to its sales force because these amounts are recoverable from the future revenue from the non-cancelable client agreements that gave rise to the commissions. Commissions are deferred on the balance sheet and are amortized to sales and marketing expense over the term of the client agreement in proportion to the revenue that is recognized. Commissions are considered direct and incremental costs to client agreements and were generally paid in the periods the Company received payment from the client under the associated client agreement. Commencing in the fourth quarter of 2012, the Company pays commissions between 45 and 75 days after execution of the client agreement.

During the years ended December 31, 2013, 2012, and 2011, the Company deferred $22.8 million, $16.1 million and $7.7 million, respectively, of commissions on the balance sheet. During the years ended December 31, 2013, 2012, and 2011, the Company amortized $15.5 million, $10.3 million and $6.5 million to sales and marketing expense, respectively. As of December 31, 2013 and 2012, deferred commissions on the Company’s consolidated balance sheets totaled $16.6 million and $9.4 million, respectively.

Research & Development

Research and development expenses consist primarily of personnel and related expenses for the Company’s research and development staff, including salaries, benefits, bonuses and stock-based compensation; the cost of certain third-party service providers; and allocated overhead. Research and development expenses, other than software development costs qualifying for capitalization, are expensed as incurred. The Company's research and development expenses were $21.3 million in 2013, $14.9 million in 2012, and $10.1 million in 2011.

Advertising

Advertising expenses for 2013, 2012, and 2011, were $2.0 million, $0.4 million, and $0.3 million, respectively, and are expensed as incurred.

Stock-Based Compensation

The Company accounts for stock-based compensation awards granted to employees and directors by recording compensation expense based on the awards' estimated fair value. The Company estimates the fair value of its stock-based compensation awards as of the date of grant using the Black-Scholes option-pricing model. The resulting fair value, net of estimated forfeitures, is recognized over the period during which an employee is required to provide service in exchange for the award, usually the vesting period, which is generally four years. The Company recognizes the fair value of stock-based compensation for awards which contain only service conditions on a straight-line basis over the vesting period of the awards. The Company recognizes the fair value of stock-based compensation for awards which contain performance conditions based upon the probability of that performance condition being met, net of estimated forfeitures, using the graded vesting method. Estimated forfeitures are based upon the Company's historical experience and the Company revises its estimates, if necessary, in subsequent periods if actual forfeitures differ from initial estimates.

The Black-Scholes option pricing model requires assumptions, including estimating the value per share of the Company's common stock (for periods prior to the Company's IPO), estimated volatility, risk-free rate, expected term and estimated dividend yield. The assumptions used in calculating the fair value of stock-based compensation awards represents the Company's best estimates, based on management judgment. The Company uses the average volatility of similar publicly traded companies as an estimate for estimated volatility. The Company determines the expected term of awards which contain only service conditions using the simplified approach, in which the expected term of an award is presumed to be the mid-point between the vesting date and the expiration date of the award, as the Company does not have sufficient historical data relating to stock-option exercises. For awards granted which contain performance conditions the Company estimates the expected term based on estimates of post-vesting employment termination behavior taking into account the life of the award. The risk-free interest rate for periods within the expected or contractual life of the option, as applicable, is based on the United States Treasury yield curve in effect during the period the options were granted. The estimated dividend yield is zero, as the Company has not declared, and does not currently intend to declare, dividends in the foreseeable future.

The following information represents the weighted average of the assumptions used in the Black-Scholes option-pricing model:

For the Years Ended December 31,

2013

2012

2011

Risk-free interest rate

1.5

%

1

%

1.7

%

Expected term (in years)

6

5.8

6

Estimated dividend yield

—

%

—

%

—

%

Estimated volatility

51.5

%

53.9

%

56.9

%

Due to the full valuation allowance provided on its net deferred tax assets, the Company has not recorded any tax benefit attributable to stock-based compensation expense as of December 31, 2013 and 2012.

Capitalized Software Costs

The Company capitalizes the costs associated with software developed or obtained for internal use, including costs incurred in connection with the development of the solutions, when the preliminary project stage is completed, management has decided to make the project a part of its future offering, and the software will be used to perform the function intended. These capitalized costs include external direct costs of materials and services consumed in developing or obtaining internal-use software, personnel and related expenses for employees who are directly associated with and who devote time to internal-use software projects and, when material, interest costs incurred during the development. Capitalization of these costs ceases once the project is substantially complete and the software is ready for its intended purpose. Costs incurred for upgrades and enhancements to the solutions are also capitalized. Post-configuration training and maintenance costs are expensed as incurred. Capitalized software costs are amortized to cost of revenue using the straight-line method over an estimated useful life of the software of three years, commencing when the software is ready for its intended use. The Company does not transfer ownership of, or lease its software to its clients.

During the years ended December 31, 2013, 2012 and 2011, the Company capitalized $7.9 million, $5.7 million, and $3.3 million, respectively, of software development costs to the balance sheet. During the years ended December 31, 2013, 2012 and 2011, the Company amortized $4.3 million, $2.8 million, and $1.9 million to cost of revenue, respectively. Based on the Company’s capitalized software costs at December 31, 2013, estimated amortization expense of $5.0 million, $3.7 million, $1.8 million and $0.2 million is expected to be recognized in 2014, 2015, 2016 and 2017, respectively.

Warrants to Purchase Common and Preferred Stock

Warrants to Purchase Common Stock

The Company has issued warrants to purchase common stock in connection with debt arrangements and the purchase of certain domain names and has accounted for these warrants in stockholders’ equity at fair value upon issuance, based on the specific terms of such warrant arrangements.

In addition, in connection with a five-year global distributor agreement with ADP entered into in May 2009, the Company entered into a warrant agreement to provide additional incentives to ADP. See Note 11 for additional information about warrants under the ADP agreement.

Warrants to Purchase Preferred Stock

The Company issued warrants to purchase preferred stock in connection with debt arrangements and preferred stock financings and accounted for these warrants as liabilities at fair value at the time of issuance, because the underlying shares of convertible preferred stock were redeemable or contingently redeemable, including in the case of a deemed liquidation, which may have obligated the Company to transfer assets to the warrant holders. The preferred stock warrants were recorded at fair value at the time of issuance. Changes in the fair value of the preferred stock warrants each reporting period were recorded as part of other expense in the Company’s statement of operations until the earlier of: (i) the exercise or expiration of the warrants; or (ii) the completion of an initial public offering. Upon the completion of the Company's IPO, all the warrants to purchase preferred stock expired, with the exception of warrants to purchase 140,625 shares of Series D preferred stock and warrants to purchase 380,000 shares of Series C preferred stock. These remaining warrants automatically became warrants to purchase common stock and were classified as equity. Prior to the completion of the Company’s IPO in March 2011, all warrants to purchase preferred stock were exercised. The fair value of the preferred stock warrants was estimated using the Black-Scholes option-pricing model.

Comprehensive Loss

Comprehensive loss encompasses all changes in equity other than those arising from transactions with stockholders, and consists of net loss, currency translation adjustments and unrealized gains or losses on investments. For the years ended December 31, 2013, 2012 and 2011, accumulated other comprehensive income (loss) comprised a cumulative translation adjustment. For the year ended December 31, 2013, accumulated other comprehensive income also included net unrealized gains on investments.

Income Taxes

The Company uses the liability method of accounting for income taxes. Under the liability method, deferred taxes are determined based on the temporary differences between the financial statement and tax basis of assets and liabilities, using tax rates expected to be in effect during the years in which the bases differences are expected to reverse. A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized. In determining the need for valuation allowances, the Company considers projected future taxable income and the availability of tax planning strategies. The Company has recorded a full valuation allowance to reduce its United States and United Kingdom net deferred tax assets to zero, as it has determined that it is not more likely than not that any of the Company’s deferred tax assets will be realized.

The Company has assessed its income tax positions and recorded tax benefits for all years subject to examination, based upon its evaluation of the facts, circumstances and information available at each period end. For those tax positions where the Company has determined there is a greater than 50% likelihood that a tax benefit will be sustained, the Company has recorded the largest amount of tax benefit that may potentially be realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where it is determined there is less than 50% likelihood that a tax benefit will be sustained, no tax benefit has been recognized.

Cash and Cash Equivalents

The Company considers cash and cash equivalents to include short-term, highly liquid investments that are readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in the value, including investments with original or remaining maturities from the date of purchase of three months or less. At December 31, 2013 and 2012, cash and cash equivalents consisted of cash balances of $43.9 million and $24.9 million, respectively, and money market funds backed by United States Treasury Bills of $65.7 million and $51.5 million, respectively.

Investments in Marketable Securities

The Company’s available-for-sale investments in marketable securities are recorded at fair value, with any unrealized gains and losses, net of taxes, reported as a component of stockholders’ equity until realized or until a determination is made that an other-than-temporary decline in market value has occurred. If the Company determines that an other-than-temporary decline has occurred for debt securities that the Company does not then currently intend to sell, the Company recognizes the credit loss component of an other-than-temporary impairment in other income (expense) and the remaining portion in other comprehensive income (loss). The credit loss component is identified as the amount of the present value of cash flows not expected to be received over the remaining term of the security, based on cash flow projections. In determining whether an other-than-temporary impairment exists, the Company considers: (i) the length of time and the extent to which the fair value has been less than cost; (ii) the financial condition and near-term prospects of the issuer of the securities; and (iii) the Company’s intent and ability to retain the security for a period of time sufficient to allow for any anticipated recovery in fair value. The cost of marketable securities sold is determined based on the specific identification method and any realized gains or losses on the sale of investments are reflected as a component of interest income or expense. In addition, the Company classifies marketable securities as current or non-current based upon the maturity dates of the securities. At December 31, 2013, the Company had $199.9 million of short-term investments in marketable securities. The Company had no investments in marketable securities at December 31, 2012.

Restricted Cash

Included in current and non-current other assets at December 31, 2013 and 2012 were restricted cash of $0.2 million and $0.1 million, respectively, in relation to a standby letter of credit in British Pounds for a foreign sales arrangement with a customer in the United Kingdom.

Allowance for Doubtful Accounts

The Company bases its allowance for doubtful accounts on its historical collection experience and a review in each period of the status of the then-outstanding accounts receivable.

A reconciliation of the beginning and ending amount of allowance for doubtful accounts for the years ended December 31, 2013, 2012 and 2011, is as follows (in thousands):

2013

2012

2011

Beginning balance, January 1

$

464

$

153

$

32

Additions and adjustments

968

358

203

Write-offs

(411

)

(47

)

(82

)

Ending balance, December 31

$

1,021

$

464

$

153

Property and Equipment, Net

Property and equipment are recorded at historical cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method based upon the estimated useful lives of the assets, generally two to seven years (See Note 7).

The Company leases equipment under capital lease arrangements. The assets and liabilities under capital lease are recorded at the lesser of the present value of aggregate future minimum lease payments, including estimated bargain purchase options, or the fair value of the asset under lease. Assets under capital lease are depreciated using the straight-line method over the lesser of the estimated useful life of the asset or the term of the lease.

Leasehold improvements are depreciated on a straight-line basis over the shorter of their estimated useful lives or lease terms. Repair and maintenance costs are charged to expense as incurred, while renewals and improvements are capitalized.

Impairment of Long Lived Assets

The Company evaluates the recoverability of its long-lived assets with finite useful lives, including intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. Such triggering events or changes in circumstances may include: a significant decrease in the market price of a long-lived asset, a significant adverse change in the extent or manner in which a long-lived asset is being used, a significant adverse change in legal factors or in the business climate, the impact of competition or other factors that could affect the value of a long-lived asset, a significant adverse deterioration in the amount of revenue or cash flows expected to be generated from an asset group, an accumulation of costs significantly in excess of the amount originally expected for the acquisition or development of a long-lived asset, current or future operating or cash flow losses that demonstrate continuing losses associated with the use of a long-lived asset, or a current expectation that, more likely than not, a long-lived asset will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. The Company performs impairment testing at the asset group level that represents the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. If events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable and the expected undiscounted future cash flows attributable to the asset group are less than the carrying amount of the asset group, an impairment loss equal to the excess of the asset’s carrying value over its fair value is recorded. Fair value is determined based upon estimated undiscounted future cash flows. There were no impairment charges related to identifiable long lived assets in the years ended December 31, 2013 and 2012.

Intangible Assets

Identifiable intangible assets primarily consist of trade names and intellectual property and acquisition-related intangibles, including developed technology, customer relationships, non-compete agreements, trade names and trademarks. The Company determines the appropriate useful life of its intangible assets by performing an analysis of expected cash flows of the acquired assets. Intangible assets are amortized over their estimated useful lives ranging from two to ten years, generally using the straight line method which approximates the pattern in which the economic benefits are consumed.

Goodwill

Goodwill is not amortized, but instead is required to be tested for impairment annually and under certain circumstances. The Company performs such testing of goodwill in the fourth quarter of each year, or as events occur or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. Events or changes in circumstances which could trigger an impairment review include a significant adverse change in legal factors or in the business climate, an adverse action or assessment by a regulator, unanticipated competition, a loss of key personnel, significant changes in the manner of the Company’s use of the acquired assets or the strategy for the Company’s overall business, significant negative industry or economic trends, or significant underperformance relative to expected historical or projected future results of operations.

As part of the annual impairment test, the Company may conduct an assessment of qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the Company determines that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, it then conducts the first step of a two-step impairment test. The first step of the test for goodwill impairment compares the fair value of the applicable reporting unit with its carrying value. Fair value is determined using a discounted cash flow method and/or prevailing earnings multiples for the reporting unit. The use of discounted cash flows requires the use of various economic, market and business assumptions in developing the reporting unit’s revenue, cost and cash flow forecasts, the useful life over which cash flows will occur, and determination of the reporting unit’s weighted average cost of capital that reflect the Company’s best estimates when performing the annual impairment test.

If the fair value of a reporting unit is less than the reporting unit’s carrying value, the Company performs the second step of the test for impairment of goodwill in which the Company compares the implied fair value of the reporting unit’s goodwill with the carrying value of that goodwill. The estimate of implied fair value of goodwill may require valuations of certain internally generated and unrecognized intangible assets and other assets and liabilities. If the carrying value of the goodwill exceeds the calculated implied fair value, the excess amount will be recognized as an impairment loss. Based on the results of the annual impairment test, no impairment of goodwill existed at December 31, 2013.

Senior Convertible Notes

In accounting for senior convertible notes (the “Notes”) at issuance, the Company separated the Notes into debt and equity components pursuant to the accounting standards for convertible debt instruments that may be fully or partially settled in cash upon conversion. The fair value of the debt component was estimated using an interest rate for nonconvertible debt, with terms similar to the Notes, excluding the conversion feature. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The excess of the principal amount of the Notes over the fair value of the debt component was recorded as a debt discount and a corresponding increase in additional paid-in capital. The debt discount is accreted to interest expense over the term of the Notes using the interest method. The amount recorded to additional paid-in capital is not to be remeasured as long as it continues to meet the conditions for equity classification.

Fair Value of Financial Instruments

Fair value represents the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy is based on the following three levels of inputs, of which the first two are considered observable and the last one is considered unobservable:

•

Level 1—Quoted prices (unadjusted) in active markets for identical assets or liabilities that management has the ability to access at the measurement date.

•

Level 2—Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

•

Level 3—Unobservable inputs.

Observable inputs are based on market data obtained from independent sources.

Accretion of Preferred Stock

Prior to the completion of the Company's IPO in March 2011, the Company accreted the Series D and Series E preferred stock carrying values to their estimated redemption values over the period to their earliest redemption date, May 10, 2014, using the interest rate method. Upon the completion of the Company's IPO, all of the Series D and Series E preferred stock converted to common stock and redemption rights to the preferred stockholders were removed. For the year ended December 31, 2011, the Company recorded accretion of $5.2 million.

Concentration of Risk

Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash, cash equivalents, restricted cash, and accounts receivable. The Company’s cash and cash equivalents are deposited with several financial institutions which, at times, may exceed federally insured limits, as applicable.

Accounts receivable include amounts due from clients with principal operations primarily in the United States. The Company performs ongoing credit evaluations of its clients.

For the years ended December 31, 2013, 2012 and 2011, no single client comprised more than 10% of the Company’s revenue. No single client had an accounts receivable balance greater than 10% of total accounts receivable at December 31, 2013 or 2012.

Foreign Currency Transactions and Translation

Transactions in foreign currencies are translated into U.S. Dollars at the rates of exchange in effect at the date of the transaction. Transaction gains (losses) were approximately $(0.3) million, $0.2 million and $(0.5) million for the years ended December 31, 2013, 2012 and 2011, respectively, and are included in other, net within other income (expense), net, in the accompanying consolidated statements of operations.

The Company has entities in various countries. For entities where the local currency is different than the functional currency, the local currency financial statements have been remeasured from the local currency into the functional currency using the current exchange rate for monetary accounts and historical exchange rates for nonmonetary accounts, with exchange differences on remeasurement included in other income (loss). To the extent that the functional currency is different than the U.S Dollar, the financial statements have then been translated into U.S. Dollars using period-end exchanges rates for assets and liabilities and average exchanges rates for the results of operations. Foreign currency translation gains and losses are included as a component of accumulated other comprehensive income or loss in the consolidated balance sheets.

Recent Accounting Pronouncements

In February 2013, the Financial Accounting Standards Board (“FASB”) issued a new accounting standards update amending the accounting guidance for the presentation of comprehensive income to improve the reporting of reclassifications out of accumulated other comprehensive income. The amendment requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by significant component. The new standard is effective prospectively for reporting periods beginning after December 15, 2012. The new guidance did not have a significant impact on the Company’s disclosures and does not have an impact on the Company’s results of operations or financial position.

In March 2013, the FASB issued new accounting guidance clarifying the accounting for the release of cumulative translation adjustment into net income when a company either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning on or after December 15, 2013. The Company does not anticipate that the adoption of this guidance will have a significant impact on its financial position, results of operations or cash flows.

In July 2013, the FASB issued a new accounting standards update amending the guidance related to the presentation of unrecognized tax benefits. The accounting standards update states that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The new standard is effective for annual and interim periods for fiscal years beginning after December 15, 2013, and early adoption is permitted. The new guidance is not expected to have a significant impact on the Company’s results of operations or financial position.

Business_Acquisition

Business Acquisition	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Business Acquisition	'
	BUSINESS ACQUISITION
	On April 5, 2012, the Company completed the acquisition of all of the issued and outstanding shares of Sonar, a New Zealand based SaaS talent management vendor serving small businesses worldwide. Purchase consideration for the acquisition was approximately $12.5 million in cash and 15,530 shares of the Company’s common stock, with a fair value of approximately $0.3 million, valued on the acquisition date. Approximately $1.8 million of the cash consideration and the shares issued were placed in escrow pending resolution of any post-acquisition representations and warranties. The escrow period ended in April 2013.
	The acquisition has been accounted for under the acquisition method of accounting in accordance with the FASB’s Accounting Standards Codification (“ASC”) Topic 805, Business Combinations. As such, the Sonar assets acquired and liabilities assumed are recorded at their acquisition-date fair values. Acquisition-related transaction costs are not included as a component of consideration transferred, but are accounted for as an expense in the period in which the costs are incurred. Any excess of the acquisition consideration over the fair value of assets acquired and liabilities assumed is allocated to goodwill, which is not deductible for tax purposes. Goodwill is attributable primarily to expected synergies and other benefits, including the acquired workforce, from combining Sonar with the Company. The Company acquired Sonar to strengthen its ability to serve small businesses with less than 400 employees.
	The Company’s allocation of the total purchase consideration as of April 5, 2012 is summarized below (in thousands):
	Acquired intangible assets:
	Developed technology	$	3,800
	Customer relationships	2,400
	Non-compete agreements	610
	Domains/trademark/tradenames	320
	Total acquired intangible assets	7,130
	Goodwill	8,193
	Other assets (including cash of $76)	815
	Current liabilities	(506		)
	Deferred revenue	(427		)
	Borrowings	(557		)
	Net deferred tax liabilities	(1,809		)
	Net Assets Acquired	$	12,839
	The developed technology, customer relationships intangibles, non-compete agreements and trade names/trademarks are being amortized on a straight-line basis over 4, 4, 2.5 and 2 years, respectively, with a combined weighted-average useful life of 3.8 years.
	The Company recognized approximately $0.7 million of acquisition related costs during the year ended December 31, 2012. These costs are included in the Consolidated Statements of Operations under “General and administrative”. The results of operations of Sonar have been included in the Company’s Consolidated Statements of Operations since the acquisition date of April 5, 2012.
	Concurrent with the acquisition, the Company issued 31,164 restricted shares of its common stock, valued at approximately $0.7 million, to certain Sonar shareholders who also became employees of the combined company post-acquisition. The restricted shares are subject to continued employment and the fair value of the restricted shares will be recognized as a post-acquisition compensation expense over the two-year vesting period.
	Unaudited Pro Forma Financial Information
	The following table reflects the unaudited pro forma consolidated results of operations as if the Sonar acquisition had taken place on January 1, 2011, after giving effect to certain adjustments including the amortization of acquired intangible assets and the associated tax effect and the elimination of the Company’s and Sonar’s non-recurring acquisition-related expenses (in thousands):
		For the Years Ended
		December 31,
		2013			2012			2011
		Actual			Pro Forma			Pro Forma
	Revenue	$	185,129		$	118,917		$	76,449
	Net loss	$	(40,426	)	$	(31,072	)	$	(65,342	)
	The unaudited pro forma information presented does not purport to be indicative of the results that would have been achieved had the acquisition been consummated as of January 1, 2011 nor of the results which may occur in the future. The pro forma adjustments are based upon available information and certain assumptions that the Company believes are reasonable. The unaudited pro forma information does not include any adjustments for any restructuring activities, operating efficiencies or cost savings.

Net_Loss_Per_Share_Attributabl

Net Loss Per Share Attributable to Common Stockholders	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Net Loss Per Share Attributable to Common Stockholders	'
	NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS
	The following table presents the basic and diluted loss per share attributable to common stockholders (in thousands, except per share amounts):
		For the Years Ended December 31,
		2013				2012			2011
	Net loss attributable to common stockholders	$	(40,426	)		$	(31,390	)	$	(69,108	)
	Weighted-average shares of common stock outstanding, excluding shares issued upon early exercise of unvested options and unvested restricted stock	51,427				49,929			39,824
	Net loss per share attributable to common stockholders—basic and diluted	$	(0.79	)		$	(0.63	)	$	(1.74	)
	The following table presents the number of anti-dilutive shares excluded from the calculation of diluted net loss per share attributable to common stockholders (in thousands):
		December 31,
		2013			2012			2011
	Options to purchase common stock and restricted stock units	7,730			7,331			5,845
	Convertible notes	4,682			—			—
	Common stock warrants	4,682			—			130
	Shares issued for purchase consideration held in escrow	—			16			—
	Common stock subject to repurchase right	—			10			30
	Other restricted common stock	12			31			—
	Total shares excluded from net loss per share attributable to common stockholders	17,106			7,388			6,005
	Under the treasury stock method, the convertible notes and common stock warrants will have a dilutive impact on net earnings per share when the average stock price for the period exceeds the respective conversion prices and the Company has net income attributable to common stockholders. The Company also entered into note hedge transactions (“Note Hedges”) in connection with the convertible notes with respect to its common stock to minimize the impact of potential economic dilution upon conversion of the convertible notes. The Note Hedges were outstanding as of December 31, 2013. Since the beneficial impact of the Note Hedges were anti-dilutive, they were excluded from the calculation of diluted net income (loss) per share. See Note 9 of the Notes to Consolidated Financial Statements.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets	'
	GOODWILL AND INTANGIBLE ASSETS
	Finite-lived Intangibles
	The Company has finite-lived intangible assets which are amortized over their estimated useful lives on a straight line basis. The following table presents the gross carrying amount and accumulated amortization of finite-lived intangible assets as of December 31, 2013 and 2012 (in thousands):
		December 31, 2013							31-Dec-12
		Gross		Accumulated			Net		Gross		Accumulated			Net
		Carrying		Amortization			Carrying		Carrying		Amortization			Carrying
		Amount					Amount		Amount					Amount
	Developed technology	$	3,800	$	(1,649	)	$	2,151	$	3,800	$	(700	)	$	3,100
	Customer relationships	2,400		(1,042		)	1,358		2,400		(441		)	1,959
	Domains/trademarks/tradenames	320		(278		)	42		320		(118		)	202
	Software license rights	1,654		(759		)	895		1,654		(459		)	1,195
	Non-compete agreements	610		(424		)	186		610		(179		)	431
	Total	$	8,784	$	(4,152	)	$	4,632	$	8,784	$	(1,897	)	$	6,887
	In January 2012, the Company acquired intellectual property rights associated with a software application for $0.8 million, financed through a third-party debt arrangement.
	In April 2012, the Company recorded additional finite-lived intangible assets totaling $7.1 million, primarily related to developed technology, customer relationships, trademarks and trade names, and non-compete agreements from the acquisition of Sonar (see Note 3).
	Total amortization expense from finite-lived intangible assets were $2.3 million, $1.7 million and $0.1 million for the years ended December 31, 2013, 2012 and 2011, respectively. Amortization expense of $1.3 million, $1.0 million and $0.1 million for the years ended December 31, 2013, 2012 and 2011, respectively, related to developed technology and software license rights was recorded in cost of revenue and the remainder in “Amortization of certain acquired intangible assets” in the accompanying Consolidated Statements of Operations.
	The following table presents the Company’s estimate of remaining amortization expense for each of the five succeeding fiscal years for finite-lived intangible assets that existed at December 31, 2013 (in thousands):
	2014	$	2,078
	2015	1,840
	2016	555
	2017	146
	2018	13
	Total	$	4,632
	Estimated remaining amortization expense of $1.2 million, $1.2 million, $0.4 million, $0.1 million, and $13,000 will be recorded in cost of revenue for 2014, 2015, 2016, 2017, and 2018, respectively. The remaining estimated amortization expense will be recorded in amortization of acquired intangible assets within operating expenses.
	Goodwill
	The following table presents the changes in the carrying amount of goodwill for the years ended December 31, 2013 and 2012 (in thousands):
	Goodwill as of December 31, 2011	$	—
	Goodwill from Sonar acquisition, April 5, 2012	8,193
	Goodwill as of December 31, 2012	$	8,193
	Adjustments	—
	Goodwill as of December 31, 2013	$	8,193
	The goodwill recorded in connection with the Sonar acquisition is primarily related to the expected long-term synergies and other benefits, including the acquired workforce, from the acquisition.

Other_Balance_Sheet_Amounts

Other Balance Sheet Amounts	12 Months Ended
	Dec. 31, 2013
Balance Sheet Related Disclosures [Abstract]	'
Other Balance Sheet Amounts	'
	OTHER BALANCE SHEET AMOUNTS
	The balance of property and equipment, net is as follows (in thousands):
		Useful Life		December 31,
				2013				2012
	Computer equipment and software	2 – 5 years		$	15,768			$	9,976
	Furniture and fixtures	7 years		2,265				869
	Leasehold improvements	2 – 6 years		4,190				1,520
	Renovation in progress	n/a		954				1,148
				23,177				13,513
	Less: accumulated depreciation and amortization			(8,741		)		(5,566		)
	Total property and equipment, net			$	14,436			$	7,947
	Depreciation expense for the years ended December 31, 2013, 2012 and 2011 was $3.2 million, $2.5 million, $1.8 million, respectively. At December 31, 2013 and 2012, property and equipment includes computer equipment and software under capital leases with a cost basis of $2.8 million and $4.6 million, respectively, and accumulated depreciation of $2.0 million and $2.8 million, respectively. Depreciation of computer equipment and software under capital leases was $0.9 million, $1.1 million, and $0.9 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	The balance of accrued expenses is as follows (in thousands):
		December 31,
		2013				2012
	Accrued bonuses	$	6,860			$	5,229
	Accrued commissions	7,246				3,826
	Other accrued expenses	8,182				5,931
	Total accrued expenses	$	22,288			$	14,986

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	FAIR VALUE OF FINANCIAL INSTRUMENTS
	Assets and liabilities measured at fair value on a recurring basis include the following as of December 31, 2013 and 2012 (in thousands):
		December 31, 2013											31-Dec-12
		Fair Value			Level 1			Level 2			Level 3		Fair Value		Level 1		Level 2		Level 3
	Cash equivalents	$	65,700		$	65,700		$	—		$	—	$	51,521	$	51,521	$	—	$	—
	Corporate bonds	78,609			—			78,609			—		—		—		—		—
	Agency bonds	121,316			—			121,316			—		—		—		—		—
		$	265,625		$	65,700		$	199,925		$	—	$	51,521	$	51,521	$	—	$	—
	The Company’s cash equivalents at December 31, 2013 and 2012 consisted of money market funds with original maturity dates of three months or less backed by U.S. Treasury Bills. Cash equivalents are classified as Level 1.
	As of December 31, 2013, corporate and agency bonds were classified within Level 2 of the fair value hierarchy. The bonds were valued using information obtained from pricing services, which obtained quoted market prices from a variety of industry data providers, security master files from large financial institutions, and other third-party sources. The Company performed supplemental analysis to validate information obtained from its pricing services. As of December 31, 2013, no adjustments were made to such pricing information.
	Warrants
	The Company’s preferred stock warrants were recorded at fair value and were determined to be Level 3 fair value items. The changes in the fair value of preferred stock warrants are summarized below (in thousands):
		December 31,
		2011
	Fair value at beginning of period	$	39,756
	Changes in fair value of preferred stock warrant liabilities recorded in the statement of operations	42,559
	Exercise of preferred stock warrants	(82,315		)
	Fair value at end of period	$	—
	The fair value of the warrants to purchase the Company’s preferred stock was determined using a Black-Scholes option-pricing model.
	The following weighted-average assumptions were used to determine the fair value of the Series C, Series D, and Series E Preferred Stock warrants at the exercise date during March 2011:
		Series C			Series D			Series E
	Risk-free interest rate	0.1		%	0.1		%	0.1		%
	Expected term (in years)	0			0			0
	Estimated dividend yield	—			—			—
	Weighted-average estimated volatility	43.1		%	43.1		%	43.1		%
	Fair value (in thousands)	$	3,905		$	56,445		$	21,965
	Senior Convertible Notes
	The convertible notes are shown in the accompanying consolidated balance sheets at their original issuance value, net of unamortized discount, and are not remeasured to fair value each period. The approximate fair value of our convertible notes as of December 31, 2013 was $305.4 million. The fair value of the convertible notes were estimated on the basis of quoted market prices, which, due to limited trading activity, are considered Level 2 in the fair value hierarchy.

Debt_and_Other_Financing_Arran

Debt and Other Financing Arrangements	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Debt and Other Financing Arrangements	'
	DEBT AND OTHER FINANCING ARRANGEMENTS
	Senior Convertible Notes
	In 2013, the Company issued senior convertible notes (the “Notes”) raising gross proceeds of $253.0 million.
	The Notes are governed by an Indenture, dated June 17, 2013 (“Indenture”), between the Company and U.S. Bank National Association, as trustee. The Notes mature on July 1, 2018, unless earlier repurchased or converted, and bear interest at a rate of 1.50% per year payable semi-annually in arrears on January 1 and July 1 of each year, commencing January 1, 2014.
	The Notes are convertible at an initial conversion rate of 18.5046 shares of common stock per $1,000 principal amount of Notes, which represents an initial conversion price of approximately $54.04 per share, subject to adjustment for anti-dilutive issuances, voluntary increases in the conversion rate and make-whole adjustments upon a fundamental change. A fundamental change includes a change in control, delisting of the Company's stock and a liquidation of the Company. Upon conversion, the Company will deliver cash for the principal amount, and the Company has the right to settle any amounts in excess of the principal in cash or shares.
	Prior to April 1, 2018, the Notes are only convertible upon satisfaction of certain conditions as follows:
	•	during any calendar quarter after September 30, 2013, if the last reported sale price of common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day;
	•	during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of the Notes for each trading day of that five consecutive trading day period was less than 98% of the product of the last reported sale price of common stock and the conversion rate on each such trading day; or
	•	upon the occurrence of specified corporate events as defined in the Indenture.
	Holders of the Notes may convert their Notes at anytime on or after April 1, 2018, until the close of business on the second scheduled trading day immediately preceding the maturity date.
	The holders of the Notes may require the Company to repurchase all or a portion of their Notes at a cash repurchase price equal to 100% of the principal amount of the Notes being repurchased, plus accrued and unpaid interest, upon a fundamental change and events of default, including non-payment of interest or principal and other obligations under the Indenture.
	In accounting for the Notes at issuance, the Company separated the Notes into debt and equity components pursuant to the accounting standards for convertible debt instruments that may be fully or partially settled in cash upon conversion. The fair value of the debt component was estimated using an interest rate for nonconvertible debt, with terms similar to the Notes, excluding the conversion feature. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The excess of the principal amount of the Notes over the fair value of the debt component was recorded as a debt discount and a corresponding increase in additional paid-in capital. The debt discount is accreted to interest expense over the term of the Notes using the interest method. The amount recorded to additional paid-in capital is not to be remeasured as long as it continues to meet the conditions for equity classification. Upon issuance of the $253.0 million of Notes, the Company recorded $214.3 million to debt, and $38.7 million to additional paid-in capital for the debt discount.
	The Company incurred transaction costs of approximately $7.3 million related to the issuance of the Notes. In accounting for these costs, the Company allocated the costs to the debt and equity components in proportion to the allocation of proceeds from the issuance of the Notes to such components. Transaction costs allocated to the debt component of $6.2 million are deferred as an asset and amortized to interest expense over the term of the Notes. The transaction costs allocated to the equity component of $1.1 million were recorded to additional paid-in capital. The transaction costs allocated to the debt component were recorded as deferred offering costs in other noncurrent assets.
	The net carrying amount of the liability component of the Notes as of December 31, 2013 consists of the following (in thousands):
	Principal amount	$	253,000
	Unamortized debt discount	(35,035		)
	Net carrying value	$	217,965
	The following table presents the interest expense recognized related to the Notes for year ended December 31, 2013 (in thousands):
		Year Ended  December 31,
		2013
	Contractual interest expense at 1.5% per annum	$	2,045
	Amortization of debt issuance costs	591
	Accretion of debt discount	3,681
	Total	$	6,317
	The net proceeds from the Notes were approximately $246.0 million after payment of the initial purchasers' offering expenses. The Company used approximately $49.5 million of the net proceeds of the Notes offering to pay the cost of the Note Hedges described below, which was partially offset by $23.2 million of the proceeds from the Company's sale of the Warrants also described below.
	Note Hedges
	Concurrent with the issuance of the Notes, the Company entered into note hedges (“Note Hedges”) with certain bank counterparties, with respect to its common stock. The Company paid $49.5 million for the Note Hedges. The Note Hedges cover approximately 4.7 million shares of the Company's common stock at a strike price of $54.04 per share, and are exercisable by the Company upon conversion of the Notes. The Note Hedges will expire upon the maturity of the Notes. The Note Hedges are intended to reduce the potential economic dilution upon conversion of the Notes in the event that the fair value per share of the Company's common stock at the time of exercise is greater than the conversion price of the Notes.
	Warrants
	Separately and concurrently, the Company entered into warrant transactions, whereby it sold warrants to the same bank counterparties as the Note Hedges to acquire up to 4.7 million shares of the Company's common stock at a strike price of $80.06 per share (“Warrants”), subject to anti-dilution adjustments. The Company received proceeds of $23.2 million from the sale of the Warrants. The Warrants expire at various dates during 2018 and 2019. If the fair value per share of the Company's common stock exceeds the strike price of the Warrants, the Warrants will reduce diluted earnings per share to the extent that the calculation does not have an anti-dilutive effect.
	The amounts paid and received for the Note Hedges and the Warrants have been recorded in additional paid-in capital. The fair value of the Note Hedges and the Warrants are not remeasured through earnings each reporting period.
	Silicon Valley Bank
	In November 2012, the Company amended its SVB Credit Facility to allow for additional loan advances up to an aggregate of $5.0 million for the purchase of equipment. In June 2013, concurrent with the issuance of the Notes, the Company repaid its total outstanding borrowings under the SVB Credit Facility in the amount of $3.0 million. The SVB Credit Facility was extinguished upon the June 2013 repayment.
	Other Debt Arrangements
	The Company enters into other debt arrangements with finance companies to finance the purchase of property and equipment and software. As of December 31, 2013 and 2012, total amounts outstanding under these arrangements were $0.9 million and $1.4 million, respectively. Principal and interest is generally due monthly, through January 2016.
	Maturities of outstanding borrowings under the other debt arrangements as of December 31, 2013 were as follows for each year ending December (in thousands):
	2014	$	519
	2015	382
	2016	10
	Total long-term debt	$	911
	The weighted-average interest rate on borrowings for the years ended December 31, 2013 and 2012 was 7.0% and 5.2%, respectively.
	The estimated fair value of the Company’s debt was $0.9 million and $1.4 million at December 31, 2013 and 2012, respectively. The fair value was estimated based on discounted cash flow analyses using appropriate current discount rates, taking into consideration the particular terms of the borrowing agreements, at the end of the respective periods. The carrying value of the Company’s line of credit was considered to approximate fair market value, as the interest rates of these instruments were based predominantly on variable reference rates. These estimates involve considerable judgment and changes in those assumptions could significantly affect the estimates.
	Although the Company has determined the estimated fair value amounts using commonly accepted valuation methodologies, judgment is required in interpreting market data to develop the estimates of fair value. Accordingly, the estimates are not necessarily indicative of the amounts the Company, or holders of the instruments, could realize in a current market exchange. The use of different assumptions and/or estimation methodologies could have a material effect on the estimated fair values. The fair value estimates are based on information available as of December 31, 2013 and 2012. These amounts have not been revalued since those dates, and current estimates of fair value could differ significantly from the amounts presented.

Capitalization

Capitalization	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
Capitalization	'
	CAPITALIZATION
	As of December 31, 2013, the Company’s authorized stock consists of 1,000,000,000 shares of common stock, par value of $0.0001 per share, and 50,000,000 shares of preferred stock, par value of $0.0001 per share. No shares of preferred stock were issued or outstanding at December 31, 2013 and 2012.
	Upon the completion of the Company’s IPO in March 2011, all of the then-outstanding shares of preferred stock were automatically converted into 28,809,031 shares of common stock on a one-for-one basis.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2013
Warrants [Abstract]	'
Warrants	'
	WARRANTS
	Warrants to Purchase Common Stock
	In addition to the warrants issued during 2013 as discussed in Note 9, the Company has issued warrants to purchase the Company’s common stock in connection with debt arrangements, a distributor agreement and the purchase of certain domain names. All warrants were fully vested, non-forfeitable and immediately exercisable upon issuance and are equity classified. At December 31, 2013, no additional warrants to purchase common stock, other than as discussed in Note 9, were outstanding. During 2012, warrants to purchase 130,000 shares of common stock were exercised at an exercise price of $1.60 per share.
	During 2011, 898,447 shares of common stock, including 133,000 shares issued upon exercise of warrants that were granted to ADP in 2011 as discussed below, were issued upon the exercise of common stock warrants at a weighted-average exercise price of $0.95 per share.
	On May 6, 2009, the Company entered into a five-year global distributor agreement with ADP that provides ADP the right to distribute the Company’s core solution to its customers under ADP’s name. In connection with the distributor agreement, the Company also entered into a warrant agreement to provide additional incentives to ADP. The warrant agreement provided that ADP was eligible to earn fully vested and immediately exercisable ten-year warrants to purchase between zero and 886,096 shares of the Company’s common stock at an exercise price of $0.53 per share if ADP met specified sales targets for each contract year until the earlier of the completion of the five-year term of the distributor agreement or the completion of an initial public offering of the Company’s common stock. When ADP achieved the defined sales targets and earned a warrant for a contract year, the Company recorded the fair value of such warrant as a reduction of revenue. The Company determined the fair value of these warrants using a Black-Scholes option-pricing model, which incorporated several estimates and assumptions that were subject to significant judgment.
	On November 24, 2010, the Company amended its warrant agreement with ADP to modify certain definitions related to future sales targets, to acknowledge that no warrants would be issued for the contract year ended June 30, 2010 and to remove the anti-dilution provisions in the warrant agreement. In connection with the amendment, the Company issued ADP a fully vested and non-forfeitable warrant to purchase 360,000 shares of its common stock at an exercise price of $0.01 per share, which was valued at approximately $2.9 million as of the amendment date using the Black-Scholes option pricing model. This amount was recorded as a reduction of revenue in the fourth quarter of 2010 as the agreement provides ADP with the right to be distributor of the Company’s services and the Company estimates that ADP will purchase additional services from the Company. In issuing this warrant, the Company considered the strategic importance of its ongoing relationship with ADP and the expected timing of the completion of its IPO, after which ADP would no longer be eligible to earn any warrants.
	At December 31, 2010, the Company did not record any reduction in revenue for the contract year ended June 30, 2011, as the minimum specified sales target had not been achieved to earn the applicable warrant as of December 31, 2010.
	Upon the completion of the Company’s IPO, ADP was no longer eligible to earn warrants under the warrant agreement. However, ADP remained eligible to earn a warrant for the partial contract year that began on July 1, 2010 and ended on March 22, 2011, the closing date of the Company’s IPO, if it met pro-rated specified sales targets for that period. For the three months ended March 31, 2011, no reductions of revenue were recorded because the Company concluded that ADP had not met the pro-rated specified sales targets for such partial contract year based on the Company’s assessment of the contractual terms of the arrangement, and as of March 31, 2011, it was not considered probable that the Company would be required to issue a warrant for such partial contract year. Pursuant to the terms of the arrangement, the Company notified ADP that it had not earned the warrant for such partial year. ADP contended that it had met the pro-rated specified sales target for the partial contract year that would entitle ADP to a warrant to purchase 443,048 shares of the Company’s common stock at an exercise price of $0.53 per share.
	During June 2011, in order to resolve a dispute with respect to this matter, the Company issued ADP a fully vested and non-forfeitable warrant to purchase 133,000 shares of the Company’s common stock at an exercise price of $0.53 per share. The warrant was valued at approximately $2.5 million using a Black-Scholes option-pricing model as of the issuance date and was recorded as a non-cash reduction of revenue in the second quarter of 2011. In connection with the Company’s issuance of the warrant described above, ADP agreed and acknowledged that it is no longer eligible to earn or receive any additional warrants exercisable for shares of the Company’s common stock pursuant to the distributor agreement.

Stock_Option_Plans

Stock Option Plans	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock Option Plans	'
	STOCK OPTION PLANS
	1999 and 2009 Plans
	In November 1999, the Company adopted the 1999 Stock Plan (“1999 Plan”) as amended. In January 2009, the Company adopted the 2009 Plan (“2009 Plan”) as amended. Stock options granted under the 1999 and 2009 Plans may be incentive stock options or non-statutory stock options. Incentive stock options may only be granted to employees. Stock purchase rights may also be granted under the 1999 and 2009 Plans. The Board of Directors determines the period over which stock options become exercisable. However, except in specific cases of stock options granted to officers, directors and consultants, stock options become exercisable at a rate of not less than 20% per year over five years from the date the stock options are granted. Options granted under the 1999 and 2009 Plans expire ten years after the grant date and generally vest one-fourth on the first anniversary of the grant and ratably thereafter for the following thirty-six months. The exercise price of incentive stock options and non-statutory stock options cannot be less than 100% and 85%, respectively, of the fair market value per share of the Company’s common stock on the grant date as determined by the Company’s Board of Directors. If an individual owns stock representing more than 10% of the outstanding shares, the price of each incentive stock option or non-statutory stock option share must be at least 110% of fair market value, as determined by the Board of Directors. The term of the stock options is ten years except for incentive stock options granted to an individual who owns stock representing more than 10% of the outstanding shares, in which case the term of the stock options is 5 years. The Company may also grant options that are immediately exercisable upon the Board of Directors’ approval.
	At December 31, 2013, no shares are issuable under the 1999 and 2009 Plans.
	2010 Plan
	In March 2011, upon the completion of the Company’s IPO, the Company adopted the 2010 Plan and determined that it will no longer grant any additional awards under the 1999 Plan and the 2009 Plan. However, the 1999 Plan and the 2009 Plan continue to govern the terms and conditions of the outstanding awards previously granted under each respective plan. Upon the adoption of the 2010 Plan, the maximum aggregate number of shares issuable thereunder was 3,680,480 shares, plus (i) any shares subject to stock options or similar awards granted under the 1999 Plan or 2009 Plan prior to March 16, 2011 that expire or otherwise terminate without having been exercised in full and (ii) shares issued pursuant to awards granted under the 1999 Plan and 2009 Plan that are forfeited to or repurchased by the Company after March 16, 2011, with the maximum number of shares to be added to the 2010 Plan from the 1999 Plan and 2009 Plan equal to 5,614,369 shares of common stock. In addition, the number of shares available for issuance under the 2010 Plan will be annually increased on the first day of each fiscal year beginning with 2012, by an amount equal to the lesser of 5,500,000 shares, 4.5% of the outstanding shares of the Company’s common stock as of the last day of the immediately preceding fiscal year, or such other amount as the Company’s Board of Directors determines.
	Shares issued pursuant to awards under the 2010 Plan that are repurchased by the Company or that expire or are forfeited, as well as shares used to pay the exercise price of an award or to satisfy the minimum tax withholding obligations related to an award, will become available for future grant or sale under the 2010 Plan. In addition, to the extent that an award is paid out in cash rather than shares, such cash payment will not reduce the number of shares available for issuance under the 2010 Plan.
	The 2010 Plan permits the grant of incentive stock options to employees and the grant of non-statutory stock options, restricted stock, restricted stock units, stock appreciation rights, performance units and performance shares to the Company’s employees, directors and consultants.
	Stock Options
	The exercise price of stock options granted under the 2010 Plan must equal at least the fair market value of the Company’s common stock on the date of grant. The term of an incentive stock option may not exceed ten years; provided, however, that an incentive stock option held by a participant who owns more than 10% of the total combined voting power of all classes of the Company’s stock, may not have a term in excess of five years and must have an exercise price of at least 110% of the fair market value of the Company’s common stock on the grant date.
	Restricted Stock Awards
	The Company may grant restricted stock under the 2010 Plan. Restricted stock awards are grants of shares of the Company’s common stock that are subject to various restrictions, including restrictions on transferability and forfeiture provisions. Recipients of restricted stock awards generally will have voting and dividend rights with respect to such shares upon grant without regard to vesting, unless the Board of Directors provides otherwise. Shares of restricted stock that do not vest for any reason will be forfeited by the recipient and will revert to the Company. The fair value of each share of restricted stock granted is equal to the grant date fair market value of the Company’s common stock.
	Restricted Stock Units
	The Company may also grant restricted stock units under the 2010 Plan. The fair value of each restricted stock unit granted is equal to the grant date fair market value of the Company’s common stock. The payment of restricted stock units may be in the form of cash, shares, or in a combination thereof, as determined by the Board of Directors. During 2013, the Company granted 172,465 time based restricted stock units under the 2010 Plan.
	Stock Appreciation Rights
	The Company may also grant stock appreciation rights under the 2010 Plan. Stock appreciation rights allow the recipient to receive the appreciation in the price of the Company’s common stock between the date of grant and the exercise date. The payment of stock appreciation rights may be in the form of cash, shares, or in a combination thereof, as determined by the Board of Directors. As of December 31, 2013, no stock appreciation rights had been granted under the 2010 Plan.
	Performance Units/Performance Shares
	The Company may also grant performance units and performance shares under the 2010 Plan. Performance units and performance shares are awards that will result in a payment to a participant only if performance goals for a predetermined period, established by the Board of Directors, are achieved or the awards otherwise vest. The fair value of each performance unit and performance share awarded is equal to the fair market value of the Company’s common stock at the close of the applicable performance period. The payment of performance units and performance shares may be in the form of cash, shares, or a combination thereof, as determined by the Board of Directors.
	Under the 2010 Plan, 2,015,533 shares remained available for issuance, at December 31, 2013.
	Stock Options
	The Company has granted stock options which vest upon meeting service conditions and or performance conditions. Information with respect to stock options which contain performance conditions is discussed separately below. The following table summarizes the stock option activity which contain only service conditions, under the Company’s 1999, 2009 and 2010 Plans (in thousands, except per share and term information):
		Shares		Weighted			Weighted		Aggregate
				Average			Average		Intrinsic
				Exercise			Remaining		Value
				Price			Contractual
							Term
	Outstanding, December 31, 2012	6,610		$	12.49		8.2		$	112,899
	Granted	2,394		43.32
	Exercised	(1,566	)	8.58
	Forfeited	(311	)	27
	Outstanding, December 31, 2013	7,127		23.07			8.1		215,549
	Exercisable at December 31, 2013	2,890		10.46			7		123,833
	Vested and expected to vest at December 31, 2013	7,022		$	22.91		8.1		$	213,492
	The following table summarizes information about stock options, which contain only service conditions, under the Company’s equity incentive plans at December 31, 2013 (in thousands except term information):
		Options Outstanding				Options Exercisable
		at  December 31, 2013				at December 31, 2013
		Number of Options		Weighted		Number of Options		Weighted
				Average				Average
				Remaining				Remaining
				Contractual				Contractual
				Term (in				Term (in
				years)				years)
	Range of Exercise Prices
	$0.34 to $1.65	841		5.6		800		5.5
	$5.93 to $8.88	1,219		6.9		866		6.9
	$12.54 to $15.41	596		7.7		289		7.7
	$16.24 to $18.82	732		8		458		8
	$20.85 to $23.94	1,095		8.4		366		8.4
	$27.75 to $31.44	394		8.9		104		8.8
	$33.34 to $36.15	609		9.2		4		9.2
	$40.03 to $45.76	895		9.5		2		9.8
	$50.42 to $52.72	746		9.7		1		9.9
		7,127		8.1		2,890		7
	The total intrinsic value of options exercised during the years ended December 31, 2013, 2012 and 2011 was $57.7 million, $23.9 million, and $19.5 million, respectively. The Company recognized compensation expense related to stock options which contain only service conditions of $17.2 million, $10.3 million, and $3.8 million for the years ended December 31, 2013, 2012, and 2011, respectively.
	Unrecognized compensation expense relating to stock options which contain only service conditions was $59.6 million at December 31, 2013 which is expected to be recognized over a weighted-average period of 2.7 years.
	The aggregate grant date fair value of stock options which contain only service conditions granted for the years ended December 31, 2013, 2012 and 2011 was $51.5 million, $28.4 million, and $11.9 million, respectively.
	Restricted Stock Awards
	On December 1, 2011, the Company granted fully vested restricted stock awards for an aggregate of 7,500 shares of common stock with an aggregate grant date fair value of $0.1 million, which was recognized as compensation expense in 2011.
	In connection with the acquisition of Sonar, the Company issued 31,164 restricted shares of its common stock, valued at approximately $0.7 million, to certain Sonar shareholders who also became employees of the company post-acquisition. The vesting of the restricted shares is subject to continued employment, and the fair value of the restricted shares is recognized as a post-acquisition compensation expense over the 2 year vesting period (see Note 3). As of December 31, 2013, 18,698 shares were vested.
	Restricted Stock Units
	Restricted stock unit activity for the year ended December 31, 2013 under the Company’s equity incentive plans is summarized as follows (shares in thousands):
		Number of Shares		Weighted
				Average Grant  Date
Fair Value
Nonvested shares subject to restricted stock units outstanding at December 31, 2012	425		$	14.37
Granted	173		42.9
Forfeited	(2	)	40.03
Vested	(214	)	13.15
Nonvested shares subject to restricted stock units outstanding at December 31, 2013	382		$	27.81
The Company recognized compensation expense related to restricted stock units of $3.4 million, $1.7 million and $0.6 million for the years ended December 31, 2013, 2012 and 2011, respectively. Unrecognized compensation expense related to nonvested restricted stock units was $8.7 million at December 31, 2013, which is expected to be recognized as expense over the weighted-average period of 2.3 years.
Performance Based Options and Units
During 2012, the Company granted performance-based stock options and restricted stock units to certain employees. The number of awards that the employees may earn is based upon (a) a subsidiary of the Company meeting certain predetermined contracted monthly recurring revenue targets by December 31, 2015, and (b) whether the employee continues to provide service through each measurement date, as defined in the agreement applicable to the award. The awards vest generally over a four year period and have a term of 10 years. The stock options have an exercise price of $27.75 per share. The Company estimated the grant date fair value for each target level at the grant date and is recognizing stock-based compensation over the vesting period using a graded vesting model based upon the target that is probable of being achieved. Achievement of the probable target would result in stock options to purchase 53,714 shares of common stock and 12,892 restricted units vesting. The maximum number of stock options and restricted stock units that may vest should the maximum target level become probable would be 179,047 and 43,066, respectively. The Company may be required to adjust compensation cost in the future to the extent that another target level becomes probable.
The Company recognized compensation expense related to performance based awards of $0.3 million and $0.4 million for the years ended December 31, 2013 and 2012. Unrecognized compensation expense related to nonvested performance based options and restricted stock units was $0.4 million at December 31, 2013, based on the probable performance target at that date, which is expected to be recognized as expense over the weighted-average period of 2.0 years.
Stock-Based Compensation
Stock-based compensation expense related to stock options, restricted stock units and restricted stock awards is included in the following line items in the accompanying Consolidated Statement of Operations for the years ended December 31, 2013, 2012, and 2011 (in thousands):
	Years Ended December 31,
	2013			2012			2011
Cost of revenue	$	2,207		$	1,660		$	581
Sales and marketing	9,866			3,982			1,121
Research and development	2,052			949			755
General and administrative	6,715			5,616			2,045
Total	$	20,840		$	12,207		$	4,502
In certain instances the Company is responsible for payroll taxes related to stock options exercised or the underlying shares sold by its employees. The Company accrues its obligations at the time of the exercise of the stock options or the sale of the underlying shares.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	INCOME TAXES
	The components of the Company’s loss before provision (benefit) for income taxes are as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	United States	$	(36,821	)	$	(20,173	)	$	(60,300	)
	Foreign	(3,733		)	(12,006		)	(3,419		)
	Loss before provision for income taxes	$	(40,554	)	$	(32,179	)	$	(63,719	)
	The components of the provision (benefit) for income taxes attributable to continuing operations are as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	Current income tax provision:
	Federal	$	—		$	—		$	—
	State	117			—			—
	Foreign	620			176			181
	Total current income tax provision	737			176			181
	Deferred income tax benefit:
	Federal	—			—			—
	State	—			—			—
	Foreign	(865		)	(965		)	—
	Total deferred income tax benefit	(865		)	(965		)	—
	Total income tax (benefit) provision	$	(128	)	$	(789	)	$	181
	On a consolidated basis, the Company has incurred operating losses and has recorded a full valuation allowance against its United States and United Kingdom deferred tax assets for all periods to date and, accordingly, has not recorded a provision (benefit) for income taxes for any of the periods presented other than a provision (benefit) for certain foreign income taxes. Certain foreign subsidiaries and branches of the Company provide intercompany services and are compensated on a cost-plus basis, and therefore, have incurred liabilities for foreign income taxes in their respective jurisdictions. The foreign deferred tax benefit for the years ended December 31, 2013 and 2012 is primarily the result of the amortization of net deferred tax liabilities and changes in other deferred taxes recorded in connection with the 2012 acquisition of Sonar (See Note 3).
	The differences in the total provision for income taxes that would result from applying the 34% federal statutory rate to loss before provision for income taxes and the reported provision for income taxes are as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	U.S. Federal tax benefit at statutory rates	$	(13,784	)	$	(10,941	)	$	(21,688	)
	State income taxes, net of federal tax benefit	(415		)	(60		)	(916		)
	Foreign rate differential	1,354			1,008			219
	Preferred stock warrant charges	—			—			14,470
	Stock based compensation	2,039			1,360			474
	Other permanent differences	410			654			188
	Other	76			(194		)	206
	Valuation allowance	10,192			7,384			7,228
	Total income tax (benefit) provision	$	(128	)	$	(789	)	$	181
	Major components of the Company’s deferred tax assets (liabilities) at December 31, 2013 and 2012 are as follows (in thousands):
		December 31,
		2013			2012
	Deferred tax assets:
	Accrued expenses	$	2,029		$	1,306
	Long-lived intangible assets — basis difference	7,846			5,155
	Net operating loss carryforwards	33,823			24,392
	Stock-based compensation	4,818			2,671
	Deferred revenue	1,905			2,375
	Convertible note hedge	16,705			—
	Other	452			274
	Total deferred tax assets	67,578			36,173
	Valuation allowance	(48,558		)	(34,081		)
	Deferred tax assets, net of valuation allowance	19,020			2,092
	Deferred tax liabilities:
	Prepaid expenses and deferred commissions	(3,613		)	(2,029		)
	Long-lived fixed assets — basis difference	(2,136		)	(805		)
	Convertible note discount	(13,028		)	—
	Other	(120		)	—
	Total deferred tax liabilities	(18,897		)	(2,834		)
	Net deferred tax assets (liabilities)	$	123		$	(742	)
	At December 31, 2013, the Company had federal, state and foreign net operating losses of approximately $145.8 million, $152.8 million and $18.0 million, respectively. The federal net operating loss carryforward will begin expiring in 2019, the state net operating loss carryforward began expiring in 2013, and the foreign net operating loss has an unlimited carryforward period. The Internal Revenue Code of 1986, as amended, imposes substantial restrictions on the utilization of net operating losses in the event of an “ownership change” of a corporation. Accordingly, a company’s ability to use net operating losses may be limited as prescribed under Internal Revenue Code Section 382 (“IRC Section 382”). Events which may cause limitations in the amount of the net operating losses that the Company may use in any one year include, but are not limited to, a cumulative ownership change of more than 50% over a three-year period. Due to the effects of historical equity issuances, the Company has determined that the future utilization of a portion of its net operating losses is limited annually pursuant to IRC Section 382. The Company has determined that none of its net operating losses will expire because of the annual limitation.
	The Company has recorded a full valuation allowance against its otherwise recognizable United States and United Kingdom deferred income tax assets as of December 31, 2013. Management has determined, after evaluating all positive and negative historical and prospective evidence, that it is more likely than not that these assets will not be realized. The net increase to the valuation allowance of $14.5 million, $7.4 million and $7.2 million for the years ended December 31, 2013, 2012 and 2011, respectively, was primarily due to additional net operating losses generated by the Company and basis differences in long-lived assets.
	The Company has excluded excess windfall tax benefits resulting from stock option exercises as components of the Company’s gross deferred tax assets and corresponding valuation allowance disclosures, as tax attributes related to such windfall tax benefits should not be recognized until they result in a reduction of taxes payable. The tax effected amount of gross unrealized net operating loss carryforwards, and their corresponding valuation allowances resulting from stock option exercises was $25.8 million at December 31, 2013. When realized, excess windfall tax benefits are credited to additional paid-in capital. The Company follows the with-and-without allocation approach to determine when such net operating loss carryforwards have been realized.
	Deferred income taxes have not been provided on the undistributed earnings of the Company’s foreign subsidiaries because the Company’s practice and intent is to permanently reinvest these earnings. The cumulative amount of such undistributed earnings was $0.9 million and $0.5 million at December 31, 2013 and December 31, 2012, respectively. Any future distribution of these non-U.S. earnings may subject the Company to both U.S. federal and state income taxes, as adjusted for tax credits, and foreign withholding taxes that the Company estimates would be $125,000 and $76,000 at December 31, 2013 and 2012, respectively.
	A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, 2013, 2012, and 2011 is as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	Balance at January 1	$	276		$	276		$	276
Additions for tax positions related to the current year	—			—			—
Balance at December 31	$	276		$	276		$	276
The provision for uncertain tax positions relate to business in territories outside of the United States.
The Company’s policy is to classify interest and penalties on uncertain tax positions as a component of tax expense. An insignificant amount of interest and penalties on unrecognized tax benefits were accrued during the 2013 tax year. The amount of accrued interest and penalties on unrecognized tax benefits was insignificant, as of December 31, 2013 and 2012. The Company does not expect the change in uncertain tax positions to have a material impact on its financial position, results of operations or liquidity. The recognition of previously unrecognized tax benefits on uncertain positions would result in a $0.3 million tax benefit. The Company does not expect any significant increases or decreases to its unrecognized tax benefits within the next twelve months.
The Company is subject to United States federal income tax as well as to income tax in multiple state and foreign jurisdictions, including the United Kingdom. Federal income tax returns of the Company are subject to IRS examination for the 2010 through 2013 tax years. State income tax returns are subject to examination for the 2009 through 2013 tax years. The Company finalized an IRS examination for the 2011 tax year which did not result in any material adjustments. Foreign income tax returns are subject to examination for the 2007 through 2013 tax years.

Geographic_Information

Geographic Information	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Geographic Information	'
	GEOGRAPHIC INFORMATION
	Revenue by geographic region, as determined based on the location of the Company’s clients is set forth below (in thousands):
		Years Ended December 31,
		2013		2012		2011
	Revenue
	United States	$	128,983	$	81,837	$	50,874
	United Kingdom	19,448		12,930		8,612
	All other countries	36,698		23,147		13,536
	Total revenue	$	185,129	$	117,914	$	73,022
	Revenue from clients located in the United States is presented net of a $2.5 million reduction of revenue relating to a common stock warrant issued to ADP during the year ended December 31, 2011 (See Note 11).
	Property and equipment by region is set forth below (in thousands):
		December 31,
		2013		2012
	Property and equipment, net
	United States	$	10,455	$	7,529
	United Kingdom	3,185		343
	All other countries	796		75
	Total property and equipment, net	$	14,436	$	7,947

401k_Saving_Plan

401(k) Saving Plan	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
401(k) Savings Plan	'
	401(K) SAVINGS PLAN
	The Company has a defined contribution savings plan (the “Plan”) under Section 401(k) of the Internal Revenue Code. The Plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. Company contributions to the plan may be made at the discretion of the Board of Directors. Beginning in 2012, the Plan provided for a Company match of employees’ contributions in an amount equal to 50% of an employee’s contributions up to $2,400 per year which vests over four years.
	The Company incurred approximately $0.8 million and $0.3 million of matching contribution expenses related to the Plan during the years ended December 31, 2013 and 2012, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	Leases
	The Company has various non-cancelable operating leases for its offices and its managed hosting facilities and services. These leases expire at various times through 2019. Certain lease agreements contain renewal options, rent abatement, and escalation clauses. The Company recognizes rent expense on a straight-line basis over the lease term, commencing when the Company takes possession of the property. Certain of the Company’s office leases entitle the Company to receive a tenant allowance from the landlord. The Company records tenant allowances as a deferred rent credit, which the Company amortizes on a straight-line basis, as a reduction of rent expense, over the term of the underlying lease. Total rent expense under operating leases was approximately $4.1 million, $3.2 million, $1.9 million for the years ended December 31, 2013, 2012 and 2011, respectively. The Company finances the purchase of equipment under capital lease arrangements and other debt arrangements (See Note 9).
	Future minimum lease payments under non-cancelable operating and capital leases at December 31, 2013 are as follows (in thousands):
		Operating Leases		Capital Leases
	2014	$	4,938	$	943
	2015	5,042		217
	2016	5,365		4
	2017	5,511		—
	2018	5,512		—
	Thereafter	410		—
	Total minimum lease payments	$	26,778	1,164
	Less: Amounts representing interest			(41		)
	Present value of capital lease obligations			1,123
	Less: Current portion			(905		)
	Long-term portion of capital lease obligations			$	218
	Letters of Credit
	During 2013, the Company amended a standby letter of credit in association with its building lease and signed a standby letter of credit for a contractual arrangement in Israel. In addition, the Company maintains standby letters of credit in association with other contractual arrangements. Total letters of credit outstanding at December 31, 2013 was $1.5 million.
	Other Commitments
	In July 2012, the Company entered into a cloud subscription agreement with a provider of enterprise cloud computing and social enterprise solutions. The Company is obligated to pay remaining fees under this agreement of $0.8 million in 2014 and $1.0 million in 2015.
	As of December 31, 2013, the Company had agreements with various third party service providers whereby the Company has committed to assign certain dollar amounts or hours of professional service projects related to implementation and other services for clients of the Company's core solution. In aggregate, these estimated commitments total approximately $15.3 million in 2014, $15.2 million in 2015, $3.8 million in each of 2016, 2017 and 2018, and $3.5 million thereafter.
	Guarantees and Indemnifications
	The Company has made guarantees and indemnities under which it may be required to make payments to a guaranteed or indemnified party, in relation to certain transactions, including revenue transactions in the ordinary course of business. In connection with certain facility leases, the Company has agreed to indemnify its lessors for certain claims arising from the facility or the lease. The Company is obligated to indemnify its directors and officers to the maximum extent permitted under the laws of the State of Delaware. However, the Company has a directors and officers insurance policy that may reduce its exposure in certain circumstances and may enable it to recover a portion of future amounts that may be payable, if any. The duration of the guarantees and indemnities varies and, in many cases, is indefinite but subject to statutes of limitations. To date, the Company has made no payments related to these guarantees and indemnities. The Company estimates the fair value of its indemnification obligations as insignificant based on this history and the Company’s insurance coverage and therefore has not recorded any liability for these guarantees and indemnities in the accompanying consolidated balance sheets.
	Litigation
	During 2012, the Company received an unfavorable ruling in arbitration related to an employment matter. Based on this ruling, the Company has estimated the probable loss for this matter, including both the award and estimated plaintiff attorneys' fees, to be approximately $2.6 million and accrued this amount within other current liabilities. The Company determined that insurance recovery for this loss is probable, and has recorded a related receivable in other current assets for this matter. Based on the above, the Company believes this matter will not have a material adverse effect on the Company's business, operating results, cash flows or financial condition.
	The Company is subject to various legal proceedings and claims that arise in the ordinary course of business. If the Company determines that it is probable that a loss has been incurred and the amount is reasonably estimable, the Company will record a liability. Except for the matter described above, the Company has determined that it does not have a potential liability related to any legal proceedings or claims that would individually or in the aggregate materially adversely affect its financial conditions or operating results.
	Taxes
	From time to time, various federal, state and other jurisdictional tax authorities undertake review of the Company and its filings. In evaluating the exposure associated with various tax filing positions, the Company accrues charges for possible exposures. The Company believes any adjustments that may ultimately be required as a result of any of these reviews will not be material to its consolidated financial statements.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	RELATED PARTY TRANSACTIONS
	In 2010, the Cornerstone OnDemand Foundation, or the Foundation, was formed to empower communities in the United States and Internationally by increasing the impact of the non-profit sector through the utilization of talent management technology including our core solution and strategies. The Company’s CEO is on the Board of Directors of the Foundation. The Company does not direct the Foundation’s activities, and accordingly, the Company does not consolidate the Foundation’s statement of activities with its financial results. During the current year, the Company has provided at no charge certain resources to the Foundation, with approximate value of $1.3 million.
	During June 2010, an executive officer of an accounting software company joined the Company’s Board of Directors. During May 2012, an executive officer of a travel and expense management software company joined the Company's Board of Directors. For the years ended December 31, 2013, 2012 and 2011, the Company recorded $0.5 million, $0.3 million and $0.1 million, respectively, in expenses related to the use of the accounting and travel and expense software from companies whose executive officers serve on the Company's Board of Directors.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	SUBSEQUENT EVENTS
	On January 1, 2014, shares issuable under the Company’s 2010 Employee Stock Purchase Plan increased by 524,699 shares and shares issuable under the Company’s 2010 Plan increased by 2,361,145 shares in accordance with the automatic annual increase provisions of such plans. No shares have been issued under the 2010 Employee Stock Purchase Plan.
	During January and February 2014, the Board of Directors granted stock options to purchase 284,670 shares of common stock at a weighted-average exercise price of $55.51 per share. The stock options vest over four years. During January and February 2014, the Board of Directors granted restricted stock units for 10,500 shares of common stock which vest over annually over four years.

Selected_Quarterly_Data_Unaudi

Selected Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Selected Quarterly Data (Unaudited)	'
	SELECTED QUARTERLY DATA (UNAUDITED)
	The following unaudited quarterly consolidated statements of operations for each of the quarters in the years ended December 31, 2013 and 2012 have been prepared on a basis consistent with the Company’s audited annual financial statements and include, in the opinion of management, all normal recurring adjustments necessary for the fair statement of the financial information contained in these statements.
	Quarter Ended
		(in thousands, except per share data)
		Mar. 31,			June 30,			Sept. 30,			Dec. 31,			Mar. 31,			June 30,			Sept. 30,			Dec. 31,
		2012			2012			2012			2012			2013			2013			2013			2013
	Revenue	$	24,002		$	26,718		$	30,768		$	36,426		$	37,657		$	44,346		$	48,270		$	54,856
	Cost of revenue	6,844			7,890			9,135			10,722			11,252			13,164			13,644			15,488
	Gross profit	17,158			18,828			21,633			25,704			26,405			31,182			34,626			39,368
	Operating expenses:
	Sales and marketing	16,237			17,422			18,624			21,280			23,010			26,274			28,601			31,852
	Research and development	3,093			3,431			4,101			4,261			4,419			5,232			5,716			5,893
	General and administrative	5,954			5,792			6,600			7,566			8,566			7,530			8,261			9,215
	Amortization of certain acquired intangible assets	—			237			251			251			251			251			251			251
	Total operating expenses	25,284			26,882			29,576			33,358			36,246			39,287			42,829			47,211
	Loss from operations	(8,126		)	(8,054		)	(7,943		)	(7,654		)	(9,841		)	(8,105		)	(8,203		)	(7,843		)
	Other income (expense):
	Interest income (expense) and other income (expense), net	96			(514		)	18			(2		)	(92		)	(714		)	(2,747		)	(3,009		)
	Loss before income tax (provision) benefit	(8,030		)	(8,568		)	(7,925		)	(7,656		)	(9,933		)	(8,819		)	(10,950		)	(10,852		)
	Income tax (provision) benefit	(82		)	334			298			239			(1		)	136			(104		)	97
	Net loss	$	(8,112	)	$	(8,234	)	$	(7,627	)	$	(7,417	)	$	(9,934	)	$	(8,683	)	$	(11,054	)	$	(10,755	)
	Net loss per share, basic and diluted	$	(0.16	)	$	(0.17	)	$	(0.15	)	$	(0.15	)	$	(0.20	)	$	(0.17	)	$	(0.21	)	$	(0.21	)
	Weighted average common shares outstanding, basic and diluted	49,384			49,763			50,163			50,486			50,798			51,153			51,544			52,185

Investments

Investments	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Investments	'
	5. INVESTMENTS
	The Company’s investments in available-for-sale marketable securities are made within the guidelines of its investment policy, which has established guidelines relative to the diversification of the Company’s investments and their maturities, with the principle objective of capital preservation and maintaining liquidity that is sufficient to meet cash flow requirements.
	The following is a summary of investments, including cash equivalents, as of December 31, 2013 (in thousands):
		31-Dec-13
		Amortized Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
	Money market funds	$	65,700	$	—	$	—		$	65,700
	Corporate bonds	78,488		121		—			78,609
	Agency bonds	121,307		14		(5		)	121,316
		$	265,495	$	135	$	(5	)	$	265,625
	The Company’s investment in marketable securities had a weighted-average maturity date of approximately seven months. Unrealized gains and losses on investments were not significant, and the Company does not believe the unrealized losses represent other-than-temporary impairments as of December 31, 2013.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

'

Basis of Consolidation

'

Basis of Consolidation

The accompanying consolidated financial statements include the accounts of Cornerstone OnDemand, Inc., and its wholly owned subsidiaries. All significant inter-company transactions and balances have been eliminated in consolidation.

Use of Estimates

'

Use of Estimates

The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.

On an on-going basis, management evaluates its estimates, including among others those related to: (i) the realization of tax assets and estimates of tax liabilities, (ii) the recognition and disclosure of contingent liabilities, (iii) the collectability of accounts receivable, (iv) the evaluation of revenue recognition criteria, including the determination of standalone value and estimates of the selling price of multiple-deliverables in the Company’s revenue arrangements, (v) fair values of investments in marketable securities, (vi) the assigned value of acquired assets and assumed liabilities in business combinations, (vii) the useful lives of property and equipment, capitalized software and intangible assets, (viii) impairment of long-lived assets, including goodwill, (ix) the amount and period of amortization of the commission payments to record to expense in proportion to the revenue that is recognized, and (x) assumptions used in the Black-Scholes option pricing model to determine the fair value of stock options and warrants. These estimates are based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. The Company engages third-party valuation specialists to assist with the allocation of the purchase price in business combinations and, prior to the Company's IPO in March 2011, the Company engaged third-party valuation specialists to assist with estimates related to the valuation of its preferred and common stock. Such estimates required the selection of appropriate valuation methodologies and models, and significant judgment in evaluating ranges of assumptions and financial inputs.

Reclassification, Policy

'

Reclassifications

Certain amounts in the consolidated cash flows at December 31, 2012 have been reclassified to conform to the current year presentation.

Business Combinations

'

Business Combinations

The results of businesses acquired in a business combination are included in the Company’s consolidated financial statements from the date of the acquisition. Purchase accounting results in assets and liabilities of an acquired business being recorded at their estimated fair values on the acquisition date. Any excess consideration over the fair value of assets acquired and liabilities assumed is recognized as goodwill.

The Company performs valuations of assets acquired and liabilities assumed for an acquisition and allocates the purchase price to its respective net tangible and intangible assets. Determining the fair value of assets acquired and liabilities assumed requires management to use significant judgment and estimates including the selection of valuation methodologies, estimates of future revenue and cash flows, discount rates and selection of comparable companies. The Company engages the assistance of valuation specialists in concluding on fair value measurements in connection with fair values of assets and liabilities assumed in a business combination.

Transaction costs associated with business combinations are expensed as incurred, and are included in general and administrative expenses in the consolidated statement of operations. There were no transaction costs for the year ended December 31, 2013. Transaction costs were $0.7 million for the year ended December 31, 2012.

Net Loss per Share Attributable to Common Stockholders

'

Net Loss per Share Attributable to Common Stockholders

Basic net loss per share of common stock is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for a period.

Prior to the Company’s IPO in March 2011, as the Company had convertible preferred stock outstanding, and, as the holders of the Company’s convertible preferred stock were entitled to participate in dividends and earnings of the Company, the Company used the two-class method in calculating earnings per share for periods in which the Company generated net income. As the holders of the Company’s convertible preferred stock were not contractually obligated to share in the losses of the Company, no such allocation was made for any periods presented given the Company’s net losses.

The Company may grant restricted stock under the 2010 Equity Incentive Plan (“2010 Plan”) (See Note 12). As the holders of the Company’s restricted stock under the 2010 Plan are both entitled to participate in dividends and earnings of the Company, the Company uses the two-class method in calculating earnings per share for periods in which the Company generates income. As restricted stock holders are not contractually obligated to share in the losses, no such allocation was made for any periods presented given the company’s net losses.

The two-class method requires net income to be allocated between the classes of stockholders, whether vested or unvested, based on their respective rights to receive dividends, whether or not declared.

Diluted loss per share attributable to common stockholders is based on the weighted-average number shares of common stock outstanding adjusted for the dilutive effect of share-based awards and the potential dilutive effect of warrants, convertible notes and convertible preferred stock. Diluted loss per share attributable to common stockholders is the same as basic loss per share attributable to common stockholders for all periods presented because the Company has reported net losses and the effects of including the potentially dilutive items were anti-dilutive.

Revenue Recognition

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Revenue Recognition

The Company derives its revenue from the following sources:

•

Subscriptions to the Company’s solutions—Clients pay subscription fees for access to the Company's solutions for a specified period of time, typically three years for the Company's core solution or monthly, annually, or three-year periods for the Company's CSB and Cornerstone for Salesforce solutions. Fees are based on a number of factors, including the number of users having access to a solution. The Company generally recognizes revenue from subscriptions ratably over the term of the agreement.

•

Consulting services—The Company offers its clients assistance in implementing its solutions and optimizing their use. Consulting services include application configuration, system integration, business process re-engineering, change management, and training services. Services are billed either on a time-and-material or a fixed-fee basis. These services are generally purchased as part of a subscription arrangement and are typically performed within the first several months of the arrangement. Clients may also purchase consulting services at any other time. Consulting services are performed by the Company directly or by third-party professional service providers the Company engages. Clients may also choose to perform these services themselves or engage their own third-party service providers. The Company generally recognizes revenue from fixed fee consulting services using the proportional performance method over the period the services are performed and as time is incurred for time-and-material arrangements.

•

E-learning content—The Company resells third-party on-line training content, referred to as e-learning content, to its clients. In addition, the Company also hosts other e-learning content provided by its clients. The Company generally recognizes revenue from the resale of e-learning content as it is delivered and recognizes revenue from hosting as the hosting services are provided.

The Company recognizes revenue when: (i) persuasive evidence of an arrangement for the sale of the Company's solutions or consulting services exists, (ii) the solutions have been made available or delivered, or services have been performed, (iii) the sales price is fixed or determinable, and (iv) collectability is reasonably assured. The timing and amount the Company recognizes as revenue is determined based on the facts and circumstances of each client arrangement. Evidence of an arrangement consists of a signed client agreement. The Company considers that delivery of a solution has commenced once it provides the client with log-in information to access and use the solution. If non-standard acceptance periods or non-standard performance criteria exist, revenue recognition commences upon the satisfaction of the non-standard acceptance or performance criteria, as applicable. Standard acceptance or performance clauses relate to the Company’s solutions meeting certain perfunctory operating thresholds. Fees are fixed based on stated rates specified in the client agreement. If collectability is not considered reasonably assured, revenue is deferred until the fees are collected. The majority of client arrangements include multiple deliverables, such as subscriptions to the Company’s software solutions and consulting services. The Company therefore recognizes revenue in accordance with the guidance for arrangements with multiple deliverables under Accounting Standards Update (“ASU”) 2009-13 “Revenue Recognition (Topic 605)—Multiple-Deliverable Revenue Arrangements—a Consensus of the Emerging Issues Task Force,” or ASU 2009-13. As clients do not have the right to the underlying software code for the solutions, the Company’s revenue arrangements are outside the scope of software revenue recognition guidance. The Company’s agreements generally do not contain any cancellation or refund provisions other than in the event of the Company’s default.

For multiple-deliverable revenue arrangements, the Company first assesses whether each deliverable has value to the client on a standalone basis. The Company has determined that the solutions have standalone value, because, once access is given to a client, the solutions are fully functional and do not require any additional development, modification or customization. Consulting services have standalone value because third-party service providers, distributors or clients themselves can perform these services without the Company’s involvement. The consulting services assist clients with the configuration and integration of the Company’s solutions. The performance of these services generally does not require highly specialized or skilled individuals and are not essential to the functionality of the solutions.

Based on the standalone value of the deliverables, and since clients do not have a general right of return relative to the included consulting services, the Company allocates revenue among the separate deliverables in an arrangement under the relative selling price method using the selling price hierarchy established in ASU 2009-13. This hierarchy requires the selling price of each deliverable in a multiple deliverable arrangement to be based on, in descending order: (i) vendor-specific objective evidence of fair value (“VSOE”), (ii) third-party evidence of fair value (“TPE”) or (iii) management’s best estimate of the selling price (“BESP”).

The Company is generally not able to determine VSOE or TPE for its deliverables, because the deliverables are sold separately and within a sufficiently narrow price range only infrequently, and because management has determined that there are no third-party offerings reasonably comparable to the Company’s solutions. Accordingly, the selling prices of subscriptions to the solutions and consulting services is based on BESP. The determination of BESP requires the Company to make significant estimates and judgments. The Company considers numerous factors, including the nature of the deliverables themselves; the geography, market conditions and competitive landscape for the sale; internal costs; and pricing and discounting practices. The determination of BESP is made through consultation with and formal approval by senior management. The Company updates its estimates of BESP on an ongoing basis as events and as circumstances may require.

After the fair value of revenue allocable to each deliverable in a multiple deliverable arrangement based on the relative selling price method is determined, revenue is recognized for each deliverable based on the type of deliverable. For subscriptions to the solutions, revenue is recognized on a straight-line basis over the subscription term, which is typically three years. For consulting services, revenue is recognized using the proportional performance method over the period the services are performed.

In a limited number of cases, multiple deliverable arrangements may include consulting services that do not have value on a standalone basis separate from a solution, such as when the client’s intended use of a solution requires enhancements to its underlying features and functionality. In these cases, revenue is recognized as one unit of accounting on a straight-line basis from the point at which the consulting services that do not have value on a standalone basis have been completed and accepted by the client, through the remaining term of the agreement.

For arrangements in which the Company resells third-party e-learning training content to clients or hosts client or third-party e-learning training content provided by the client, revenue is recognized in accordance with accounting guidance as to when to report gross revenue as a principal or report net revenue as an agent. The Company recognizes third-party content revenue at the gross amount invoiced to clients when (i) the Company is the primary obligor, (ii) the Company has latitude to establish the price charged, and (iii) the Company bears the credit risk in the transaction. For arrangements involving the sale of third-party content, clients are charged for the content based on pay-per-use or a fixed rate for a specified number of users, and revenue is recognized at the gross amount invoiced as the content is delivered. For arrangements where clients purchase third-party content directly from a third-party vendor, or provide it themselves, and the Company integrates the content into a solution, the Company charges a fee per user or fee based on estimated bandwidth. In such cases, the fees are recognized at the net amount charged by the Company for hosting services as the content is delivered.

Revenue generated from sales arrangements through distributors, including revenue generated through the Company’s five-year global distributor agreement with ADP described below, is recognized in accordance with the Company’s revenue recognition policies as described above at the amount invoiced to the distributor. In these arrangements, the Company recognizes revenue in accordance with accounting guidance as to when to report gross revenue as a principal and when to report net revenue as an agent. The Company recognizes revenue at the net amount invoiced to the distributor, as opposed to the gross amount the distributor invoices their end customer, as the Company has determined that (i) the Company in not the primary obligor in these arrangements, (ii) the Company does not have latitude to establish the price charged to the end-customer and (iii) the Company does not bear the credit risk in the transaction.

In connection with a five-year global distributor agreement entered into in May 2009 with a global distributor, ADP, the Company entered into a warrant agreement to provide additional incentives to ADP. In April 2012, the Company signed an amendment to extend the term of the distributor agreement through 2017. The warrant agreement provided that ADP was eligible to earn fully vested and immediately exercisable ten-year warrants to purchase between zero and 886,096 shares of the Company’s common stock at a price of $0.53 per share if ADP met specified sales targets for each contract year until the earlier of the completion of the five-year term of the distributor agreement or the completion of an initial public offering of the Company’s common stock. When ADP achieved the defined sales target and earned a warrant, the Company recorded the fair value of such warrant as a reduction of revenue. For the first contract year ended June 30, 2010, no reductions of revenue were recorded, based on the Company’s conclusion that the defined sales targets had not been met by ADP.

During the year ended December 31, 2011, the Company recorded a reduction of revenue of $2.5 million in connection with the issuance of warrants to ADP. The Company recorded the fair value of the warrants as reduction of revenue as the agreement provides ADP with the right to be the distributor of the Company’s services and the Company estimates that ADP will purchase additional services from the Company. See Note 11 for additional information about warrants under the ADP agreement.

The Company records amounts that have been invoiced to its clients in accounts receivable and in either deferred revenue or revenue depending on whether the revenue recognition criteria described above have been met. Deferred revenue that will be recognized during the succeeding twelve month period from the respective balance sheet date is recorded as current deferred revenue and the remaining portion is recorded as noncurrent.

Cost of Revenue

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Cost of Revenue

Cost of revenue consists primarily of costs related to hosting the Company’s solutions; personnel and related expenses, including stock-based compensation, and related expenses for network infrastructure, IT support, consulting services and on-going client support staff; payments to external service providers; amortization of capitalized software costs, developed technology and licensing fees; and referral fees. In addition, the Company allocates a portion of overhead, such as rent, IT costs, depreciation and amortization and employee benefits costs, to cost of revenue based on headcount. Costs associated with providing consulting services are recognized as incurred when the services are performed. Out-of-pocket travel costs related to the delivery of professional services are typically reimbursed by the client and are accounted for as both revenue and expense in the period in which the cost is incurred.

Commission Payments

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Commission Payments

The Company defers commissions paid to its sales force because these amounts are recoverable from the future revenue from the non-cancelable client agreements that gave rise to the commissions. Commissions are deferred on the balance sheet and are amortized to sales and marketing expense over the term of the client agreement in proportion to the revenue that is recognized. Commissions are considered direct and incremental costs to client agreements and were generally paid in the periods the Company received payment from the client under the associated client agreement. Commencing in the fourth quarter of 2012, the Company pays commissions between 45 and 75 days after execution of the client agreement.

During the years ended December 31, 2013, 2012, and 2011, the Company deferred $22.8 million, $16.1 million and $7.7 million, respectively, of commissions on the balance sheet. During the years ended December 31, 2013, 2012, and 2011, the Company amortized $15.5 million, $10.3 million and $6.5 million to sales and marketing expense, respectively. As of December 31, 2013 and 2012, deferred commissions on the Company’s consolidated balance sheets totaled $16.6 million and $9.4 million, respectively.

Research & Development

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Research & Development

Research and development expenses consist primarily of personnel and related expenses for the Company’s research and development staff, including salaries, benefits, bonuses and stock-based compensation; the cost of certain third-party service providers; and allocated overhead. Research and development expenses, other than software development costs qualifying for capitalization, are expensed as incurred. The Company's research and development expenses were $21.3 million in 2013, $14.9 million in 2012, and $10.1 million in 2011.

Advertising Costs, Policy

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Advertising

Advertising expenses for 2013, 2012, and 2011, were $2.0 million, $0.4 million, and $0.3 million, respectively, and are expensed as incurred.

Stock-based Compensation

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Stock-Based Compensation

The Company accounts for stock-based compensation awards granted to employees and directors by recording compensation expense based on the awards' estimated fair value. The Company estimates the fair value of its stock-based compensation awards as of the date of grant using the Black-Scholes option-pricing model. The resulting fair value, net of estimated forfeitures, is recognized over the period during which an employee is required to provide service in exchange for the award, usually the vesting period, which is generally four years. The Company recognizes the fair value of stock-based compensation for awards which contain only service conditions on a straight-line basis over the vesting period of the awards. The Company recognizes the fair value of stock-based compensation for awards which contain performance conditions based upon the probability of that performance condition being met, net of estimated forfeitures, using the graded vesting method. Estimated forfeitures are based upon the Company's historical experience and the Company revises its estimates, if necessary, in subsequent periods if actual forfeitures differ from initial estimates.

The Black-Scholes option pricing model requires assumptions, including estimating the value per share of the Company's common stock (for periods prior to the Company's IPO), estimated volatility, risk-free rate, expected term and estimated dividend yield. The assumptions used in calculating the fair value of stock-based compensation awards represents the Company's best estimates, based on management judgment. The Company uses the average volatility of similar publicly traded companies as an estimate for estimated volatility. The Company determines the expected term of awards which contain only service conditions using the simplified approach, in which the expected term of an award is presumed to be the mid-point between the vesting date and the expiration date of the award, as the Company does not have sufficient historical data relating to stock-option exercises. For awards granted which contain performance conditions the Company estimates the expected term based on estimates of post-vesting employment termination behavior taking into account the life of the award. The risk-free interest rate for periods within the expected or contractual life of the option, as applicable, is based on the United States Treasury yield curve in effect during the period the options were granted. The estimated dividend yield is zero, as the Company has not declared, and does not currently intend to declare, dividends in the foreseeable future.

The following information represents the weighted average of the assumptions used in the Black-Scholes option-pricing model:

For the Years Ended December 31,

2013

2012

2011

Risk-free interest rate

1.5

%

1

%

1.7

%

Expected term (in years)

6

5.8

6

Estimated dividend yield

—

%

—

%

—

%

Estimated volatility

51.5

%

53.9

%

56.9

%

Due to the full valuation allowance provided on its net deferred tax assets, the Company has not recorded any tax benefit attributable to stock-based compensation expense as of December 31, 2013 and 2012.

Capitalized Software Costs

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Capitalized Software Costs

The Company capitalizes the costs associated with software developed or obtained for internal use, including costs incurred in connection with the development of the solutions, when the preliminary project stage is completed, management has decided to make the project a part of its future offering, and the software will be used to perform the function intended. These capitalized costs include external direct costs of materials and services consumed in developing or obtaining internal-use software, personnel and related expenses for employees who are directly associated with and who devote time to internal-use software projects and, when material, interest costs incurred during the development. Capitalization of these costs ceases once the project is substantially complete and the software is ready for its intended purpose. Costs incurred for upgrades and enhancements to the solutions are also capitalized. Post-configuration training and maintenance costs are expensed as incurred. Capitalized software costs are amortized to cost of revenue using the straight-line method over an estimated useful life of the software of three years, commencing when the software is ready for its intended use. The Company does not transfer ownership of, or lease its software to its clients.

During the years ended December 31, 2013, 2012 and 2011, the Company capitalized $7.9 million, $5.7 million, and $3.3 million, respectively, of software development costs to the balance sheet. During the years ended December 31, 2013, 2012 and 2011, the Company amortized $4.3 million, $2.8 million, and $1.9 million to cost of revenue, respectively. Based on the Company’s capitalized software costs at December 31, 2013, estimated amortization expense of $5.0 million, $3.7 million, $1.8 million and $0.2 million is expected to be recognized in 2014, 2015, 2016 and 2017, respectively.

Warrants to Purchase Common and Preferred Stock

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Warrants to Purchase Common and Preferred Stock

Warrants to Purchase Common Stock

The Company has issued warrants to purchase common stock in connection with debt arrangements and the purchase of certain domain names and has accounted for these warrants in stockholders’ equity at fair value upon issuance, based on the specific terms of such warrant arrangements.

In addition, in connection with a five-year global distributor agreement with ADP entered into in May 2009, the Company entered into a warrant agreement to provide additional incentives to ADP. See Note 11 for additional information about warrants under the ADP agreement.

Warrants to Purchase Preferred Stock

The Company issued warrants to purchase preferred stock in connection with debt arrangements and preferred stock financings and accounted for these warrants as liabilities at fair value at the time of issuance, because the underlying shares of convertible preferred stock were redeemable or contingently redeemable, including in the case of a deemed liquidation, which may have obligated the Company to transfer assets to the warrant holders. The preferred stock warrants were recorded at fair value at the time of issuance. Changes in the fair value of the preferred stock warrants each reporting period were recorded as part of other expense in the Company’s statement of operations until the earlier of: (i) the exercise or expiration of the warrants; or (ii) the completion of an initial public offering. Upon the completion of the Company's IPO, all the warrants to purchase preferred stock expired, with the exception of warrants to purchase 140,625 shares of Series D preferred stock and warrants to purchase 380,000 shares of Series C preferred stock. These remaining warrants automatically became warrants to purchase common stock and were classified as equity. Prior to the completion of the Company’s IPO in March 2011, all warrants to purchase preferred stock were exercised. The fair value of the preferred stock warrants was estimated using the Black-Scholes option-pricing model.

Comprehensive Income, Policy

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Comprehensive Loss

Comprehensive loss encompasses all changes in equity other than those arising from transactions with stockholders, and consists of net loss, currency translation adjustments and unrealized gains or losses on investments. For the years ended December 31, 2013, 2012 and 2011, accumulated other comprehensive income (loss) comprised a cumulative translation adjustment. For the year ended December 31, 2013, accumulated other comprehensive income also included net unrealized gains on investments.

Income Taxes

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Income Taxes

The Company uses the liability method of accounting for income taxes. Under the liability method, deferred taxes are determined based on the temporary differences between the financial statement and tax basis of assets and liabilities, using tax rates expected to be in effect during the years in which the bases differences are expected to reverse. A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized. In determining the need for valuation allowances, the Company considers projected future taxable income and the availability of tax planning strategies. The Company has recorded a full valuation allowance to reduce its United States and United Kingdom net deferred tax assets to zero, as it has determined that it is not more likely than not that any of the Company’s deferred tax assets will be realized.

The Company has assessed its income tax positions and recorded tax benefits for all years subject to examination, based upon its evaluation of the facts, circumstances and information available at each period end. For those tax positions where the Company has determined there is a greater than 50% likelihood that a tax benefit will be sustained, the Company has recorded the largest amount of tax benefit that may potentially be realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where it is determined there is less than 50% likelihood that a tax benefit will be sustained, no tax benefit has been recognized.

Cash and Cash Equivalents

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Cash and Cash Equivalents

The Company considers cash and cash equivalents to include short-term, highly liquid investments that are readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in the value, including investments with original or remaining maturities from the date of purchase of three months or less. At December 31, 2013 and 2012, cash and cash equivalents consisted of cash balances of $43.9 million and $24.9 million, respectively, and money market funds backed by United States Treasury Bills of $65.7 million and $51.5 million, respectively.

Investments in Marketable Securities

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Investments in Marketable Securities

The Company’s available-for-sale investments in marketable securities are recorded at fair value, with any unrealized gains and losses, net of taxes, reported as a component of stockholders’ equity until realized or until a determination is made that an other-than-temporary decline in market value has occurred. If the Company determines that an other-than-temporary decline has occurred for debt securities that the Company does not then currently intend to sell, the Company recognizes the credit loss component of an other-than-temporary impairment in other income (expense) and the remaining portion in other comprehensive income (loss). The credit loss component is identified as the amount of the present value of cash flows not expected to be received over the remaining term of the security, based on cash flow projections. In determining whether an other-than-temporary impairment exists, the Company considers: (i) the length of time and the extent to which the fair value has been less than cost; (ii) the financial condition and near-term prospects of the issuer of the securities; and (iii) the Company’s intent and ability to retain the security for a period of time sufficient to allow for any anticipated recovery in fair value. The cost of marketable securities sold is determined based on the specific identification method and any realized gains or losses on the sale of investments are reflected as a component of interest income or expense. In addition, the Company classifies marketable securities as current or non-current based upon the maturity dates of the securities. At December 31, 2013, the Company had $199.9 million of short-term investments in marketable securities. The Company had no investments in marketable securities at December 31, 2012.

Restricted Cash

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Restricted Cash

Included in current and non-current other assets at December 31, 2013 and 2012 were restricted cash of $0.2 million and $0.1 million, respectively, in relation to a standby letter of credit in British Pounds for a foreign sales arrangement with a customer in the United Kingdom.

Allowance for Doubtful Accounts

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Allowance for Doubtful Accounts

The Company bases its allowance for doubtful accounts on its historical collection experience and a review in each period of the status of the then-outstanding accounts receivable.

A reconciliation of the beginning and ending amount of allowance for doubtful accounts for the years ended December 31, 2013, 2012 and 2011, is as follows (in thousands):

2013

2012

2011

Beginning balance, January 1

$

464

$

153

$

32

Additions and adjustments

968

358

203

Write-offs

(411

)

(47

)

(82

)

Ending balance, December 31

$

1,021

$

464

$

153

Property and Equipment, Net

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Property and Equipment, Net

Property and equipment are recorded at historical cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method based upon the estimated useful lives of the assets, generally two to seven years (See Note 7).

The Company leases equipment under capital lease arrangements. The assets and liabilities under capital lease are recorded at the lesser of the present value of aggregate future minimum lease payments, including estimated bargain purchase options, or the fair value of the asset under lease. Assets under capital lease are depreciated using the straight-line method over the lesser of the estimated useful life of the asset or the term of the lease.

Leasehold improvements are depreciated on a straight-line basis over the shorter of their estimated useful lives or lease terms. Repair and maintenance costs are charged to expense as incurred, while renewals and improvements are capitalized.

Impairment of Long Lived Assets

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Impairment of Long Lived Assets

The Company evaluates the recoverability of its long-lived assets with finite useful lives, including intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. Such triggering events or changes in circumstances may include: a significant decrease in the market price of a long-lived asset, a significant adverse change in the extent or manner in which a long-lived asset is being used, a significant adverse change in legal factors or in the business climate, the impact of competition or other factors that could affect the value of a long-lived asset, a significant adverse deterioration in the amount of revenue or cash flows expected to be generated from an asset group, an accumulation of costs significantly in excess of the amount originally expected for the acquisition or development of a long-lived asset, current or future operating or cash flow losses that demonstrate continuing losses associated with the use of a long-lived asset, or a current expectation that, more likely than not, a long-lived asset will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. The Company performs impairment testing at the asset group level that represents the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. If events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable and the expected undiscounted future cash flows attributable to the asset group are less than the carrying amount of the asset group, an impairment loss equal to the excess of the asset’s carrying value over its fair value is recorded. Fair value is determined based upon estimated undiscounted future cash flows. There were no impairment charges related to identifiable long lived assets in the years ended December 31, 2013 and 2012.

Intangible Assets

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Intangible Assets

Identifiable intangible assets primarily consist of trade names and intellectual property and acquisition-related intangibles, including developed technology, customer relationships, non-compete agreements, trade names and trademarks. The Company determines the appropriate useful life of its intangible assets by performing an analysis of expected cash flows of the acquired assets. Intangible assets are amortized over their estimated useful lives ranging from two to ten years, generally using the straight line method which approximates the pattern in which the economic benefits are consumed.

Goodwill

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Goodwill

Goodwill is not amortized, but instead is required to be tested for impairment annually and under certain circumstances. The Company performs such testing of goodwill in the fourth quarter of each year, or as events occur or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. Events or changes in circumstances which could trigger an impairment review include a significant adverse change in legal factors or in the business climate, an adverse action or assessment by a regulator, unanticipated competition, a loss of key personnel, significant changes in the manner of the Company’s use of the acquired assets or the strategy for the Company’s overall business, significant negative industry or economic trends, or significant underperformance relative to expected historical or projected future results of operations.

As part of the annual impairment test, the Company may conduct an assessment of qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the Company determines that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, it then conducts the first step of a two-step impairment test. The first step of the test for goodwill impairment compares the fair value of the applicable reporting unit with its carrying value. Fair value is determined using a discounted cash flow method and/or prevailing earnings multiples for the reporting unit. The use of discounted cash flows requires the use of various economic, market and business assumptions in developing the reporting unit’s revenue, cost and cash flow forecasts, the useful life over which cash flows will occur, and determination of the reporting unit’s weighted average cost of capital that reflect the Company’s best estimates when performing the annual impairment test.

If the fair value of a reporting unit is less than the reporting unit’s carrying value, the Company performs the second step of the test for impairment of goodwill in which the Company compares the implied fair value of the reporting unit’s goodwill with the carrying value of that goodwill. The estimate of implied fair value of goodwill may require valuations of certain internally generated and unrecognized intangible assets and other assets and liabilities. If the carrying value of the goodwill exceeds the calculated implied fair value, the excess amount will be recognized as an impairment loss. Based on the results of the annual impairment test, no impairment of goodwill existed at December 31, 2013.

Fair Value of Financial Instruments

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Fair Value of Financial Instruments

Fair value represents the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy is based on the following three levels of inputs, of which the first two are considered observable and the last one is considered unobservable:

•

Level 1—Quoted prices (unadjusted) in active markets for identical assets or liabilities that management has the ability to access at the measurement date.

•

Level 2—Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

•

Level 3—Unobservable inputs.

Observable inputs are based on market data obtained from independent sources.

Accretion of Preferred Stock

'

Accretion of Preferred Stock

Prior to the completion of the Company's IPO in March 2011, the Company accreted the Series D and Series E preferred stock carrying values to their estimated redemption values over the period to their earliest redemption date, May 10, 2014, using the interest rate method. Upon the completion of the Company's IPO, all of the Series D and Series E preferred stock converted to common stock and redemption rights to the preferred stockholders were removed. For the year ended December 31, 2011, the Company recorded accretion of $5.2 million.

Concentration of Risk

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Concentration of Risk

Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash, cash equivalents, restricted cash, and accounts receivable. The Company’s cash and cash equivalents are deposited with several financial institutions which, at times, may exceed federally insured limits, as applicable.

Accounts receivable include amounts due from clients with principal operations primarily in the United States. The Company performs ongoing credit evaluations of its clients.

For the years ended December 31, 2013, 2012 and 2011, no single client comprised more than 10% of the Company’s revenue. No single client had an accounts receivable balance greater than 10% of total accounts receivable at December 31, 2013 or 2012.

Foreign Currency Transactions and Translation

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Foreign Currency Transactions and Translation

Transactions in foreign currencies are translated into U.S. Dollars at the rates of exchange in effect at the date of the transaction. Transaction gains (losses) were approximately $(0.3) million, $0.2 million and $(0.5) million for the years ended December 31, 2013, 2012 and 2011, respectively, and are included in other, net within other income (expense), net, in the accompanying consolidated statements of operations.

The Company has entities in various countries. For entities where the local currency is different than the functional currency, the local currency financial statements have been remeasured from the local currency into the functional currency using the current exchange rate for monetary accounts and historical exchange rates for nonmonetary accounts, with exchange differences on remeasurement included in other income (loss). To the extent that the functional currency is different than the U.S Dollar, the financial statements have then been translated into U.S. Dollars using period-end exchanges rates for assets and liabilities and average exchanges rates for the results of operations. Foreign currency translation gains and losses are included as a component of accumulated other comprehensive income or loss in the consolidated balance sheets.

Recent Accounting Pronouncements

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Recent Accounting Pronouncements

In February 2013, the Financial Accounting Standards Board (“FASB”) issued a new accounting standards update amending the accounting guidance for the presentation of comprehensive income to improve the reporting of reclassifications out of accumulated other comprehensive income. The amendment requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by significant component. The new standard is effective prospectively for reporting periods beginning after December 15, 2012. The new guidance did not have a significant impact on the Company’s disclosures and does not have an impact on the Company’s results of operations or financial position.

In March 2013, the FASB issued new accounting guidance clarifying the accounting for the release of cumulative translation adjustment into net income when a company either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning on or after December 15, 2013. The Company does not anticipate that the adoption of this guidance will have a significant impact on its financial position, results of operations or cash flows.

In July 2013, the FASB issued a new accounting standards update amending the guidance related to the presentation of unrecognized tax benefits. The accounting standards update states that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The new standard is effective for annual and interim periods for fiscal years beginning after December 15, 2013, and early adoption is permitted. The new guidance is not expected to have a significant impact on the Company’s results of operations or financial position.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Schedule of Black-Scholes Option-Pricing Model Assumptions	'
	nformation represents the weighted average of the assumptions used in the Black-Scholes option-pricing model:
		For the Years Ended December 31,
		2013			2012			2011
	Risk-free interest rate	1.5	%		1	%		1.7	%
	Expected term (in years)	6			5.8			6
	Estimated dividend yield	—	%		—	%		—	%
	Estimated volatility	51.5	%		53.9	%		56.9	%
Reconciliation of Beginning and Ending Amount of Allowance for Doubtful Accounts	'
	A reconciliation of the beginning and ending amount of allowance for doubtful accounts for the years ended December 31, 2013, 2012 and 2011, is as follows (in thousands):
		2013				2012				2011
	Beginning balance, January 1	$	464			$	153			$	32
	Additions and adjustments	968				358				203
	Write-offs	(411		)		(47		)		(82		)
	Ending balance, December 31	$	1,021			$	464			$	153

Business_Acquisition_Tables

Business Acquisition (Tables)	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Allocation of Total Purchase Consideration	'
	The Company’s allocation of the total purchase consideration as of April 5, 2012 is summarized below (in thousands):
	Acquired intangible assets:
	Developed technology	$	3,800
	Customer relationships	2,400
	Non-compete agreements	610
	Domains/trademark/tradenames	320
	Total acquired intangible assets	7,130
	Goodwill	8,193
	Other assets (including cash of $76)	815
	Current liabilities	(506		)
	Deferred revenue	(427		)
	Borrowings	(557		)
	Net deferred tax liabilities	(1,809		)
	Net Assets Acquired	$	12,839
Unaudited Pro Forma Financial Information	'
	The following table reflects the unaudited pro forma consolidated results of operations as if the Sonar acquisition had taken place on January 1, 2011, after giving effect to certain adjustments including the amortization of acquired intangible assets and the associated tax effect and the elimination of the Company’s and Sonar’s non-recurring acquisition-related expenses (in thousands):
		For the Years Ended
		December 31,
		2013			2012			2011
		Actual			Pro Forma			Pro Forma
	Revenue	$	185,129		$	118,917		$	76,449
	Net loss	$	(40,426	)	$	(31,072	)	$	(65,342	)

Net_Loss_Per_Share_Attributabl1

Net Loss Per Share Attributable to Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Basic and Diluted Loss Per Share Attributable to Common Stockholders	'
	The following table presents the basic and diluted loss per share attributable to common stockholders (in thousands, except per share amounts):
		For the Years Ended December 31,
		2013				2012			2011
	Net loss attributable to common stockholders	$	(40,426	)		$	(31,390	)	$	(69,108	)
	Weighted-average shares of common stock outstanding, excluding shares issued upon early exercise of unvested options and unvested restricted stock	51,427				49,929			39,824
	Net loss per share attributable to common stockholders—basic and diluted	$	(0.79	)		$	(0.63	)	$	(1.74	)
Anti-Dilutive Shares Excluded from Calculation of Diluted Net Loss Per Share	'
	The following table presents the number of anti-dilutive shares excluded from the calculation of diluted net loss per share attributable to common stockholders (in thousands):
		December 31,
		2013			2012			2011
	Options to purchase common stock and restricted stock units	7,730			7,331			5,845
	Convertible notes	4,682			—			—
	Common stock warrants	4,682			—			130
	Shares issued for purchase consideration held in escrow	—			16			—
	Common stock subject to repurchase right	—			10			30
	Other restricted common stock	12			31			—
	Total shares excluded from net loss per share attributable to common stockholders	17,106			7,388			6,005

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Gross Carrying Value and Accumulated Amortization of Finite-Lived Intangible Assets	'
	The following table presents the gross carrying amount and accumulated amortization of finite-lived intangible assets as of December 31, 2013 and 2012 (in thousands):
		December 31, 2013							31-Dec-12
		Gross		Accumulated			Net		Gross		Accumulated			Net
		Carrying		Amortization			Carrying		Carrying		Amortization			Carrying
		Amount					Amount		Amount					Amount
	Developed technology	$	3,800	$	(1,649	)	$	2,151	$	3,800	$	(700	)	$	3,100
	Customer relationships	2,400		(1,042		)	1,358		2,400		(441		)	1,959
	Domains/trademarks/tradenames	320		(278		)	42		320		(118		)	202
	Software license rights	1,654		(759		)	895		1,654		(459		)	1,195
	Non-compete agreements	610		(424		)	186		610		(179		)	431
	Total	$	8,784	$	(4,152	)	$	4,632	$	8,784	$	(1,897	)	$	6,887
Estimated Amortization Expense for Finite-Lived Intangible Assets	'
	The following table presents the Company’s estimate of remaining amortization expense for each of the five succeeding fiscal years for finite-lived intangible assets that existed at December 31, 2013 (in thousands):
	2014	$	2,078
	2015	1,840
	2016	555
	2017	146
	2018	13
	Total	$	4,632
Changes in Carrying Amount of Goodwill	'
	The following table presents the changes in the carrying amount of goodwill for the years ended December 31, 2013 and 2012 (in thousands):
	Goodwill as of December 31, 2011	$	—
	Goodwill from Sonar acquisition, April 5, 2012	8,193
	Goodwill as of December 31, 2012	$	8,193
	Adjustments	—
	Goodwill as of December 31, 2013	$	8,193

Other_Balance_Sheet_Amounts_Ta

Other Balance Sheet Amounts (Tables)	12 Months Ended
	Dec. 31, 2013
Balance Sheet Related Disclosures [Abstract]	'
Schedule of Property and Equipment, Net	'
	The balance of property and equipment, net is as follows (in thousands):
		Useful Life		December 31,
				2013				2012
	Computer equipment and software	2 – 5 years		$	15,768			$	9,976
	Furniture and fixtures	7 years		2,265				869
	Leasehold improvements	2 – 6 years		4,190				1,520
	Renovation in progress	n/a		954				1,148
				23,177				13,513
	Less: accumulated depreciation and amortization			(8,741		)		(5,566		)
	Total property and equipment, net			$	14,436			$	7,947
Schedule of Accrued Expenses	'
	The balance of accrued expenses is as follows (in thousands):
		December 31,
		2013				2012
	Accrued bonuses	$	6,860			$	5,229
	Accrued commissions	7,246				3,826
	Other accrued expenses	8,182				5,931
	Total accrued expenses	$	22,288			$	14,986

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'
	Assets and liabilities measured at fair value on a recurring basis include the following as of December 31, 2013 and 2012 (in thousands):
		December 31, 2013											31-Dec-12
		Fair Value			Level 1			Level 2			Level 3		Fair Value		Level 1		Level 2		Level 3
	Cash equivalents	$	65,700		$	65,700		$	—		$	—	$	51,521	$	51,521	$	—	$	—
	Corporate bonds	78,609			—			78,609			—		—		—		—		—
	Agency bonds	121,316			—			121,316			—		—		—		—		—
		$	265,625		$	65,700		$	199,925		$	—	$	51,521	$	51,521	$	—	$	—
Changes in Fair Value of Preferred Stock Warrant Liability	'
	The changes in the fair value of preferred stock warrants are summarized below (in thousands):
		December 31,
		2011
	Fair value at beginning of period	$	39,756
	Changes in fair value of preferred stock warrant liabilities recorded in the statement of operations	42,559
	Exercise of preferred stock warrants	(82,315		)
	Fair value at end of period	$	—
Common Stock Warrants Outstanding	'
	The following weighted-average assumptions were used to determine the fair value of the Series C, Series D, and Series E Preferred Stock warrants at the exercise date during March 2011:
		Series C			Series D			Series E
	Risk-free interest rate	0.1		%	0.1		%	0.1		%
	Expected term (in years)	0			0			0
	Estimated dividend yield	—			—			—
	Weighted-average estimated volatility	43.1		%	43.1		%	43.1		%
	Fair value (in thousands)	$	3,905		$	56,445		$	21,965

Debt_and_Other_Financing_Arran1

Debt and Other Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Convertible Debt	'
	The net carrying amount of the liability component of the Notes as of December 31, 2013 consists of the following (in thousands):
	Principal amount	$	253,000
	Unamortized debt discount	(35,035		)
	Net carrying value	$	217,965
Maturities of Outstanding Borrowings	'
	Maturities of outstanding borrowings under the other debt arrangements as of December 31, 2013 were as follows for each year ending December (in thousands):
	2014	$	519
	2015	382
	2016	10
	Total long-term debt	$	911
Schedule of Debt Cost and Interest Expense Recognized	'
	The following table presents the interest expense recognized related to the Notes for year ended December 31, 2013 (in thousands):
		Year Ended  December 31,
		2013
	Contractual interest expense at 1.5% per annum	$	2,045
	Amortization of debt issuance costs	591
	Accretion of debt discount	3,681
	Total	$	6,317

Stock_Option_Plans_Tables

Stock Option Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Summary of stock option activity	'
	The following table summarizes the stock option activity which contain only service conditions, under the Company’s 1999, 2009 and 2010 Plans (in thousands, except per share and term information):
		Shares		Weighted			Weighted		Aggregate
				Average			Average		Intrinsic
				Exercise			Remaining		Value
				Price			Contractual
							Term
	Outstanding, December 31, 2012	6,610		$	12.49		8.2		$	112,899
	Granted	2,394		43.32
	Exercised	(1,566	)	8.58
	Forfeited	(311	)	27
	Outstanding, December 31, 2013	7,127		23.07			8.1		215,549
	Exercisable at December 31, 2013	2,890		10.46			7		123,833
	Vested and expected to vest at December 31, 2013	7,022		$	22.91		8.1		$	213,492
Schedule of stock options outstanding and exercisable by range of exercise prices	'
	The following table summarizes information about stock options, which contain only service conditions, under the Company’s equity incentive plans at December 31, 2013 (in thousands except term information):
		Options Outstanding				Options Exercisable
		at  December 31, 2013				at December 31, 2013
		Number of Options		Weighted		Number of Options		Weighted
				Average				Average
				Remaining				Remaining
				Contractual				Contractual
				Term (in				Term (in
				years)				years)
	Range of Exercise Prices
	$0.34 to $1.65	841		5.6		800		5.5
	$5.93 to $8.88	1,219		6.9		866		6.9
	$12.54 to $15.41	596		7.7		289		7.7
	$16.24 to $18.82	732		8		458		8
	$20.85 to $23.94	1,095		8.4		366		8.4
	$27.75 to $31.44	394		8.9		104		8.8
	$33.34 to $36.15	609		9.2		4		9.2
	$40.03 to $45.76	895		9.5		2		9.8
	$50.42 to $52.72	746		9.7		1		9.9
		7,127		8.1		2,890		7
Schedule of restricted stock unit activity	'
	Restricted stock unit activity for the year ended December 31, 2013 under the Company’s equity incentive plans is summarized as follows (shares in thousands):
		Number of Shares		Weighted
				Average Grant  Date
				Fair Value
	Nonvested shares subject to restricted stock units outstanding at December 31, 2012	425		$	14.37
	Granted	173		42.9
	Forfeited	(2	)	40.03
	Vested	(214	)	13.15
	Nonvested shares subject to restricted stock units outstanding at December 31, 2013	382		$	27.81
Stock-based compensation expense related to stock options, restricted stock units and restricted stock awards	'
	Stock-based compensation expense related to stock options, restricted stock units and restricted stock awards is included in the following line items in the accompanying Consolidated Statement of Operations for the years ended December 31, 2013, 2012, and 2011 (in thousands):
		Years Ended December 31,
		2013			2012			2011
	Cost of revenue	$	2,207		$	1,660		$	581
	Sales and marketing	9,866			3,982			1,121
	Research and development	2,052			949			755
	General and administrative	6,715			5,616			2,045
	Total	$	20,840		$	12,207		$	4,502

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income before Income Tax, Domestic and Foreign	'
	The components of the Company’s loss before provision (benefit) for income taxes are as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	United States	$	(36,821	)	$	(20,173	)	$	(60,300	)
	Foreign	(3,733		)	(12,006		)	(3,419		)
	Loss before provision for income taxes	$	(40,554	)	$	(32,179	)	$	(63,719	)
Components of Income Tax Expense (Benefit)	'
	The components of the provision (benefit) for income taxes attributable to continuing operations are as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	Current income tax provision:
	Federal	$	—		$	—		$	—
	State	117			—			—
	Foreign	620			176			181
	Total current income tax provision	737			176			181
	Deferred income tax benefit:
	Federal	—			—			—
	State	—			—			—
	Foreign	(865		)	(965		)	—
	Total deferred income tax benefit	(865		)	(965		)	—
	Total income tax (benefit) provision	$	(128	)	$	(789	)	$	181
Effective Income Tax Rate Reconciliation	'
	The differences in the total provision for income taxes that would result from applying the 34% federal statutory rate to loss before provision for income taxes and the reported provision for income taxes are as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	U.S. Federal tax benefit at statutory rates	$	(13,784	)	$	(10,941	)	$	(21,688	)
	State income taxes, net of federal tax benefit	(415		)	(60		)	(916		)
	Foreign rate differential	1,354			1,008			219
	Preferred stock warrant charges	—			—			14,470
	Stock based compensation	2,039			1,360			474
	Other permanent differences	410			654			188
	Other	76			(194		)	206
	Valuation allowance	10,192			7,384			7,228
	Total income tax (benefit) provision	$	(128	)	$	(789	)	$	181
Deferred Tax Assets and Liabilities	'
	Major components of the Company’s deferred tax assets (liabilities) at December 31, 2013 and 2012 are as follows (in thousands):
		December 31,
		2013			2012
	Deferred tax assets:
	Accrued expenses	$	2,029		$	1,306
	Long-lived intangible assets — basis difference	7,846			5,155
	Net operating loss carryforwards	33,823			24,392
	Stock-based compensation	4,818			2,671
	Deferred revenue	1,905			2,375
	Convertible note hedge	16,705			—
	Other	452			274
	Total deferred tax assets	67,578			36,173
	Valuation allowance	(48,558		)	(34,081		)
	Deferred tax assets, net of valuation allowance	19,020			2,092
	Deferred tax liabilities:
	Prepaid expenses and deferred commissions	(3,613		)	(2,029		)
	Long-lived fixed assets — basis difference	(2,136		)	(805		)
	Convertible note discount	(13,028		)	—
	Other	(120		)	—
	Total deferred tax liabilities	(18,897		)	(2,834		)
	Net deferred tax assets (liabilities)	$	123		$	(742	)
Unrecognized Tax Benefits Roll Forward	'
	A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, 2013, 2012, and 2011 is as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	Balance at January 1	$	276		$	276		$	276
	Additions for tax positions related to the current year	—			—			—
	Balance at December 31	$	276		$	276		$	276

Geographic_Information_Tables

Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	'
	Property and equipment by region is set forth below (in thousands):
		December 31,
		2013		2012
	Property and equipment, net
	United States	$	10,455	$	7,529
	United Kingdom	3,185		343
	All other countries	796		75
	Total property and equipment, net	$	14,436	$	7,947
	Revenue by geographic region, as determined based on the location of the Company’s clients is set forth below (in thousands):
		Years Ended December 31,
		2013		2012		2011
	Revenue
	United States	$	128,983	$	81,837	$	50,874
	United Kingdom	19,448		12,930		8,612
	All other countries	36,698		23,147		13,536
	Total revenue	$	185,129	$	117,914	$	73,022

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Future Minimum Lease Payments under Non-cancelable Operating and Capital Leases	'
	Future minimum lease payments under non-cancelable operating and capital leases at December 31, 2013 are as follows (in thousands):
		Operating Leases		Capital Leases
	2014	$	4,938	$	943
	2015	5,042		217
	2016	5,365		4
	2017	5,511		—
	2018	5,512		—
	Thereafter	410		—
	Total minimum lease payments	$	26,778	1,164
	Less: Amounts representing interest			(41		)
	Present value of capital lease obligations			1,123
	Less: Current portion			(905		)
	Long-term portion of capital lease obligations			$	218

Selected_Quarterly_Data_Unaudi1

Selected Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Schedule of Quarterly Consolidated Statements of Operations	'
	The following unaudited quarterly consolidated statements of operations for each of the quarters in the years ended December 31, 2013 and 2012 have been prepared on a basis consistent with the Company’s audited annual financial statements and include, in the opinion of management, all normal recurring adjustments necessary for the fair statement of the financial information contained in these statements.
	Quarter Ended
		(in thousands, except per share data)
		Mar. 31,			June 30,			Sept. 30,			Dec. 31,			Mar. 31,			June 30,			Sept. 30,			Dec. 31,
		2012			2012			2012			2012			2013			2013			2013			2013
	Revenue	$	24,002		$	26,718		$	30,768		$	36,426		$	37,657		$	44,346		$	48,270		$	54,856
	Cost of revenue	6,844			7,890			9,135			10,722			11,252			13,164			13,644			15,488
	Gross profit	17,158			18,828			21,633			25,704			26,405			31,182			34,626			39,368
	Operating expenses:
	Sales and marketing	16,237			17,422			18,624			21,280			23,010			26,274			28,601			31,852
	Research and development	3,093			3,431			4,101			4,261			4,419			5,232			5,716			5,893
	General and administrative	5,954			5,792			6,600			7,566			8,566			7,530			8,261			9,215
	Amortization of certain acquired intangible assets	—			237			251			251			251			251			251			251
	Total operating expenses	25,284			26,882			29,576			33,358			36,246			39,287			42,829			47,211
	Loss from operations	(8,126		)	(8,054		)	(7,943		)	(7,654		)	(9,841		)	(8,105		)	(8,203		)	(7,843		)
	Other income (expense):
	Interest income (expense) and other income (expense), net	96			(514		)	18			(2		)	(92		)	(714		)	(2,747		)	(3,009		)
	Loss before income tax (provision) benefit	(8,030		)	(8,568		)	(7,925		)	(7,656		)	(9,933		)	(8,819		)	(10,950		)	(10,852		)
	Income tax (provision) benefit	(82		)	334			298			239			(1		)	136			(104		)	97
	Net loss	$	(8,112	)	$	(8,234	)	$	(7,627	)	$	(7,417	)	$	(9,934	)	$	(8,683	)	$	(11,054	)	$	(10,755	)
	Net loss per share, basic and diluted	$	(0.16	)	$	(0.17	)	$	(0.15	)	$	(0.15	)	$	(0.20	)	$	(0.17	)	$	(0.21	)	$	(0.21	)
	Weighted average common shares outstanding, basic and diluted	49,384			49,763			50,163			50,486			50,798			51,153			51,544			52,185

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Marketable Securities	'
		31-Dec-13
		Amortized Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
	Money market funds	$	65,700	$	—	$	—		$	65,700
	Corporate bonds	78,488		121		—			78,609
	Agency bonds	121,307		14		(5		)	121,316
		$	265,495	$	135	$	(5	)	$	265,625

Organization_Details

Organization (Details)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Date of incorporation	24-May-99
State of incorporation	'Delaware
Principal operation beginning date	'1999-11

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
					security					security
Significant Accounting Policies [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Withdrawn secondary offering expense	'	'	'	'	'	'	'	'	$0	$0	$555,000
Accounting for Commission Payments	'	'	'	'	'	'	'	'	'	'	'
Commissions deferred during the period	'	'	'	'	'	'	'	'	22,800,000	16,100,000	7,700,000
Deferred commissions	16,634,000	'	'	'	9,354,000	'	'	'	16,634,000	9,354,000	'
Research and development	5,893,000	5,716,000	5,232,000	4,419,000	4,261,000	4,101,000	3,431,000	3,093,000	21,260,000	14,886,000	10,149,000
Advertising expense	'	'	'	'	'	'	'	'	2,000,000	400,000	300,000
Stock Based Compensation - Black-Scholes Option-Pricing Model Assumptions:	'	'	'	'	'	'	'	'	'	'	'
Risk-free interest rate	'	'	'	'	'	'	'	'	1.50%	1.00%	1.70%
Expected term	'	'	'	'	'	'	'	'	'6 years 0 months 11 days	'5 years 10 months 2 days	'6 years
Estimated dividend yield	'	'	'	'	'	'	'	'	0.00%	0.00%	0.00%
Estimated volatility	'	'	'	'	'	'	'	'	51.50%	53.90%	56.90%
Capitalized Software Costs	'	'	'	'	'	'	'	'	'	'	'
Capitalized software costs, estimated useful life	'	'	'	'	'	'	'	'	'3 years	'	'
Capitalized software costs, amount capitalized during the period	'	'	'	'	'	'	'	'	7,900,000	5,700,000	3,300,000
Amortization of capitalized software costs	'	'	'	'	'	'	'	'	4,300,000	2,800,000	1,900,000
Capitalized software costs, estimated amortization expense in 2014	5,000,000	'	'	'	'	'	'	'	5,000,000	'	'
Capitalized software costs, estimated amortization expense in 2015	3,700,000	'	'	'	'	'	'	'	3,700,000	'	'
Capitalized software costs, estimated amortization expense in 2016	1,800,000	'	'	'	'	'	'	'	1,800,000	'	'
Capitalized software costs, estimated amortization expense in 2017	200,000	'	'	'	'	'	'	'	200,000	'	'
Cash and Cash Equivalents	'	'	'	'	'	'	'	'	'	'	'
Cash balances	43,900,000	'	'	'	24,900,000	'	'	'	43,900,000	24,900,000	'
Money market funds backed by U.S. Treasury Bills	65,700,000	'	'	'	51,500,000	'	'	'	65,700,000	51,500,000	'
Short-term investments	199,925,000	'	'	'	0	'	'	'	199,925,000	0	'
Number of available-for-sale securities	'	'	'	'	0	'	'	'	'	0	'
Restricted cash	200,000	'	'	'	100,000	'	'	'	200,000	100,000	'
Allowance for Doubtful Accounts - Reconciliation:	'	'	'	'	'	'	'	'	'	'	'
Beginning balance, January 1	'	'	'	464,000	'	'	'	153,000	464,000	153,000	32,000
Additions and adjustments	'	'	'	'	'	'	'	'	968,000	358,000	203,000
Write-offs	'	'	'	'	'	'	'	'	-411,000	-47,000	-82,000
Ending balance, December 31	1,021,000	'	'	'	464,000	'	'	'	1,021,000	464,000	153,000
Impairment of Long Lived Assets	'	'	'	'	'	'	'	'	'	'	'
Impairment charges related to identified intangible assets	'	'	'	'	'	'	'	'	0	0	'
Intangible Assets	'	'	'	'	'	'	'	'	'	'	'
Accretion of preferred stock	'	'	'	'	'	'	'	'	'	'	5,200,000
Minimum	'	'	'	'	'	'	'	'	'	'	'
Accounting for Commission Payments	'	'	'	'	'	'	'	'	'	'	'
Commission payment period	'	'45 days	'	'	'	'	'	'	'	'	'
Intangible Assets	'	'	'	'	'	'	'	'	'	'	'
Identified intangible assets amortization period	'	'	'	'	'	'	'	'	'2 years	'	'
Maximum	'	'	'	'	'	'	'	'	'	'	'
Accounting for Commission Payments	'	'	'	'	'	'	'	'	'	'	'
Commission payment period	'	'75 days	'	'	'	'	'	'	'	'	'
Intangible Assets	'	'	'	'	'	'	'	'	'	'	'
Identified intangible assets amortization period	'	'	'	'	'	'	'	'	'10 years	'	'
General and administrative	'	'	'	'	'	'	'	'	'	'	'
Significant Accounting Policies [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Acquisition related costs	'	'	'	'	'	'	'	'	0	700,000	'
Sales and marketing	'	'	'	'	'	'	'	'	'	'	'
Accounting for Commission Payments	'	'	'	'	'	'	'	'	'	'	'
Amortization of deferred commissions	'	'	'	'	'	'	'	'	15,500,000	10,300,000	6,500,000
Other income (expense), net	'	'	'	'	'	'	'	'	'	'	'
Intangible Assets	'	'	'	'	'	'	'	'	'	'	'
Foreign currency transactions and translation	'	'	'	'	'	'	'	'	($300,000)	$200,000	($500,000)
Revenue | Customer concentration risk	'	'	'	'	'	'	'	'	'	'	'
Intangible Assets	'	'	'	'	'	'	'	'	'	'	'
Number of major customers	'	'	'	'	'	'	'	'	0	0	0
Concentration Risk, Percentage	'	'	'	'	'	'	'	'	10.00%	10.00%	10.00%
Accounts receivable | Customer concentration risk	'	'	'	'	'	'	'	'	'	'	'
Intangible Assets	'	'	'	'	'	'	'	'	'	'	'
Number of major customers	'	'	'	'	'	'	'	'	0	0	'
Concentration Risk, Percentage	'	'	'	'	'	'	'	'	10.00%	10.00%	'

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Warrants, Preferred and Common Stock (Details) (USD $)	12 Months Ended				0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2011	6-May-09	Mar. 31, 2011	Mar. 31, 2011	6-May-09	6-May-09
				Common Stock	Common Stock	Series D Preferred Stock	Series C Preferred Stock	Minimum	Maximum
				Ten-year Distributor Incentive Warrants	Warrants Issued on May 6, 2009			Common Stock	Common Stock
					Ten-year Distributor Incentive Warrants			Warrants Issued on May 6, 2009	Warrants Issued on May 6, 2009
								Ten-year Distributor Incentive Warrants	Ten-year Distributor Incentive Warrants
Class of Warrant or Right [Line Items]	'	'	'	'	'	'	'	'	'
Preferred Stock, Accretion of Redemption Discount	'	'	$5,200,000	'	'	'	'	'	'
Class of Warrant or Right, Warrants or Rights Exercisable Period	'	'	'	'	'10 years	'	'	'	'
Number of shares purchasable upon warrant exercise	4,700,000	'	'	'	'	140,625	380,000	0	886,096
Warrants exercise price (in usd per share)	80.06	'	'	'	0.53	'	'	'	'
Change In Fair Value Of Warrant	$0	$0	($2,500,000)	($2,500,000)	'	'	'	'	'

Business_Acquisition_Additiona

Business Acquisition - Additional Information (Details) (USD $)

3 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Apr. 05, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Apr. 05, 2012

Dec. 31, 2013

Dec. 31, 2012

General and administrative

General and administrative

Sonar Limited

Sonar Limited

Sonar Limited

Sonar Limited

Sonar Limited

Sonar Limited

Sonar Limited

Sonar Limited

Sonar Limited

Employee

Developed technology

Customer relationships

Non-compete agreements

Domains/trademarks/tradenames

Common Stock

Restricted stock awards

General and administrative

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business acquisition, cash paid

'

'

'

'

'

'

'

'

'

'

'

'

'

$12,500,000

'

'

'

'

'

'

'

'

Common stock issued for business acquisition (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,530

31,164

'

Fair value of common stock issued for business acquisition

'

'

'

'

'

'

'

'

'

'

'

'

'

300,000

'

'

'

'

'

'

700,000

'

Cash consideration and shares issued placed in escrow

'

'

'

'

'

'

'

'

'

'

'

'

'

1,800,000

'

'

'

'

'

'

'

'

Reasons for business acquisition, size of target client by number of employees

'

'

'

'

'

'

'

'

'

'

'

'

'

400

'

'

'

'

'

'

'

'

Identified intangible assets amortization period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'4 years

'2 years 6 months

'2 years

'

'

'

Identified intangible assets combined weighted average useful life

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years 9 months 18 days

'

'

'

'

'

'

'

Acquisition related costs

'

'

'

'

'

'

'

'

'

'

'

0

700,000

'

'

'

'

'

'

'

'

700,000

Net revenue attributable to Sonar

54,856,000

48,270,000

44,346,000

37,657,000

36,426,000

30,768,000

26,718,000

24,002,000

185,129,000

117,914,000

73,022,000

'

'

'

'

'

'

'

'

'

'

'

Net loss attributable to Sonar

$10,755,000

$11,054,000

$8,683,000

$9,934,000

$7,417,000

$7,627,000

$8,234,000

$8,112,000

$40,426,000

$31,390,000

$63,900,000

'

'

'

'

'

'

'

'

'

'

'

Award ratable vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2 years

'

Business_Acquisition_Allocatio

Business Acquisition - Allocation of Total Purchase Consideration (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Apr. 05, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Business Acquisition [Line Items]	'	'	'	'
Goodwill	$8,193	$8,193	'	$0
Other assets, cash	'	'	76	'
Sonar Limited	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Acquired intangible assets	'	'	7,130	'
Goodwill	'	'	8,193	'
Other assets (including cash of $76)	'	'	815	'
Current liabilities	'	'	-506	'
Deferred revenue	'	'	427	'
Borrowings	'	'	-557	'
Net deferred tax liabilities	'	'	1,809	'
Net Assets Acquired	'	'	12,839	'
Sonar Limited | Developed technology	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Acquired intangible assets	'	'	3,800	'
Sonar Limited | Customer relationships	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Acquired intangible assets	'	'	2,400	'
Sonar Limited | Non-compete agreements	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Acquired intangible assets	'	'	610	'
Sonar Limited | Domains/trademarks/tradenames	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Acquired intangible assets	'	'	$320	'

Business_Acquisition_Unaudited

Business Acquisition - Unaudited Pro forma Financial Information (Details) (Sonar Limited, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Sonar Limited	'	'	'
Business Acquisition [Line Items]	'	'	'
Revenue	$185,129	$118,917	$76,449
Net loss	($40,426)	($31,072)	($65,342)

Net_Loss_Per_Share_Attributabl2

Net Loss Per Share Attributable to Common Stockholders - Basic and Diluted Loss Per Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net loss attributable to common stockholders	'	'	'	'	'	'	'	'	($40,426)	($31,390)	($69,108)
Weighted-average shares of common stock outstanding, excluding shares issued upon early exercise of unvested options and unvested restricted stock	52,185	51,544	51,153	50,798	50,486	50,163	49,763	49,384	51,427	49,929	39,824
Net loss per share attributable to common stockholders—basic and diluted	($0.21)	($0.21)	($0.17)	($0.20)	($0.15)	($0.15)	($0.17)	($0.16)	($0.79)	($0.63)	($1.74)

Net_Loss_Per_Share_Attributabl3

Net Loss Per Share Attributable to Common Stockholders - Anti-dilutive Shares Excluded From Calculation of Diluted Net Loss Per Share (Details)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Shares excluded from net loss per share attributable to common stockholders	17,106	7,388	6,005
Options to purchase common stock and restricted stock units	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Shares excluded from net loss per share attributable to common stockholders	7,730	7,331	5,845
Convertible Debt	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Shares excluded from net loss per share attributable to common stockholders	4,682	0	0
Warrants | Common Stock	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Shares excluded from net loss per share attributable to common stockholders	4,682	0	130
Shares issued for purchase consideration held in escrow	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Shares excluded from net loss per share attributable to common stockholders	0	16	0
Common Stock Repurchase Program	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Shares excluded from net loss per share attributable to common stockholders	0	10	30
Other restricted common stock	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Shares excluded from net loss per share attributable to common stockholders	12	31	0

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets - Finite-lived Intangibles (Details) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Apr. 30, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jan. 31, 2012

Cost of revenues

Cost of revenues

Cost of revenues

Finite-lived intangible assets

Finite-lived intangible assets

Finite-lived intangible assets

Sonar Limited

Developed technology

Developed technology

Customer relationships

Customer relationships

Domains/trademarks/tradenames

Domains/trademarks/tradenames

Software license rights

Software license rights

Non-compete agreements

Non-compete agreements

Intellectual property rights

Finite-Lived Intangible Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gross Carrying Amount

$8,784,000

$8,784,000

'

'

'

'

'

'

'

$3,800,000

$3,800,000

$2,400,000

$2,400,000

$320,000

$320,000

$1,654,000

$1,654,000

$610,000

$610,000

'

Accumulated Amortization

-4,152,000

-1,897,000

'

'

'

'

'

'

'

-1,649,000

-700,000

-1,042,000

-441,000

-278,000

-118,000

-759,000

-459,000

-424,000

-179,000

'

Net Carrying Amount

4,632,000

6,887,000

'

'

'

'

'

'

'

2,151,000

3,100,000

1,358,000

1,959,000

42,000

202,000

895,000

1,195,000

186,000

431,000

'

Intangible assets acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

800,000

Additional finite lived intangible assets

'

'

'

'

'

'

'

'

7,100,000

'

'

'

'

'

'

'

'

'

'

'

Amortization expense

'

'

$1,300,000

$1,000,000

$100,000

$2,300,000

$1,700,000

$100,000

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets - Estimated Amortization Expense for Finite-Lived Intangible Assets (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Expected Amortization Expense [Line Items]	'	'
2014	$2,078	'
2015	1,840	'
2016	555	'
2017	146	'
2018	13	'
Net Carrying Amount	4,632	6,887
Cost of revenue	'	'
Expected Amortization Expense [Line Items]	'	'
2014	1,200	'
2015	1,200	'
2016	400	'
2017	100	'
2018	$13	'

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets - Goodwill (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Changes in Carrying Amount of Goodwill	'	'
Goodwill as of December 31, 2012	$8,193	$0
Adjustments	0	8,193
Goodwill as of December 31, 2013	$8,193	$8,193

Other_Balance_Sheet_Amounts_Pr

Other Balance Sheet Amounts - Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property and Equipment [Details]	'	'	'
Property and equipment, gross	$23,177,000	$13,513,000	'
Less: accumulated depreciation and amortization	-8,741,000	-5,566,000	'
Total property and equipment, net	14,436,000	7,947,000	'
Depreciation expense	3,200,000	2,500,000	1,800,000
Computer equipment and software	'	'	'
Property and Equipment [Details]	'	'	'
Property and equipment, gross	15,768,000	9,976,000	'
Capital leased assets, gross	2,800,000	4,600,000	'
Capital leased assets, accumulated depreciation	2,000,000	2,800,000	'
Capital leased assets, depreciation expense	900,000	1,100,000	900,000
Computer equipment and software | Minimum	'	'	'
Property and Equipment [Details]	'	'	'
Property, plant and equipment, useful life	'2 years	'	'
Computer equipment and software | Maximum	'	'	'
Property and Equipment [Details]	'	'	'
Property, plant and equipment, useful life	'5 years	'	'
Furniture and fixtures	'	'	'
Property and Equipment [Details]	'	'	'
Property and equipment, gross	2,265,000	869,000	'
Property, plant and equipment, useful life	'7 years	'	'
Leasehold improvements	'	'	'
Property and Equipment [Details]	'	'	'
Property and equipment, gross	4,190,000	1,520,000	'
Leasehold improvements | Minimum	'	'	'
Property and Equipment [Details]	'	'	'
Property, plant and equipment, useful life	'2 years	'	'
Leasehold improvements | Maximum	'	'	'
Property and Equipment [Details]	'	'	'
Property, plant and equipment, useful life	'6 years	'	'
Renovation in progress	'	'	'
Property and Equipment [Details]	'	'	'
Property and equipment, gross	$954,000	$1,148,000	'

Other_Balance_Sheet_Amounts_Ac

Other Balance Sheet Amounts - Accrued Expenses (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accrued Expenses	'	'
Accrued bonuses	$6,860	$5,229
Accrued Sales Commission	7,246	3,826
Other accrued expenses	8,182	5,931
Total accrued expenses	$22,288	$14,986

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	$265,625	'
Recurring basis | Fair Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	65,700	51,521
Assets, Fair Value Disclosure	265,625	51,521
Recurring basis | Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	65,700	51,521
Assets, Fair Value Disclosure	65,700	51,521
Recurring basis | Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	0	0
Assets, Fair Value Disclosure	199,925	0
Recurring basis | Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	0	0
Assets, Fair Value Disclosure	0	0
Corporate Bond Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	78,609	'
Corporate Bond Securities | Recurring basis | Fair Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	78,609	0
Corporate Bond Securities | Recurring basis | Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Corporate Bond Securities | Recurring basis | Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	78,609	0
Corporate Bond Securities | Recurring basis | Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Agency Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	121,316	'
Agency Securities | Recurring basis | Fair Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	121,316	0
Agency Securities | Recurring basis | Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Agency Securities | Recurring basis | Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	121,316	0
Agency Securities | Recurring basis | Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	$0	$0

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Fair Value of Preferred Stock Warrant Liabilities (Details) (Warrants, USD $)	12 Months Ended	1 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2011	Mar. 31, 2011	Mar. 31, 2011	Mar. 31, 2011
	Preferred stock	Series C Preferred Stock	Series D Preferred Stock	Series E preferred stock
Changes in the fair value of preferred stock warrant liability [Roll Forward]	'	'	'	'
Fair value at beginning of period	$39,756	'	'	'
Changes in fair value of preferred stock warrant liabilities recorded in the statement of operations	42,559	'	'	'
Exercise of preferred stock warrants	-82,315	'	'	'
Fair value at end of period	0	'	'	'
Weighted-Average Assumptions Used to Determine Fair Value of Preferred Stock Warrants	'	'	'	'
Risk-free interest rate	'	0.10%	0.10%	0.10%
Expected term	'	'0 years	'0 years	'0 years
Estimated dividend yield	'	0.00%	0.00%	0.00%
Weighted-average estimated volatility	'	43.10%	43.10%	43.10%
Fair value	'	$3,905	$56,445	$21,965

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments - Additional Information (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]	'
Convertible Debt, Fair Value Disclosures	$305.40

Debt_and_Other_Financing_Arran2

Debt and Other Financing Arrangements - Convertible Debt (Details) (USD $)	Dec. 31, 2013	Jun. 17, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Principal amount	$911	'
Convertible Debt	'	'
Debt Instrument [Line Items]	'	'
Principal amount	253,000	'
Unamortized debt discount	-35,035	'
Net carrying value	$217,965	$214,300

Debt_and_Other_Financing_Arran3

Debt and Other Financing Arrangements - Schedule of Debt Cost and Interest Expense (Details) (Convertible Debt, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Convertible Debt	'
Debt Instrument [Line Items]	'
Contractual interest expense at 1.5% per annum	$2,045
Amortization of debt issuance costs	591
Accretion of debt discount	3,681
Total	$6,317

Debt_and_Other_Financing_Arran4

Debt and Other Financing Arrangements - Maturities of Outstanding Borrowings (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Maturities of Outstanding Borrowings	'
2014	$519
2015	382
Long-term Debt, Gross, Maturities, Repayments of Principal in Year Three	10
Total long-term debt	$911

Debt_and_Other_Financing_Arran5

Debt and Other Financing Arrangements Debt - Additional Information (Details) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

1 Months Ended

Jun. 17, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Jun. 17, 2013

Dec. 31, 2013

Jun. 17, 2013

Jun. 17, 2013

Jun. 30, 2013

Nov. 30, 2012

Other Debt Arrangements

Other Debt Arrangements

Convertible Debt

Convertible Debt

Prior to April 1, 2018

Prior to April 1, 2018

Silicon Valley Bank

Silicon Valley Bank

Maximum

Minimum

Amended Line of Credit

Amended Line of Credit

Convertible Debt

Convertible Debt

trading_day

trading_day

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Short-term Debt, Weighted Average Interest Rate

'

7.00%

5.20%

'

'

'

'

'

'

'

'

'

Proceeds from Issuance of Long-term Debt

'

'

'

'

'

'

$246,000,000

'

'

'

'

'

Debt Instrument, Face Amount

'

'

'

'

'

'

253,000,000

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

'

'

1.50%

'

'

'

'

'

Debt Instrument, Convertible, Conversion Ratio

'

'

'

'

'

'

18.5046

'

'

'

'

'

Debt Instrument, Convertible, Conversion Price

$54.04

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Threshold Trading Days

'

'

'

'

'

'

'

'

20

5

'

'

Debt Instrument, Convertible, Threshold Consecutive Trading Days

'

'

'

'

'

'

'

'

'30 days

'5 days

'

'

Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger

'

'

'

'

'

'

'

'

130.00%

98.00%

'

'

Convertible Debt

'

'

'

'

'

'

214,300,000

217,965,000

'

'

'

'

Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt

'

11,282,000

'

'

'

'

38,700,000

'

'

'

'

'

Debt Issuance Cost

'

'

'

'

'

'

7,300,000

'

'

'

'

'

Unamortized Debt Issuance Expense

'

'

'

'

'

'

6,200,000

'

'

'

'

'

Debt Instrument, Convertible, Issuance Cost Allocated to Equity Components

'

'

'

'

'

'

1,100,000

'

'

'

'

'

Payments for Derivative Instrument, Financing Activities

49,500,000

49,537,000

0

0

'

'

'

'

'

'

'

'

Derivative, Nonmonetary Notional Amount, Number of Shares

4,700,000

'

'

'

'

'

'

'

'

'

'

'

Proceeds from the issuance of warrants

'

23,225,000

0

0

'

'

'

'

'

'

'

'

Number of shares purchasable upon warrant exercise

'

4,700,000

'

'

'

'

'

'

'

'

'

'

Warrants exercise price (in usd per share)

'

80.06

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Maximum Borrowing Capacity

'

'

'

'

'

'

'

'

'

'

'

5,000,000

Repayments of Lines of Credit

'

'

'

'

'

'

'

'

'

'

3,000,000

'

Debt Instrument, Amount Outstanding

'

'

'

'

900,000

1,400,000

'

'

'

'

'

'

Debt Instrument, Fair Value Disclosure

'

$900,000

$1,400,000

'

'

'

'

'

'

'

'

'

Capitalization_Details

Capitalization (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2011
			Common Stock
Class of Stock [Line Items]	'	'	'
Common stock, shares authorized	1,000,000,000	1,000,000,000	'
Common stock, par value (in usd per share)	$0.00	$0.00	'
Preferred stock, shares authorized	50,000,000	'	'
Preferred stock, par value (in usd per share)	$0.00	'	'
Automatic conversion of then-outstanding preferred stock into common stock (in shares)	'	'	28,809,031
Number of shares of common stock each preferred stock was converted into	'	'	1

Warrants_Common_Stock_Details

Warrants - Common Stock (Details) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

11 Months Ended

1 Months Ended

In Thousands, except Share data, unless otherwise specified

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2011

6-May-09

6-May-09

6-May-09

Nov. 24, 2010

Mar. 22, 2011

Jun. 30, 2011

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

ADP ten-year warrants

ADP ten-year warrants

ADP ten-year warrants

ADP ten-year warrants

ADP ten-year warrants

ADP ten-year warrants

ADP ten-year warrants

Issued on May 6, 2009

Issued on May 6, 2009

Issued on May 6, 2009

Issued on November 24, 2010

Unissued warrants in dispute

Issued in June 2011

Minimum

Maximum

Class of Warrant or Right [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Warrants outstanding (in shares)

'

'

'

'

0

'

'

'

'

'

'

'

Issuance of common stock for the exercise of warrants to purchase common stock (in shares)

'

'

130,000

898,447

'

133,000

'

'

'

'

'

'

Weighted-average exercise price of warrants exercised (in usd per share)

'

'

$1.60

$0.95

'

'

'

'

'

'

'

'

Warrants exercisable period

'

'

'

'

'

'

'10 years

'

'

'

'

'

Number of shares purchasable upon warrant exercise

'

4,700,000

'

'

'

'

'

0

886,096

360,000

443,048

133,000

Warrants exercise price (in usd per share)

'

80.06

'

'

'

'

0.53

'

'

0.01

0.53

0.53

Value of warrants issued

$2,500

'

'

'

'

'

'

'

'

$2,900

'

$2,500

Stock_Option_Plans_Plans_Infor

Stock Option Plans - Plans Information (Details)

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 01, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Sep. 20, 2010

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Restricted stock awards

Restricted stock units

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

1999 and 2009 Plans

2010 Plan

2010 Plan

2010 Plan

2010 Plan

2010 Plan

2010 Plan

2010 Plan

Stock options

Stock options

Stock options

Stock options

Stock options

Stock options

Stock options

Incentive stock options

Incentive stock options

Non-statutory stock options

Maximum

Minimum

Incentive stock options

Incentive stock options

Incentive stock options

Restricted stock units

Maximum

Board member

Grantee other than individual owning more than 10% of outstanding stock

Grantee other than individual owning more than 10% of outstanding stock

Grantee other than individual owning more than 10% of outstanding stock

Individual owning more than 10% of outstanding stock

Minimum

Individual owning more than 10% of outstanding stock

Minimum

Maximum

Individual owning more than 10% of outstanding stock

Individual owning more than 10% of outstanding stock

Cliff vesting on first anniversary of grant

Cliff vesting on first anniversary of grant

Ratable vesting after first anniversary of grant

Minimum

Maximum

Minimum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum vesting rate, percentage per year over 5 years

'

'

'

'

'

20.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum vesting rate, period

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Award expiration period

'

'

'

'

'

'

'10 years

'

'10 years

'

'

'

'

'5 years

'

'

'

'

'10 years

'5 years

'

'

Award cliff vesting percentage

'

'

'

'

'

'

'

33.33%

'

25.00%

'

'

'

'

'

'

'

'

'

'

'

'

Award ratable vesting period

'

'

'

'

'

'

'

'

'

'

'36 months

'

'

'

'

'

'

'

'

'

'

'

Exercise price as percentage of fair market value per share

'

'

'

'

'

'

'

'

'

'

'

110.00%

100.00%

'

85.00%

'

'

'

'

'

110.00%

'

Stock Based Compensation Plan, Individual Ownership Threshold

10.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock options granted (in shares)

2,394,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares issuable under plan

'

'

'

0

0

'

'

'

'

'

'

'

'

'

'

2,015,533

'

'

'

'

'

'

Number of shares authorized under plan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,680,480

'

'

'

'

Number of shares to be added from 1999 and 2009 Plans

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,614,369

'

'

'

'

'

Additional issuable shares authorization, annual increase, maximum number of shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,500,000

'

'

'

'

'

'

Additional issuable shares authorization, annual increase, percentage of outstanding stock, maximum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4.50%

'

'

'

'

'

'

Awards granted (in shares/units)

'

7,500

173,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

172,465

Awards vested (in shares/units)

'

'

214,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock_Option_Plans_Summary_of_

Stock Option Plans - Summary of Stock Option Activity (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Stock Options Outstanding, Shares	'	'
Shares Outstanding, December 31, 2012	6,610	'
Stock options granted (in shares)	2,394	'
Shares Exercised	-1,566	'
Shares Forfeited	-311	'
Shares Outstanding, December 31, 2013	7,127	6,610
Stock Options Outstanding, Weighted Average Exercise Price	'	'
Weighted Average Exercise Price, Outstanding, December 31, 2012 (in usd per share)	$12.49	'
Weighted Average Exercise Price, Granted (in usd per share)	$43.32	'
Weighted Average Exercise Price, Exercised (in usd per share)	$8.58	'
Weighted Average Exercise Price, Forfeited (in usd per share)	$27	'
Weighted Average Exercise Price, Outstanding, December 31, 2013 (in usd per share)	$23.07	$12.49
Stock Options, Additional Disclosures	'	'
Weighted Average Remaining Contractual Term, Outstanding	'8 years 1 month 6 days	'8 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding	$215,549	$112,899
Shares Exercisable at December 31, 2013	2,890	'
Weighted Average Exercise Price, Exercisable at December 31, 2013 (in usd per share)	$10.46	'
Weighted Average Remaining Contractual Term, Exercisable at December 31, 2013	'7 years	'
Aggregate Intrinsic Value, Exercisable at December 31, 2013	123,833	'
Stock Options Vested and Expected to Vest	'	'
Shares Vested and Expected to Vest at December 31, 2013	7,022	'
Weighted Average Exercise Price, Vested and Expected to Vest at December 31, 2013 (in usd per share)	$22.91	'
Weighted Average Remaining Contractual Term, Vested and Expected to Vest at December 31, 2013	'8 years 1 month 6 days	'
Aggregate Intrinsic Value, Vested and Expected to Vest at December 31, 2013	$213,492	'

Stock_Option_Plans_Options_Out

Stock Option Plans - Options Outstanding and Exercisable (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Options Outstanding, Number of Options	7,127
Options Outstanding, Weighted Average Remaining Contractual Life	'8 years 0 months 26 days
Options Exercisable, Number of Options	2,890
Options Exercisable, Weighted Average Remaining Contractual Life	'7 years 0 months 12 days
$0.34 to $1.65	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	0.34
Range of Exercise Prices, Upper (in usd per share)	1.65
Options Outstanding, Number of Options	841
Options Outstanding, Weighted Average Remaining Contractual Life	'5 years 6 months 23 days
Options Exercisable, Number of Options	800
Options Exercisable, Weighted Average Remaining Contractual Life	'5 years 6 months 9 days
$5.93 to $8.88	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	5.93
Range of Exercise Prices, Upper (in usd per share)	8.88
Options Outstanding, Number of Options	1,219
Options Outstanding, Weighted Average Remaining Contractual Life	'6 years 10 months 15 days
Options Exercisable, Number of Options	866
Options Exercisable, Weighted Average Remaining Contractual Life	'6 years 10 months 16 days
$12.54 to $15.41	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	12.54
Range of Exercise Prices, Upper (in usd per share)	15.41
Options Outstanding, Number of Options	596
Options Outstanding, Weighted Average Remaining Contractual Life	'7 years 8 months 17 days
Options Exercisable, Number of Options	289
Options Exercisable, Weighted Average Remaining Contractual Life	'7 years 8 months 13 days
$16.24 to $18.82	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	16.24
Range of Exercise Prices, Upper (in usd per share)	18.82
Options Outstanding, Number of Options	732
Options Outstanding, Weighted Average Remaining Contractual Life	'7 years 11 months 28 days
Options Exercisable, Number of Options	458
Options Exercisable, Weighted Average Remaining Contractual Life	'8 years 0 months 11 days
$20.85 to $23.94	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	20.85
Range of Exercise Prices, Upper (in usd per share)	23.94
Options Outstanding, Number of Options	1,095
Options Outstanding, Weighted Average Remaining Contractual Life	'8 years 4 months 16 days
Options Exercisable, Number of Options	366
Options Exercisable, Weighted Average Remaining Contractual Life	'8 years 4 months 8 days
$27.75 to $31.44	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	27.75
Range of Exercise Prices, Upper (in usd per share)	31.44
Options Outstanding, Number of Options	394
Options Outstanding, Weighted Average Remaining Contractual Life	'8 years 10 months 8 days
Options Exercisable, Number of Options	104
Options Exercisable, Weighted Average Remaining Contractual Life	'8 years 10 months 5 days
$33.34 to $36.15	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	33,340
Range of Exercise Prices, Upper (in usd per share)	36,150
Options Outstanding, Number of Options	609
Options Outstanding, Weighted Average Remaining Contractual Life	'9 years 2 months 3 days
Options Exercisable, Number of Options	4
Options Exercisable, Weighted Average Remaining Contractual Life	'9 years 1 month 27 days
$40.03 to $45.76	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	40,030
Range of Exercise Prices, Upper (in usd per share)	45,760
Options Outstanding, Number of Options	895
Options Outstanding, Weighted Average Remaining Contractual Life	'9 years 6 months 8 days
Options Exercisable, Number of Options	2
Options Exercisable, Weighted Average Remaining Contractual Life	'9 years 10 months 2 days
$50.42 to $52.72	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower (in usd per share)	50,420
Range of Exercise Prices, Upper (in usd per share)	52,720
Options Outstanding, Number of Options	746
Options Outstanding, Weighted Average Remaining Contractual Life	'9 years 8 months 21 days
Options Exercisable, Number of Options	1
Options Exercisable, Weighted Average Remaining Contractual Life	'9 years 10 months 30 days

Stock_Option_Plans_Stock_Optio

Stock Option Plans - Stock Option Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Compensation expense recognized	$20,840,000	$12,207,000	$4,502,000
Stock options	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Total intrinsic value of options exercised	57,700,000	23,900,000	19,500,000
Compensation expense recognized	17,200,000	10,300,000	3,800,000
Unrecognized compensation expense related to options	59,600,000	'	'
Unrecognized compensation expense, weighted-average period of recognition	'2 years 8 months 1 day	'	'
Aggregate grant date fair value of stock options granted	$51,500,000	$28,400,000	$11,900,000

Stock_Option_Plans_Restricted_

Stock Option Plans - Restricted Stock Awards and Restricted Stock Units (Details) (USD $)	12 Months Ended			0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 01, 2011	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
				Restricted stock awards	Restricted stock awards	Restricted stock units	Restricted stock units	Restricted stock units	Restricted Stock Shares
					Sonar Limited				Restricted stock awards
									Sonar Limited
Nonvested Shares Subject to Performance Based Awards, Number of Shares	'	'	'	'	'	'	'	'	'
Number of Shares, Outstanding at December 31, 2012	'	'	'	'	'	425,000	'	'	'
Number of Shares, Granted	'	'	'	7,500	'	173,000	'	'	31,164
Number of Shares, Forfeited	'	'	'	'	'	-2,000	'	'	'
Number of Shares, Vested	'	'	'	'	'	-214,000	'	'	'
Number of Shares, Outstanding at December 31, 2013	'	'	'	'	'	382,000	425,000	'	'
Nonvested Shares Subject to Performance Based Awards, Weighted Average Grant Date Fair Value	'	'	'	'	'	'	'	'	'
Weighted Average Grant Date Fair Value, Outstanding at December 31, 2012 (in usd per share)	'	'	'	'	'	$14.37	'	'	'
Weighted Average Grant Date Fair Value, Granted (in usd per share)	'	'	'	'	'	$42.90	'	'	'
Weighted Average Grant Date Fair Value, Forfeited (in usd per share)	'	'	'	'	'	$40.03	'	'	'
Weighted Average Grant Date Fair Value, Vested (in usd per share)	'	'	'	'	'	$13.15	'	'	'
Weighted Average Grant Date Fair Value, Outstanding at December 31, 2013 (in usd per share)	'	'	'	'	'	$27.81	$14.37	'	'
Additional Information	'	'	'	'	'	'	'	'	'
Aggregated grant date fair value	'	'	'	$100,000	'	'	'	'	$700,000
Award vesting period	'	'	'	'	'2 years	'	'	'	'
Vested awards	'	'	'	'	18,698	'	'	'	'
Compensation expense recognized	20,840,000	12,207,000	4,502,000	'	'	3,400,000	1,700,000	600,000	'
Unrecognized compensation expense related to nonvested restricted stock units	'	'	'	'	'	$8,700,000	'	'	'
Unrecognized compensation expense, weighted-average period of recognition	'	'	'	'	'	'2 years 3 months	'	'	'

Stock_Option_Plans_Performance

Stock Option Plans - Performance Awards (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted Average Exercise Price, Outstanding (in usd per share)	$23.07	$12.49	'
Share-based compensation expense	$20,840,000	$12,207,000	$4,502,000
Performance awards	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Award vesting period	'4 years	'	'
Award expiration period	'10 years	'	'
Share-based compensation expense	300,000	400,000	'
Unrecognized compensation expense	$400,000	'	'
Unrecognized compensation expense, weighted-average period of recognition	'2 years	'	'
Performance based stock options	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted Average Exercise Price, Outstanding (in usd per share)	$27.75	'	'
Weighted Average Exercise Price, Expected to Vest	53,714	'	'
Performance based stock options | Minimum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted Average Exercise Price, Expected to Vest	179,047	'	'
Performance based restricted stock units	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted Average Exercise Price, Expected to Vest	12,892	'	'
Performance based restricted stock units | Maximum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted Average Exercise Price, Expected to Vest	43,066	'	'

Stock_Option_Plans_StockBased_

Stock Option Plans - Stock-Based Compensation Expense (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Share-based compensation expense	$20,840	$12,207	$4,502
Cost of revenue	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Share-based compensation expense	2,207	1,660	581
Sales and marketing	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Share-based compensation expense	9,866	3,982	1,121
Research and development	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Share-based compensation expense	2,052	949	755
General and administrative	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Share-based compensation expense	$6,715	$5,616	$2,045

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Components of Loss before Provision for Income Taxes	'	'	'	'	'	'	'	'	'	'	'
United States	'	'	'	'	'	'	'	'	($36,821,000)	($20,173,000)	($60,300,000)
Foreign	'	'	'	'	'	'	'	'	-3,733,000	-12,006,000	-3,419,000
Loss before income tax benefit (provision)	-10,852,000	-10,950,000	-8,819,000	-9,933,000	-7,656,000	-7,925,000	-8,568,000	-8,030,000	-40,554,000	-32,179,000	-63,719,000
Current income tax provision:	'	'	'	'	'	'	'	'	'	'	'
Federal	'	'	'	'	'	'	'	'	0	0	0
State	'	'	'	'	'	'	'	'	117,000	0	0
Foreign	'	'	'	'	'	'	'	'	620,000	176,000	181,000
Total current income tax provision	'	'	'	'	'	'	'	'	737,000	176,000	181,000
Deferred income tax benefit:	'	'	'	'	'	'	'	'	'	'	'
Federal	'	'	'	'	'	'	'	'	0	0	0
State	'	'	'	'	'	'	'	'	0	0	0
Foreign	'	'	'	'	'	'	'	'	-865,000	-965,000	0
Total deferred income tax benefit	'	'	'	'	'	'	'	'	-865,000	-965,000	0
Total income tax (benefit) provision	-97,000	104,000	-136,000	1,000	-239,000	-298,000	-334,000	82,000	-128,000	-789,000	181,000
Federal statutory tax rate	'	'	'	'	'	'	'	'	34.00%	34.00%	34.00%
Effective Income Tax Rate Reconciliation	'	'	'	'	'	'	'	'	'	'	'
U.S. Federal tax benefit at statutory rates	'	'	'	'	'	'	'	'	-13,784,000	-10,941,000	-21,688,000
State income taxes, net of federal tax benefit	'	'	'	'	'	'	'	'	-415,000	-60,000	-916,000
Foreign rate differential	'	'	'	'	'	'	'	'	1,354,000	1,008,000	219,000
Preferred stock warrant charges	'	'	'	'	'	'	'	'	0	0	14,470,000
Stock based compensation	'	'	'	'	'	'	'	'	2,039,000	1,360,000	474,000
Other permanent differences	'	'	'	'	'	'	'	'	410,000	654,000	188,000
Other	'	'	'	'	'	'	'	'	76,000	-194,000	206,000
Valuation allowance	'	'	'	'	'	'	'	'	10,192,000	7,384,000	7,228,000
Total income tax (benefit) provision	-97,000	104,000	-136,000	1,000	-239,000	-298,000	-334,000	82,000	-128,000	-789,000	181,000
Deferred Tax Assets	'	'	'	'	'	'	'	'	'	'	'
Accrued expenses	2,029,000	'	'	'	1,306,000	'	'	'	2,029,000	1,306,000	'
Long-lived intangible assets — basis difference	7,846,000	'	'	'	5,155,000	'	'	'	7,846,000	5,155,000	'
Net operating loss carryforwards	33,823,000	'	'	'	24,392,000	'	'	'	33,823,000	24,392,000	'
Stock-based compensation	4,818,000	'	'	'	2,671,000	'	'	'	4,818,000	2,671,000	'
Deferred revenue	1,905,000	'	'	'	2,375,000	'	'	'	1,905,000	2,375,000	'
Deferred Tax Assets Financing Arrangements	16,705,000	'	'	'	0	'	'	'	16,705,000	0	'
Other	452,000	'	'	'	274,000	'	'	'	452,000	274,000	'
Total deferred tax assets	67,578,000	'	'	'	36,173,000	'	'	'	67,578,000	36,173,000	'
Valuation allowance	-48,558,000	'	'	'	-34,081,000	'	'	'	-48,558,000	-34,081,000	'
Deferred tax assets, net of valuation allowance	19,020,000	'	'	'	2,092,000	'	'	'	19,020,000	2,092,000	'
Deferred Tax Liabilities	'	'	'	'	'	'	'	'	'	'	'
Prepaid expenses and deferred commissions	-3,613,000	'	'	'	-2,029,000	'	'	'	-3,613,000	-2,029,000	'
Long-lived fixed assets — basis difference	-2,136,000	'	'	'	-805,000	'	'	'	-2,136,000	-805,000	'
Deferred Tax Liabilities, Financing Arrangements	-13,028,000	'	'	'	0	'	'	'	-13,028,000	0	'
Other	-120,000	'	'	'	0	'	'	'	-120,000	0	'
Total deferred tax liabilities	-18,897,000	'	'	'	-2,834,000	'	'	'	-18,897,000	-2,834,000	'
Net deferred tax assets (liabilities)	123,000	'	'	'	-742,000	'	'	'	123,000	-742,000	'
Federal, state and foreign net operating losses	145,800,000	'	'	'	152,800,000	'	'	'	145,800,000	152,800,000	18,000,000
Net increase to valuation allowance primarily due to additional net operating losses	'	'	'	'	'	'	'	'	14,500,000	7,400,000	7,200,000
Share-based compensation tax benefit not recognized in deferred tax assets	25,800,000	'	'	'	'	'	'	'	25,800,000	'	'
Undistributed foreign earnings	900,000	'	'	'	500,000	'	'	'	900,000	500,000	'
Potential tax impact if undistributed foreign earnings were distributed	125,000	'	'	'	76,000	'	'	'	125,000	76,000	'
Reconciliation of Unrecognized Tax Benefits	'	'	'	'	'	'	'	'	'	'	'
Balance at January 1	'	'	'	276,000	'	'	'	276,000	276,000	276,000	276,000
Additions for tax positions related to the current year	'	'	'	'	'	'	'	'	0	0	0
Balance at December 31	276,000	'	'	'	276,000	'	'	'	276,000	276,000	276,000
Reduction in tax expense if unrecognized tax benefits are recognized	$300,000	'	'	'	'	'	'	'	$300,000	'	'

Geographic_Information_Details

Geographic Information (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	$54,856	$48,270	$44,346	$37,657	$36,426	$30,768	$26,718	$24,002	$185,129	$117,914	$73,022
Reduction of revenue relating to common stock warrants	'	'	'	'	'	'	'	'	0	0	2,500
Property and equipment, net	14,436	'	'	'	7,947	'	'	'	14,436	7,947	'
United States	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	128,983	81,837	50,874
Reduction of revenue relating to common stock warrants	'	'	'	'	'	'	'	'	'	'	2,500
Property and equipment, net	10,455	'	'	'	7,529	'	'	'	10,455	7,529	'
United Kingdom	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	19,448	12,930	8,612
Property and equipment, net	3,185	'	'	'	343	'	'	'	3,185	343	'
All Other Countries	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	36,698	23,147	13,536
Property and equipment, net	$796	'	'	'	$75	'	'	'	$796	$75	'

401k_Saving_Plan_Details

401(k) Saving Plan (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]	'	'
401(k) employer matching percentage	50.00%	'
Maximum 401(k) annual contributions by employer per employee	$2,400	'
401(k) vesting period	'4 years	'
401(k) matching contribution expenses	$800,000	$300,000

Commitments_and_Contingencies_1

Commitments and Contingencies - Leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Loss Contingencies [Line Items]	'	'	'
Rent expense under operating leases	$4,100,000	$3,200,000	$1,900,000
Future Minimum Lease Payments under Non-cancelable Capital Leases	'	'	'
2014	943,000	'	'
2015	217,000	'	'
2016	4,000	'	'
2017	0	'	'
2018	0	'	'
Thereafter	0	'	'
Total minimum lease payments	1,164,000	'	'
Less: Amounts representing interest	-41,000	'	'
Present value of capital lease obligations	1,123,000	'	'
Less: Current portion	-905,000	-1,643,000	'
Long-term portion of capital lease obligations	218,000	1,227,000	'
Building lease and other commitments	'	'	'
Future Minimum Lease Payments under Non-cancelable Operating Leases	'	'	'
2014	4,938,000	'	'
2015	5,042,000	'	'
2016	5,365,000	'	'
2017	5,511,000	'	'
2018	5,512,000	'	'
Thereafter	410,000	'	'
Total minimum lease payments	$26,778,000	'	'

Commitments_and_Contingencies_2

Commitments and Contingencies - Letters of Credit (Details) (Standby letters of credit, Building lease and other commitments, USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Standby letters of credit | Building lease and other commitments	'
Loss Contingencies [Line Items]	'
Letter of credit outstanding	$1.50

Commitments_and_Contingencies_3

Commitments and Contingencies - Additional Information (Detail) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Long-term Purchase Commitment [Line Items]	'
Contractual commitment due in 2014	$15.30
Contractual commitment due in 2015	15.2
Contractual commitment due in 2016	3.8
Contractual commitment due in 2017	3.8
Contractual commitment due in 2018	3.8
Contractual commitment due after 2018	3.5
Litigation	'
Estimated probable loss, amount accrued	2.6
Cloud subscription agreement	'
Long-term Purchase Commitment [Line Items]	'
Contractual commitment due in 2014	0.8
Contractual commitment due in 2015	$1

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Related Party Transaction [Line Items]	'	'	'
Value Of Resources Donated To Related Parties	$1.30	'	'
Director	'	'	'
Related Party Transaction [Line Items]	'	'	'
Related Party Transaction, Expenses from Transactions with Related Party	$0.50	$0.30	$0.10

Subsequent_Events_Detail

Subsequent Events (Detail) (USD $)	12 Months Ended	1 Months Ended	2 Months Ended	1 Months Ended	2 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Jan. 31, 2014	Feb. 26, 2014	Jan. 31, 2014	Feb. 26, 2014
		Subsequent event	Subsequent event	Subsequent event	Subsequent event
		Employee stock purchase plan	Stock options	Stock options	Restricted Stock Units (RSUs) [Member]
				2010 Plan
Subsequent Event [Line Items]	'	'	'	'	'
Contractual Obligation, Due in Second Year	$15.20	'	'	'	'
Increase in shares authorized under plan	'	524,699	'	2,361,145	'
Stock options granted (in shares)	2,394,000	'	284,670	'	10,500
Stock options granted, weighted average exercise price (in usd per share)	$43.32	'	$55.51	'	'
Award vesting period	'	'	'4 years	'	'4 years
Contractual Obligation, Due in Next Twelve Months	15.3	'	'	'	'
Contractual Obligation, Due in Third Year	$3.80	'	'	'	'

Selected_Quarterly_Data_Unaudi2

Selected Quarterly Data (Unaudited) - Quarterly Consolidated Statements of Operations (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Unaudited Quarterly Consolidated Statements of Operations	'	'	'	'	'	'	'	'	'	'	'
Revenue	$54,856	$48,270	$44,346	$37,657	$36,426	$30,768	$26,718	$24,002	$185,129	$117,914	$73,022
Cost of revenue	15,488	13,644	13,164	11,252	10,722	9,135	7,890	6,844	53,548	34,591	21,285
Gross profit	39,368	34,626	31,182	26,405	25,704	21,633	18,828	17,158	131,581	83,323	51,737
Operating expenses:	'	'	'	'	'	'	'	'	'	'	'
Sales and marketing	31,852	28,601	26,274	23,010	21,280	18,624	17,422	16,237	109,737	73,563	45,773
Research and development	5,893	5,716	5,232	4,419	4,261	4,101	3,431	3,093	21,260	14,886	10,149
General and administrative	9,215	8,261	7,530	8,566	7,566	6,600	5,792	5,954	33,572	25,912	15,122
Amortization of certain acquired intangible assets	251	251	251	251	251	251	237	0	1,004	739	0
Total operating expenses	47,211	42,829	39,287	36,246	33,358	29,576	26,882	25,284	165,573	115,100	71,044
Loss from operations	-7,843	-8,203	-8,105	-9,841	-7,654	-7,943	-8,054	-8,126	-33,992	-31,777	-19,307
Other income (expense):	'	'	'	'	'	'	'	'	'	'	'
Interest income (expense) and other income (expense), net	-3,009	-2,747	-714	-92	-2	18	-514	96	'	'	'
Loss before income tax benefit (provision)	-10,852	-10,950	-8,819	-9,933	-7,656	-7,925	-8,568	-8,030	-40,554	-32,179	-63,719
Income tax benefit (provision)	97	-104	136	-1	239	298	334	-82	128	789	-181
Net loss	($10,755)	($11,054)	($8,683)	($9,934)	($7,417)	($7,627)	($8,234)	($8,112)	($40,426)	($31,390)	($63,900)
Net loss per share attributable to common stockholders, basic and diluted	($0.21)	($0.21)	($0.17)	($0.20)	($0.15)	($0.15)	($0.17)	($0.16)	($0.79)	($0.63)	($1.74)
Weighted average common shares outstanding, basic and diluted	52,185	51,544	51,153	50,798	50,486	50,163	49,763	49,384	51,427	49,929	39,824

Investments_Details

Investments (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'
Available-for-sale Securities, Amortized Cost Basis	$265,495
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	135
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-5
Available-for-sale Securities	265,625
Money Market Funds	'
Schedule of Available-for-sale Securities [Line Items]	'
Available-for-sale Securities, Amortized Cost Basis	65,700
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0
Available-for-sale Securities	65,700
Corporate Bond Securities	'
Schedule of Available-for-sale Securities [Line Items]	'
Available-for-sale Securities, Amortized Cost Basis	78,488
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	121
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0
Available-for-sale Securities	78,609
Agency Securities	'
Schedule of Available-for-sale Securities [Line Items]	'
Available-for-sale Securities, Amortized Cost Basis	121,307
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	14
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-5
Available-for-sale Securities	$121,316