LivePerson (LPSN) 10-Q 7 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Nov. 03, 2014
Document - Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'lpsn	'
Entity Registrant Name	'LIVEPERSON INC	'
Entity Central Index Key	'0001102993	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	54,653,337

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$87,111	$91,906
Accounts receivable, net of allowance for doubtful accounts of $948 and $1,165 as of September 30, 2014 and December 31, 2013, respectively	32,386	29,489
Prepaid expenses and other current assets	9,620	6,361
Deferred tax assets, net	2,628	5,426
Total current assets	131,745	133,182
Property and equipment, net	18,763	17,618
Intangibles, net	14,020	13,088
Goodwill	35,783	32,724
Deferred tax assets, net	9,064	6,243
Other assets	2,342	2,235
Total assets	211,717	205,090
CURRENT LIABILITIES:	'	'
Accounts payable	8,932	10,139
Accrued expenses	29,752	25,419
Deferred revenue	14,022	8,747
Total current liabilities	52,706	44,305
Deferred revenue, net of current	0	468
Other liabilities	768	1,264
Total liabilities	53,474	46,037
Commitments and contingencies (See Note 11)	'	'
STOCKHOLDERS’ EQUITY (See Note 12):	'	'
Common stock	55	54
Additional paid-in capital	246,906	244,621
Treasury Stock, Value	-1	0
Accumulated deficit	-88,425	-85,279
Accumulated other comprehensive loss	-292	-343
Total stockholders’ equity	158,243	159,053
Total liabilities and stockholders’ equity	$211,717	$205,090

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Accounts receivable, allowance for doubtful accounts	$948	$1,165

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Revenue	$52,787		$45,192		$151,702		$130,917
Costs and expenses (1) (2)	'		'		'		'
Cost of revenue	13,304	[1],[2]	10,597	[1],[2]	38,200	[1],[2]	31,342	[1],[2]
Sales and marketing	20,978	[1],[2]	16,141	[1],[2]	59,449	[1],[2]	46,118	[1],[2]
Product development	9,712	[1],[2]	10,023	[1],[2]	27,999	[1],[2]	27,091	[1],[2]
General and administrative	8,787	[1],[2]	9,508	[1],[2]	28,074	[1],[2]	29,581	[1],[2]
Amortization of purchased intangibles	407		224		803		672
Total costs and expenses	53,188		46,493		154,525		134,804
Loss from operations	-401		-1,301		-2,823		-3,887
Other income, net	223		209		184		264
Loss before provision for (benefit from) income taxes	-178		-1,092		-2,639		-3,623
Provision for (benefit from) income taxes	962		-362		507		-832
Net loss	-1,140		-730		-3,146		-2,791
Basic net (loss) income per common share (in dollars per share)	($0.02)		($0.01)		($0.06)		($0.05)
Diluted net (loss) income per common share (in dollars per share)	($0.02)		($0.01)		($0.06)		($0.05)
Weighted average shares outstanding used in basic net (loss) income per common share calculation (in shares)	53,868,124		54,046,161		54,238,536		54,898,974
Weighted average shares outstanding used in diluted net (loss) income per common share calculation (in shares)	53,868,124		54,046,161		54,238,536		54,898,974
Stock compensation expense	3,654		3,798		9,558		9,749
Cost of revenue [Member]	'		'		'		'
Costs and expenses (1) (2)	'		'		'		'
Stock compensation expense	365		635		1,209		1,557
Depreciation expense	1,732		1,445		4,776		4,565
Sales and marketing expense [Member]	'		'		'		'
Costs and expenses (1) (2)	'		'		'		'
Stock compensation expense	1,030		844		2,766		2,159
Depreciation expense	195		23		603		68
Product development expense [Member]	'		'		'		'
Costs and expenses (1) (2)	'		'		'		'
Stock compensation expense	1,171		1,241		2,783		2,922
Depreciation expense	180		166		529		526
General and administrative expense [Member]	'		'		'		'
Costs and expenses (1) (2)	'		'		'		'
Stock compensation expense	1,088		1,078		2,800		3,111
Depreciation expense	$237		$368		$651		$891
[1]	Amounts include stock compensation expense as follows: Cost of revenue $365 and $635 for the three months ended September 30, 2014 and 2013, respectively and $1209 and $1557 for the nine months ended September 30, 2014 and 2013, respectively, Sales and marketing $1030 and $844 for the three months ended September 30, 2014 and 2013, respectively and $2,766 and $2,159 for the nine months ended September 30, 2014 and 2013, respectively, Product development $1,171 and $1,241 for the three months ended September 30, 2014 and 2013, respectively and $2,783 and $2,922 for the nine months ended September 30, 2014 and 2013, respectively, and General and administrative $1,088 and $1,078 for the three months ended September 30, 2014 and 2013, respectively and $2,800 and $3,111 for the nine months ended September 30, 2014 and 2013, respectively.
[2]	Amounts include depreciation expense as follows: Cost of revenue $1,732 and $1,445 for the three months ended September 30, 2014 and 2013, respectively and $4,776 and $4,565 for the nine months ended September 30, 2014 and 2013, respectively, Sales and marketing $195 and $23 for the three months ended September 30, 2014 and 2013, respectively and $603 and $68 for the nine months ended September 30, 2014 and 2013, respectively, Product development $180 and $166 for the three months ended September 30, 2014 and 2013, respectively and $529 and $526 for the nine months ended September 30, 2014 and 2013, respectively, and General and administrative $237 and $368 for the three months ended September 30, 2014 and 2013, respectively and $651 and $891 for the nine months ended September 30, 2014 and 2013, respectively.

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net loss	($1,140)	($730)	($3,146)	($2,791)
Foreign currency translation adjustment	-387	358	51	-29
Comprehensive loss	($1,527)	($372)	($3,095)	($2,820)

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
OPERATING ACTIVITIES:	'	'
Net loss	($3,146)	($2,791)
Adjustments to reconcile net loss to net cash provided by operating activities:	'	'
Stock-based compensation expense	9,558	9,749
Depreciation	6,559	6,050
Amortization of purchased intangibles	3,461	1,575
Deferred income taxes and other non-cash tax items	-1,067	-1,700
Provision for doubtful accounts, net	1,096	0
Changes in operating assets and liabilities:	'	'
Accounts receivable	-4,337	-7,395
Prepaid expenses and other current assets	-4,390	-1,523
Other assets	538	79
Accounts payable	-2,248	-3,523
Accrued expenses	3,873	2,978
Deferred revenue	5,003	261
Other liabilities	-469	-112
Net cash provided by operating activities	14,431	3,648
INVESTING ACTIVITIES:	'	'
Purchases of property and equipment, including capitalized software	-6,644	-6,638
Investment in technology licenses	-3,451	0
Acquisition of Synchronite	-2,300	0
Acquisition of NexGraph	-125	0
Acquisition of domains	-27	-50
Acquisition costs - Engage, net of cash	0	-79
Net cash used in investing activities	-12,547	-6,767
FINANCING ACTIVITIES:	'	'
Excess tax benefit from the exercise of employee stock options	0	135
Proceeds from issuance of common stock in connection with the exercise of options	6,109	3,737
Repurchase of common stock	-12,980	-26,716
Net cash used in financing activities	-6,871	-22,844
EFFECT OF FOREIGN EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	192	3
CHANGE IN CASH AND CASH EQUIVALENTS	-4,795	-25,960
CASH AND CASH EQUIVALENTS - Beginning of the period	91,906	103,339
CASH AND CASH EQUIVALENTS - End of the period	87,111	77,379
SUPPLEMENTAL DISCLOSURE OF OTHER CASH FLOW INFORMATION:	'	'
Cash paid for income taxes	2,182	151
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:	'	'
Contingent earn-out in connection with the acquisition of Synchronite recorded in accrued expenses	1,810	0
Purchase of property and equipment recorded in accounts payable	1,840	720
Acquisition cost in connection with NexGraph recorded in accrued expenses	$125	$0

Description_of_Business_and_Ba

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Description of Business and Basis of Presentation	'
	Description of Business and Basis of Presentation
	LivePerson, Inc. (the “Company” or “LivePerson”) was incorporated in the State of Delaware in November 1995 and the LivePerson service was introduced in November 1998. In April 2000, the Company completed an initial public offering and is currently traded on the Nasdaq Global Select Market and the Tel Aviv Stock Exchange. LivePerson is headquartered in New York City with offices in Amsterdam, Atlanta, London, Melbourne, San Francisco, Tokyo and Tel Aviv.
	LivePerson provides online engagement solutions offering a cloud-based platform which enables businesses to proactively connect with consumers through chat, voice and content delivery, across multiple channels and screens, including websites, social media, tablets and mobile devices. The Company’s engagements are driven by insights derived from a broad set of consumer and business data, including historical, behavioral, operational, and third party data. Each engagement is based on proprietary analytics and a real-time understanding of consumer needs and business objectives. The Company’s products, coupled with its domain knowledge and industry expertise, have been proven to maximize the effectiveness of the online channel — by increasing sales, as well as consumer satisfaction and loyalty ratings for its customers, while also enabling its customers to reduce consumer service costs.
	LivePerson monitors and analyzes valuable online consumer behavioral data on behalf of its customers. Spanning the breadth of an online visitor session, starting from an initial keyword search through actions on their customer’s website, and even into a shopping cart and an executed sale, this data enables the Company to develop unique insights into consumer behavior during specific transactions within a customer’s user base.
	The Company’s primary revenue source is from the sale of LivePerson services to businesses of all sizes. The Company also offers an online marketplace that connects independent service providers (“Experts”) who provide information and knowledge for a fee via real-time chat with individual consumers (“Users”).
	Basis of Presentation
	The accompanying condensed consolidated financial statements as of September 30, 2014 and for the three and nine months ended September 30, 2014 and 2013 are unaudited. In the opinion of management, the unaudited condensed consolidated financial statements have been prepared on the same basis as the annual financial statements and reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the consolidated financial position of LivePerson as of September 30, 2014, and the consolidated results of operations, comprehensive loss and cash flows for the interim periods ended September 30, 2014 and 2013. The financial data and other information disclosed in these notes to the condensed consolidated financial statements related to these periods are unaudited. The results of operations for any interim period are not necessarily indicative of the results of operations for any other future interim period or for a full fiscal year. The condensed consolidated balance sheet at December 31, 2013 has been derived from audited consolidated financial statements at that date.
	Certain information and note disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). These unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2013, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 14, 2014.
	Reclassification
	For comparability, certain 2013 amounts have been reclassified where appropriate, to conform to the financial presentation in 2014.
	Principles of Consolidation
	The condensed consolidated financial statements include the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated.
	Use of Estimates
	The preparation of the Company’s condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of income and expenses during the reporting period. These estimates are based on information available as of the date of the condensed consolidated financial statements; therefore, actual results could differ from management’s estimates.
	Recently Issued Accounting Standards
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), which supersedes most existing revenue recognition guidance under GAAP. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. ASU 2014-09 defines a five step process to achieve this core principle and, in doing so, more judgment and estimates may be required within the revenue recognition process than are required under existing GAAP.
	The standard is effective for annual periods beginning after December 15, 2016, and interim periods therein, using either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (ii) a retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures).  The Company is currently evaluating the impact of the Company’s pending adoption of ASU 2014-09 on our consolidated financial statements and have not yet determined the method by which it will adopt the standard in 2017.

Revenue_Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2014
Revenue Recognition [Abstract]	'
Revenue Recognition	'
	Revenue Recognition
	The majority of the Company’s revenue is generated from monthly service revenues and related professional services from the sale of the LivePerson services. Because the Company provides its application as a service, the Company follows the provisions of FASB Accounting Standards Codification (“ASC”) 605-10-S99, “Revenue Recognition” and ASC 605-25, “Revenue Recognition with Multiple-Element Arrangements.” The Company charges a monthly fee, which varies by type of service, the level of customer usage and website traffic, and in some cases, the number of orders placed via the Company’s online engagement solutions.
	For certain of the Company’s larger customers, the Company may provide call center labor through an arrangement with one or more of several qualified vendors. For most of these customers, the Company passes the fee it incurs with the labor provider and its fee for the hosted services through to its customers in the form of a fixed fee for each order placed via the Company’s online engagement solutions. For these Pay for Performance (“PFP”) arrangements, in accordance with ASC 605-45, “Principal Agent Considerations,” the Company records revenue for transactions in which it acts as an agent on a net basis, and revenue for transactions in which it acts as a principal on a gross basis.
	The Company also sells certain of the LivePerson services directly via Internet download.  These services are marketed as LiveEngage for small to medium-sized businesses (“SMBs”), and are paid for almost exclusively by credit card.  Credit card payments accelerate cash flow and reduce the Company’s collection risk, subject to the merchant bank's right to hold back cash pending settlement of the transactions.  Sales of LiveEngage may occur with or without the assistance of an online sales representative, rather than through face-to-face or telephone contact that is typically required for traditional direct sales.
	The Company recognizes monthly service revenue based upon the fee charged for the LivePerson services, provided that there is persuasive evidence of an arrangement, no significant Company obligations remain, collection of the resulting receivable is probable and the amount of fees to be paid is fixed or determinable. The Company’s service agreements typically have twelve month terms and, in some cases, are terminable or may terminate upon 30 to 90 days’ notice without penalty. When professional service fees add value to the customer on a standalone basis, the Company recognizes professional service fees upon completion and customer acceptance in accordance with FASB Accounting Standards Update 2009-13. This guidance establishes a selling price hierarchy for determining the selling price of a deliverable, which is based on: (a) vendor-specific objective evidence; (b) third-party evidence; or (c) best estimated selling price. If a professional services arrangement does not qualify for separate accounting, the Company recognizes the fees, and the related labor costs, ratably over the contracted period.
	For revenue generated from online transactions between Experts and Users, the Company recognizes revenue net of the Expert fees in accordance with ASC 605-45, “Principal Agent Considerations,” due primarily to the fact that the Expert is the primary obligor. Additionally, the Company performs as an agent without any risk of loss for collection, and is not involved in selecting the Expert or establishing the Expert’s fee. The Company collects a fee from the User and retains a portion of the fee, and then remits the balance to the Expert. Revenue from these transactions is recognized when there is persuasive evidence of an arrangement, no significant Company obligations remain, collection of the resulting receivable is probable and the amount of fees to be paid is fixed and determinable.

Net_Loss_Per_Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Net Loss Per Share	'
	Net Loss Per Share
	The Company calculates earnings per share (“EPS”) in accordance with the provisions of ASC 260-10 and the guidance of SEC Staff Accounting Bulletin (“SAB”) No. 98. Under ASC 260-10, basic EPS excludes dilution for common stock equivalents and is computed by dividing net income or loss attributable to common shareholders by the weighted average number of common shares outstanding for the period. All options, warrants or other potentially dilutive instruments issued for nominal consideration are required to be included in the calculation of basic and diluted net income attributable to common stockholders. Diluted EPS is calculated using the treasury stock method and reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock and resulted in the issuance of common stock.
	Diluted net loss per common share for the three and nine months ended September 30, 2014 does not include the effect of options to purchase 11,127,640 shares of common stock as the effect of their inclusion is anti-dilutive. Diluted net loss per common share for the three and nine months ended September 30, 2013 does not include the effect of options to purchase 10,132,045 shares of common stock as the effect of their inclusion is anti-dilutive.
	A reconciliation of shares used in calculating basic and diluted earnings per share follows:
		Three Months Ended		Nine Months Ended
		September 30,		September 30,
		2014	2013	2014	2013
	Basic	53,868,124	54,046,161	54,238,536	54,898,974
	Effect of assumed exercised options	—	—	—	—
	Diluted	53,868,124	54,046,161	54,238,536	54,898,974

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	The Company accounts for its segment information in accordance with the provisions of ASC 280-10, “Segment Reporting.” ASC 280-10 establishes annual and interim reporting standards for operating segments of a company. ASC 280-10 requires disclosures of selected segment-related financial information about products, major customers, and geographic areas based on the Company’s internal accounting methods. The Company is organized into two operating segments for purposes of making operating decisions and assessing performance. The Business segment facilitates real-time online interactions – chat, voice and content delivery across multiple channels and screens for global corporations of all sizes. The Consumer segment facilitates online transactions between Experts and Users and sells its services to consumers. Both segments currently generate their revenue primarily in the United States. The chief operating decision makers evaluate performance, make operating decisions, and allocate resources based on the operating income of each segment. The reporting segments follow the same accounting polices used in the preparation of the Company’s condensed consolidated financial statements which are described in the summary of significant accounting policies. The Company allocates cost of revenue, sales and marketing and amortization of purchased intangibles to the segments, but it does not allocate product development expenses, general and administrative expenses and income tax expense because management does not use this information to measure performance of the operating segments. There are currently no inter-segment sales.
	Summarized financial information by segment for the three months ended September 30, 2014, based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision makers, follows (amounts in thousands):
		Business		Consumer		Corporate			Consolidated
	Revenue:
	Hosted services – Business	$	43,702	$	—	$	—		$	43,702
	Hosted services – Consumer	—		3,992		—			3,992
	Professional services	5,093		—		—			5,093
	Total revenue	48,795		3,992		—			52,787
	Cost of revenue	12,679		625		—			13,304
	Sales and marketing	19,488		1,490		—			20,978
	Amortization of purchased intangibles	407		—		—			407
	Unallocated corporate expenses	—		—		18,499			18,499
	Operating income (loss)	$	16,221	$	1,877	$	(18,499	)	$	(401	)
	Summarized financial information by segment for the three months ended September 30, 2013, based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision makers, follows (amounts in thousands):
		Business		Consumer		Corporate			Consolidated
	Revenue:
	Hosted services – Business	$	38,007	$	—	$	—		$	38,007
	Hosted services – Consumer	—		3,828		—			3,828
	Professional services	3,357		—		—			3,357
	Total revenue	41,364		3,828		—			45,192
	Cost of revenue	10,014		583		—			10,597
	Sales and marketing	14,664		1,477		—			16,141
	Amortization of purchased intangibles	224		—		—			224
	Unallocated corporate expenses	—		—		19,531			19,531
	Operating income (loss)	$	16,462	$	1,768	$	(19,531	)	$	(1,301	)
	Summarized financial information by segment for the nine months ended September 30, 2014, based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision makers, follows (amounts in thousands):
		Business		Consumer		Corporate			Consolidated
	Revenue:
	Hosted services – Business	$	125,378	$	—	$	—		$	125,378
	Hosted services – Consumer	—		12,441		—			12,441
	Professional services	13,883		—		—			13,883
	Total revenue	139,261		12,441		—			151,702
	Cost of revenue	36,306		1,894		—			38,200
	Sales and marketing	55,203		4,246		—			59,449
	Amortization of purchased intangibles	803		—		—			803
	Unallocated corporate expenses	—		—		56,073			56,073
	Operating income (loss)	$	46,949	$	6,301	$	(56,073	)	$	(2,823	)
	Summarized financial information by segment for the nine months ended September 30, 2013, based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision makers, follows (amounts in thousands):
		Business		Consumer		Corporate			Consolidated
	Revenue:
	Hosted services – Business	$	110,785	$	—	$	—		$	110,785
	Hosted services – Consumer	—		11,223		—			11,223
	Professional services	8,909		—		—			8,909
	Total revenue	119,694		11,223		—			130,917
	Cost of revenue	29,524		1,818		—			31,342
	Sales and marketing	42,113		4,005		—			46,118
	Amortization of purchased intangibles	672		—		—			672
	Unallocated corporate expenses	—		—		56,672			56,672
	Operating income (loss)	$	47,385	$	5,400	$	(56,672	)	$	(3,887	)
	Geographic Information
	The Company is domiciled in the United States and has international operations in the United Kingdom, Asia-Pacific, Latin America and Western Europe, particularly France and Germany. The following table presents the Company’s revenues attributable to domestic and foreign operations for the periods presented (amounts in thousands):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014			2013
	United States	$	34,409	$	28,947	$	99,273		$	86,553
	Other Americas (1)	2,936		2,353		7,259			6,145
	Total Americas	37,345		31,300		106,532			92,698
	EMEA (2)	11,049		9,600		32,618			25,572
	APAC (3)	4,393		4,292		12,552			12,647
	Total revenue	$	52,787	$	45,192	$	151,702		$	130,917
	(1) Canada, Latin America and South America
	(2) Europe, the Middle East and Africa (“EMEA”)
(3) Asia-Pacific (“APAC”)
The following table presents the Company's long-lived assets by geographic region for the periods presented (amounts in thousands):
	September 30,		December 31,
	2014		2013
United States	$	42,066	$	34,422
Israel	19,700		22,580
Australia	8,858		9,827
Netherlands	7,687		3,540
Other (1)	1,661		1,539
Total long-lived assets	$	79,972	$	71,908
(1) United Kingdom, Germany and Japan
No individual customer accounted for 10% or more of consolidated revenue for any of the periods presented. One customer accounted for approximately 22% and 12% of accounts receivable as of September 30, 2014 and December 31, 2013, respectively.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets	'
	Goodwill and Intangible Assets
	Goodwill
	The changes in the carrying amount of goodwill for the nine months ended September 30, 2014 are as follows (amounts in thousands):
		Business		Consumer			Total
	Balance as of December 31, 2013	$	24,700	$	8,024		$	32,724
	Adjustments to goodwill:
	NexGraph acquisition	400		—			400
	Synchronite acquisition	2,659		—			2,659
	Balance as of September 30, 2014	$	27,759	$	8,024		$	35,783
	The changes in the carrying amount of goodwill for the year ended December 31, 2013 are as follows (amounts in thousands):
		Business		Consumer			Total
	Balance as of December 31, 2012	$	24,621	$	8,024		$	32,645
	Adjustments to goodwill:
	Adjustments to Engage acquisition	79		—			79
	Balance as of December 31, 2013	$	24,700	$	8,024		$	32,724
	Intangible Assets
	Intangible assets are summarized as follows (see Note 8 and Note 10) (amounts in thousands):
		As of September 30, 2014
		Gross		Accumulated			Net Carrying Amount		Weighted
		Carrying		Amortization					Average
		Amount							Amortization
									Period
	Amortizing intangible assets:
	Technology	$	19,615	$	(10,320	)	$	9,295	4.1 years
	Customer relationships	5,308		(3,658		)	1,650		3.7 years
	Trade names	787		(730		)	57		2.8 years
	Non-compete agreements	646		(551		)	95		1.3 years
	Patents	3,290		(416		)	2,874		9.9 years
	Other	312		(263		)	49		3.0 years
	Total	$	29,958	$	(15,938	)	$	14,020
		As of December 31, 2013
		Gross		Accumulated			Net Carrying Amount		Weighted
		Carrying		Amortization					Average
		Amount							Amortization
									Period
	Amortizing intangible assets:
	Technology	$	18,533	$	(7,678	)	$	10,855	3.8 years
	Customer relationships	5,061		(3,148		)	1,913		3.5 years
	Trade names	725		(725		)	—		2.7 years
	Non-compete agreements	486		(486		)	—		1.2 years
	Patents	475		(189		)	286		11.0 years
	Other	285		(251		)	34		3.0 years
	Total	$	25,565	$	(12,477	)	$	13,088
	Amortization expense is calculated on a straight-line basis over the estimated useful life of the asset. Aggregate amortization expense for intangible assets was $1.3 million and $3.5 million for the three and nine months ended September 30, 2014, respectively. Aggregate amortization expense for intangible assets was $0.7 million and $1.6 million for the three and nine months ended September 30, 2013, respectively. For the three and nine months ended September 30, 2014, a portion of this amortization is included in cost of revenue. Estimated amortization expense for the next five years are as follows (amounts in thousands):
		Estimated Amortization Expense
	2014	$	1,135
	2015	4,267
	2016	3,805
	2017	2,205
	2018	485
	Thereafter	2,123
	Total	$	14,020

Property_and_Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Property and Equipment	'
	Property and Equipment
	The following table presents the detail of property and equipment for the periods presented (amounts in thousands):
		September 30,			December 31,
		2014			2013
	Computer equipment and software	$	52,322		$	45,790
	Furniture, equipment and building improvements	9,078			7,906
		61,400			53,696
	Less: accumulated depreciation	(42,637		)	(36,078		)
	Total	$	18,763		$	17,618

Accrued_Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2014
Payables and Accruals [Abstract]	'
Accrued Liabilities	'
	Accrued Liabilities
	The following table presents the detail of accrued liabilities for the periods presented (amounts in thousands):
		September 30,		December 31,
		2014		2013
	Payroll and other employee related costs	$	12,310	$	13,090
	Professional services and consulting and other vendor fees	9,427		6,769
	Sales commissions	2,733		1,778
	Contingent earnout (Note 8)	2,970		1,660
	Other	2,312		2,122
	Total	$	29,752	$	25,419

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions
	Amadesa Ltd.
	On May 31, 2012, the Company acquired technology assets from Amadesa, Ltd., an Israeli-based start-up, for aggregate cash consideration of approximately $10.3 million. The acquisition provides the Company with sophisticated, machine-learning predictive modeling that it expects to leverage across multiple engagement channels, enhancing its real-time intelligent engagement platform. The asset was allocated to “Intangibles, net” on the Company’s condensed consolidated balance sheet and is being amortized over its expected period of benefit. The acquisition did not have a material impact on the Company’s reported operating results. Total acquisition costs incurred were approximately $0.5 million and are included in “Intangibles, net” on the Company’s condensed consolidated balance sheet.
	LookIO, Inc.
	On June 13, 2012, the Company acquired LookIO, Inc., a start-up that provides mobile engagement solutions. The transaction was accounted for under the purchase method of accounting and, accordingly, the operating results of LookIO, Inc. were included in the Company’s consolidated results of operations from the date of acquisition. The acquisition did not have a material impact on the Company’s reported operating results.
	The purchase price was approximately $2.9 million, which included the issuance of 109,517 shares of the Company’s common stock valued at approximately $2.0 million, based on the quoted market price of the Company’s common stock on the day of closing, and a cash payment of $0.9 million. Total acquisition costs incurred were approximately $0.2 million and were included in general and administrative expenses in the Company’s condensed consolidated statements of operations. The acquisition adds plug-and-play mobile engagement capabilities to LivePerson’s platform allowing its customers to connect with consumers on mobile devices. All 109,517 shares are included in the weighted average shares outstanding used in basic and diluted net income (loss) per share as of the acquisition date. The purchase price was allocated based on management’s estimate of fair values, taking into account all relevant information available. A substantial amount of the purchase price was allocated to intangibles (technology) and the excess was allocated to goodwill. The goodwill is not deductible for income tax purposes. The intangible asset is being amortized over its expected period of benefit. In addition to the purchase price, certain founders can earn an additional 30,422 shares of LivePerson common stock by achieving an employment milestone by providing continued services through a specified date, of which 25,961 shares were earned. The Company valued these potential earn-out shares at approximately $0.6 million, based on the quoted market price of the Company’s common stock on the day of closing.
	Management’s allocation of the purchase price in connection with the LookIO acquisition is as follows (amounts in thousands):
	Intangible assets (technology)	$	767
	Goodwill	2,405
		3,172
	Deferred tax liability	(288		)
	Total purchase price consideration	$	2,884
	Engage Pty Ltd.
	On November 9, 2012, the Company acquired all outstanding shares of Engage Pty Ltd. (“Engage”), an Australian provider of cloud-based customer contact solutions. The transaction was accounted for under the purchase method of accounting and, accordingly, the operating results of Engage were included in the Company’s consolidated results of operations from the date of acquisition. The acquisition did not have a material impact on the Company’s reported operating results.
	The purchase price was approximately $10.6 million. The total acquisition costs incurred in the year ended December 31, 2012 were approximately $0.5 million and are included in general and administrative expenses in the Company’s condensed consolidated statements of operations for the same period. The acquisition enhances the Company’s ability to offer intelligent engagement solutions to businesses in the Asia Pacific region. Of the total purchase price, $0.8 million was allocated to the net book values of the acquired assets and assumed liabilities. The historical carrying amounts of such assets and liabilities approximated their fair values. All receivables acquired are expected to be collectible. The purchase price in excess of the fair value of the net book values of the assets acquired and liabilities assumed was allocated to intangible assets based on management’s best estimate of fair values, taking into account all relevant information available at the time of acquisition, and the excess was allocated to goodwill. The goodwill is not deductible for tax purposes. The intangible assets are being amortized over their expected period of benefit. The purchase price includes approximately $1.6 million of potential earn-out consideration for the shareholders if certain revenue targets are achieved. The earn-out is payable in shares of LivePerson common stock. The Company recorded the contingent earn-out as part of the purchase price. In accordance with ASC 480, the Company has classified this amount as a liability and the amount is included in accrued expenses in the September 30, 2014 balance sheet, due to the variable number of shares that will be issued if and when the targets are achieved. During 2014, the Company paid $0.5 million of the total potential earn-out consideration amount. The Company will assess the earn-out calculation in future periods and any future adjustments will affect operating income.
	Management’s preliminary allocation of the purchase price in connection with the Engage acquisition is as follows (amounts in thousands):
	Cash	$	386
	Accounts receivable	3,454
	Other current assets	57
	Property and equipment	432
	Other assets	104
	Intangible assets	3,600
	Goodwill	6,152
		14,185
	Liabilities assumed	(2,632		)
	Deferred tax liability	(962		)
	Total purchase price consideration	$	10,591
	The components of the intangible assets listed in the above table are as follows (amounts in thousands):
		Weighted		Amount
		Average Useful
		Life (Months)
	Technology	36		$	768
	Trade-name	12		95
	Customer relationships	48		2,661
	Non-compete agreements	12		76
				$	3,600
	NexGraph LLC
	In March 2014, the Company acquired all the outstanding shares of NexGraph LLC (“NexGraph”), a company focused on analytic solutions, in exchange for aggregate cash consideration of $0.5 million. This transaction was accounted for as an asset purchase. The $0.1 million was allocated to Intangibles, net and $0.4 million was allocated to Goodwill.
	Synchronite LLC
	On June 2, 2014, the Company acquired Synchronite LLC (“Synchronite”), a German based start-up that provides co-browsing technology. The transaction was accounted for under the purchase method of accounting and, accordingly, the operating results of Synchronite were included in the Company’s consolidated results of operations from the date of acquisition. The acquisition did not have a material impact on the Company’s reported operating results.
	The allocation of the total purchase price of approximately $4.1 million was based upon the estimated fair value of Synchronite's net tangible and identifiable intangible assets as of the date of acquisition. The total acquisition costs incurred were approximately $0.4 million and are included in general and administrative expenses in the Company’s condensed consolidated statements of operations. Of the total purchase price, $45,000 was allocated to the net book values of the acquired assets and assumed liabilities. The historical carrying amounts of such assets and liabilities approximated their fair values. All receivables acquired are expected to be collectible. The purchase price includes approximately $2.7 million of goodwill and approximately $1.5 million of intangible assets. The goodwill is not deductible for tax purposes. The intangible assets are being amortized over their expected period of benefit. The purchase price includes $1.8 million of potential earn-out consideration for the shareholders if complete product integration is achieved. The earn-out is payable in shares of LivePerson common stock and cash. The Company recorded the contingent earn-out as part of the purchase price. In accordance with ASC 480, the Company has classified this amount as a liability and the amount is included in accrued expenses in the September 30, 2014 condensed consolidated balance sheet, due to the variable number of shares that will be issued if and when the targets are achieved. The Company will assess the earn-out calculation in future periods and any future adjustments will affect operating income.
	The components of the intangible assets are as follows (amounts in thousands):
		Weighted		Amount
		Average Useful
		Life (Months)
	Technology	120		$	1,082
	Trade-name	48		62
	Customer relationships	84		247
	Non-compete agreements	36		60
				$	1,451

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The Company measures its cash equivalents at fair value based on an expected exit price as defined by the authoritative guidance on fair value measurements, which represents the amount that would be received on the sale of an asset or paid to transfer a liability, as the case may be, in an orderly transaction between market participants. As such, fair value may be based on assumptions that market participants would use in pricing an asset or liability. The authoritative guidance on fair value measurements establishes a consistent framework for measuring fair value on either a recurring or nonrecurring basis whereby inputs, used in valuation techniques, are assigned a hierarchical level. The following are the hierarchical levels of inputs to measure fair value:
	•	Level 1: Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.
	•	Level 2: Inputs reflect: quoted prices for identical assets or liabilities in markets that are not active; quoted prices for similar assets or liabilities in active markets; inputs other than quoted prices that are observable for the assets or liabilities; or inputs that are derived principally from or corroborated by observable market data by correlation or other means.
	•	Level 3: Unobservable inputs reflecting the Company’s assumptions incorporated in valuation techniques used to determine fair value. These assumptions are required to be consistent with market participant assumptions that are reasonably available.
	The Company's assets and liabilities that are measured at fair value on a recurring basis, by level, within the fair value hierarchy as of September 30, 2014 and December 31, 2013, are summarized as follows (amounts in thousands):
		September 30, 2014									December 31, 2013
		Level 1			Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Assets:
	Cash equivalents:
	Money market funds	$	12,608		$	—	$	—	$	12,608	$	13,674	$	—	$	—	$	13,674
	Total assets	$	12,608		$	—	$	—	$	12,608	$	13,674	$	—	$	—	$	13,674
	Liabilities:
	Contingent earn-out	$	—		$	—	$	2,970	$	2,970	$	—	$	—	$	1,660	$	1,660
	Total liabilities	$	—		$	—	$	2,970	$	2,970	$	—	$	—	$	1,660	$	1,660
	In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. Observable or market inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company's assumptions based on the best information available.
	The Company's only asset that is measured at fair value on a recurring basis is money market funds, based on quoted market prices in active markets and therefore classified as level 1 within the fair value hierarchy. The Company's only liability that is measured at fair value on a recurring basis is the contingent earn-out and is classified as level 3 within the fair value hierarchy. On a nonrecurring basis, the Company uses fair value measures when analyzing asset impairment. Long-lived tangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If it is determined such indicators are present and the review indicates that the assets will not be fully recoverable, based on undiscounted estimated cash flows over the remaining amortization periods, their carrying values are reduced to estimated fair value. The Company uses an income approach and inputs that constitute level 3.  During the third quarter of each year, the Company evaluates goodwill for impairment at the reporting unit level. The Company uses a combination of discounted cash flows and other qualitative factors in accordance with ASU No. 2011-08 to determine whether it is “more likely than not” that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test.  This measurement is classified based on level 3 input.
	The contingent earn-out in connection with the acquisition of Engage is $1.2 million and $1.7 million as of September 30, 2014 and December 31, 2013, respectively, and is recorded in accrued expenses in the condensed consolidated balance sheets. The earn-out is based on the potential earn-out consideration if certain revenue targets are achieved. The total contingent earn-out was increased by $1.8 million in June 2014 in connection with the acquisition of Synchronite and is also recorded in accrued expense on the condensed consolidated balance sheet as of September 30, 2014. The contingent earn-out is based on the fulfillment of a complete product integration and a minimum number of “Co-Browse” interactions per month.
	The changes in fair value of the Level 3 liabilities are as follows (amounts in thousands):
		Contingent Earn-Out
		30-Sep-14			31-Dec-13
	Balance, Beginning of Period	$	1,660		$	1,660
	Synchronite addition (see Note 8)	1,810			—
	Cash payment	(500		)	—
	Balance, End of Period	$	2,970		$	1,660

Investments

Investments	9 Months Ended
	Sep. 30, 2014
Investments, All Other Investments [Abstract]	'
Investments	'
	Investments
	In February 2014, the Company purchased technology licenses and consulting services at fair value from a company in the amount of $3.5 million. The Company will receive access to the company's patents as well as certain consulting services. During the three months ended September 30, 2014, the Company allocated approximately $2.8 million to intangible assets, which is being amortized over the life of the patents. The remaining amount was allocated to other assets.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Contractual Obligations
	The Company leases facilities and certain equipment under agreements accounted for as operating leases. These leases generally require the Company to pay all executory costs such as maintenance and insurance. Rental expense for operating leases for the three and nine months ended September 30, 2014 was approximately $2.3 million and $6.9 million, respectively. Rental expense for operating leases for the three and nine months ended September 30, 2013 was approximately $2.2 million and $6.9 million, respectively.
	Employee Benefit Plans
	The Company has a 401(k) defined contribution plan covering all eligible employees. The Company provides for employer matching contributions equal to 50% of employee contributions, up to the lesser of 5% of eligible compensation or $6,000. Matching contributions are deposited into the employee’s 401(k) account and are subject to 5 year graded vesting. Salaries and related expenses include $0.2 million and $0.8 million of employer matching contributions for the three and nine months ended September 30, 2014, respectively. Salaries and related expenses include $0.2 million and $0.7 million of employer matching contributions for the three and nine months ended September 30, 2013, respectively.

Stockholders_Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stockholders' Equity	'
	Stockholders' Equity
	Common Stock
	As of September 30, 2014, there were 100,000,000 shares of common stock authorized, and 54,584,170 shares issued and outstanding. As of December 31, 2013, there were 100,000,000 shares of common stock authorized, and 54,484,760 shares issued and outstanding. The par value for common shares is $0.001.
	Preferred Stock
	As of September 30, 2014 and December 31, 2013, there were 5,000,000 shares of preferred stock authorized, and zero shares issued and outstanding. The par value for preferred shares is $0.001.
	Stock Repurchase Program
	On December 10, 2012, the Company’s Board of Directors approved a stock repurchase program through June 30, 2014. Under the stock repurchase program, the Company is authorized to repurchase shares of its common stock, in the open market or privately negotiated transactions, at times and prices considered appropriate by the Board of Directors depending upon prevailing market conditions and other corporate considerations. On March 13, 2014, the Company's Board of Directors increased the aggregate purchase price of the stock repurchase program from $30.0 million to $40.0 million. On July 23, 2014, the Company's Board of Directors extended the expiration date of the program out to December 31, 2014 and also increased the aggregate purchase price of the stock repurchase program from $40.0 million to $50.0 million. There were 1,195,185 shares repurchased under this program during 2014, of which 544,396 shares were recorded in treasury stock at par on the condensed consolidated balance sheets as of September 30, 2014. As of September 30, 2014, approximately $10.3 million remained available for purchase under the program.
	Stock-Based Compensation
	The Company follows FASB ASC 718-10, “Stock Compensation,” which addresses the accounting for transactions in which an entity exchanges its equity instruments for goods or services, with a primary focus on transactions in which an entity obtains employee services in share-based payment transactions. ASC 718-10 requires measurement of the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award (with limited exceptions). Incremental compensation costs arising from subsequent modifications of awards after the grant date must be recognized.
	The following table summarizes stock-based compensation expense related to employee stock options under ASC 718-10 included in Company’s statements of operations for the periods presented (amounts in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2014				2013				2014			2013
	Cost of revenue	$	365			$	635			$	1,209		$	1,557
	Sales and marketing expense	1,030				844				2,766			2,159
	Product development expense	1,171				1,241				2,783			2,922
	General and administrative expense	1,088				1,078				2,800			3,111
	Total stock based compensation included in costs and expenses	$	3,654			$	3,798			$	9,558		$	9,749
	The per share weighted average fair value of stock options granted during the three and nine months ended September 30, 2014 was $4.57 and $4.99, respectively. The per share weighted average fair value of stock options granted during the three and nine months ended September 30, 2013 was $4.82 and $5.25, respectively. The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
	Dividend yield	0.00%		0.00%		0.00%		0.00%
	Risk-free interest rate	1.70%		1.40%		1.5% - 1.7%		0.7% - 1.4%
	Expected life (in years)	5		5		5		5
	Historical volatility	50.90%		59.8% - 59.9%		50.9% - 53.7%		56.7% - 60.1%
	A description of the methods used in the significant assumptions used to estimate the fair value of stock-based compensation awards follows:
	Dividend yield – The Company uses 0% as it has never issued dividends and does not anticipate issuing dividends in the near term.
	Risk-free interest rate – The Company uses the market yield on U.S. Treasury securities at five years with constant maturity, representing the current expected life of stock options in years.
	Expected life – The Company uses historical data to estimate the expected life of a stock option.
	Historical volatility – The Company uses a trailing five year from grant date to determine volatility.
	Stock Option Plans
	During 1998, the Company established the Stock Option and Restricted Stock Purchase Plan (the “1998 Plan”). Under the 1998 Plan, the Board of Directors could issue incentive stock options or nonqualified stock options to purchase up to 5,850,000 shares of common stock. The 2000 Stock Incentive Plan (the “2000 Plan”) succeeded the 1998 Plan. Under the 2000 Plan, the options which had been outstanding under the 1998 Plan were incorporated in the 2000 Plan increasing the number of shares available for issuance under the plan by approximately 4,150,000, thereby reserving for issuance 10,000,000 shares of common stock in the aggregate.
	The Company established the 2009 Stock Incentive Plan (as amended and restated, the “2009 Plan”) as a successor to the 2000 Plan. Under the 2009 Plan, the options which had been outstanding under the 2000 Plan were incorporated into the 2009 Plan and the Company increased the number of shares available for issuance under the plan by 6,000,000. The Company amended the 2009 stock incentive plan (the “Amended 2009 Plan”) effective June 7, 2012. The Amended 2009 Plan increased the number of shares authorized for issuance under the plan by an additional 4,250,000, thereby reserving for issuance 23,817,744 shares of common stock in the aggregate. Options to acquire common stock granted thereunder have 10-year terms. As of September 30, 2014, approximately 13,995,000 shares of common stock were reserved for issuance under the 2009 Plan (taking into account all option exercises through September 30, 2014).
	Employee Stock Purchase Plan
	In June 2010, the Company’s stockholders approved the 2010 Employee Stock Purchase Plan with 1,000,000 shares of common stock initially reserved for issuance. As of September 30, 2014, approximately 582,000 shares of common stock were reserved for issuance under the Employee Stock Purchase Plan (taking into account all share purchases through September 30, 2014).
	Stock Option Activity
	A summary of the Company’s stock option activity and weighted average exercise prices follows:
		Stock Option Activity							Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
		Options			Weighted
					Average
					Exercise Price
	Balance outstanding at December 31, 2013	9,724,193			$	10.86
	Granted	3,289,700			10.63
	Exercised	(565,668	)		7.77
	Cancelled or expired	(1,320,585	)		12.8
	Balance outstanding at September 30, 2014	11,127,640			$	10.68			7.14		$	29,989
	Options vested and expected to vest at September 30, 2014	9,300,501			$	10.64			6.78		$	26,214
	Options exercisable at September 30, 2014	5,034,974			$	9.69			5.33		$	19,268
	The total fair value of stock options exercised during the nine months ended September 30, 2014 was approximately $2.5 million. As of September 30, 2014, there was approximately $30.3 million of total unrecognized compensation cost related to nonvested share-based compensation arrangements. That cost is expected to be recognized over a weighted average period of approximately 2.8 years.
	A summary of the status of the Company’s nonvested shares as of December 31, 2013, and changes during the nine months ended September 30, 2014 is as follows:
		Options			Weighted
					Average Grant-
					Date Fair Value
	Nonvested Shares at December 31, 2013	5,633,701			$	6.9
	Granted	3,289,700			4.99
	Vested	(1,510,150	)		6.09
	Cancelled or expired	(1,320,585	)		6.49
	Nonvested Shares at September 30, 2014	6,092,666			$	5.65

Subsequent_Event

Subsequent Event	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Event	'
	Subsequent Event
	Contact At Once!, LLC
	On November 5, 2014, the Company entered into a definitive agreement to acquire the outstanding equity interest of Contact At Once!, LLC (“Contact At Once!”), a software company with a cloud-based platform that instantly connects consumers with businesses through instant messaging, text messaging, chat, social media and video over the internet for consumer-to-business sales conversions, for approximately $70.0 million, which includes approximately $43.0 million in cash, approximately $22.0 million in shares of common stock and $5.0 million of potential earn-out consideration in cash or shares of common stock. The earn-out is contingent upon achieving certain targeted financial, strategic and integration objectives and milestones and is included as part of the purchase price. The acquisition enhances the Company’s network chat expertise and market growth across various verticals.
	The transaction will be accounted for under the purchase method of accounting and, accordingly, the operating results of Contact At Once! will be included in the Company’s consolidated results of operations from the date of acquisition. The Company is in process of finalizing all fair value and purchase accounting adjustments.

Description_of_Business_and_Ba1

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
SUMMARY OF OPERATIONS	'
	LivePerson, Inc. (the “Company” or “LivePerson”) was incorporated in the State of Delaware in November 1995 and the LivePerson service was introduced in November 1998. In April 2000, the Company completed an initial public offering and is currently traded on the Nasdaq Global Select Market and the Tel Aviv Stock Exchange. LivePerson is headquartered in New York City with offices in Amsterdam, Atlanta, London, Melbourne, San Francisco, Tokyo and Tel Aviv.
	LivePerson provides online engagement solutions offering a cloud-based platform which enables businesses to proactively connect with consumers through chat, voice and content delivery, across multiple channels and screens, including websites, social media, tablets and mobile devices. The Company’s engagements are driven by insights derived from a broad set of consumer and business data, including historical, behavioral, operational, and third party data. Each engagement is based on proprietary analytics and a real-time understanding of consumer needs and business objectives. The Company’s products, coupled with its domain knowledge and industry expertise, have been proven to maximize the effectiveness of the online channel — by increasing sales, as well as consumer satisfaction and loyalty ratings for its customers, while also enabling its customers to reduce consumer service costs.
	LivePerson monitors and analyzes valuable online consumer behavioral data on behalf of its customers. Spanning the breadth of an online visitor session, starting from an initial keyword search through actions on their customer’s website, and even into a shopping cart and an executed sale, this data enables the Company to develop unique insights into consumer behavior during specific transactions within a customer’s user base.
	The Company’s primary revenue source is from the sale of LivePerson services to businesses of all sizes. The Company also offers an online marketplace that connects independent service providers (“Experts”) who provide information and knowledge for a fee via real-time chat with individual consumers (“Users”).
BASIS OF PRESENTATION	'
	Basis of Presentation
	The accompanying condensed consolidated financial statements as of September 30, 2014 and for the three and nine months ended September 30, 2014 and 2013 are unaudited. In the opinion of management, the unaudited condensed consolidated financial statements have been prepared on the same basis as the annual financial statements and reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the consolidated financial position of LivePerson as of September 30, 2014, and the consolidated results of operations, comprehensive loss and cash flows for the interim periods ended September 30, 2014 and 2013. The financial data and other information disclosed in these notes to the condensed consolidated financial statements related to these periods are unaudited. The results of operations for any interim period are not necessarily indicative of the results of operations for any other future interim period or for a full fiscal year. The condensed consolidated balance sheet at December 31, 2013 has been derived from audited consolidated financial statements at that date.
	Certain information and note disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). These unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2013, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 14, 2014.
REVENUE RECOGNITION	'
	Revenue Recognition
	The majority of the Company’s revenue is generated from monthly service revenues and related professional services from the sale of the LivePerson services. Because the Company provides its application as a service, the Company follows the provisions of FASB Accounting Standards Codification (“ASC”) 605-10-S99, “Revenue Recognition” and ASC 605-25, “Revenue Recognition with Multiple-Element Arrangements.” The Company charges a monthly fee, which varies by type of service, the level of customer usage and website traffic, and in some cases, the number of orders placed via the Company’s online engagement solutions.
	For certain of the Company’s larger customers, the Company may provide call center labor through an arrangement with one or more of several qualified vendors. For most of these customers, the Company passes the fee it incurs with the labor provider and its fee for the hosted services through to its customers in the form of a fixed fee for each order placed via the Company’s online engagement solutions. For these Pay for Performance (“PFP”) arrangements, in accordance with ASC 605-45, “Principal Agent Considerations,” the Company records revenue for transactions in which it acts as an agent on a net basis, and revenue for transactions in which it acts as a principal on a gross basis.
	The Company also sells certain of the LivePerson services directly via Internet download.  These services are marketed as LiveEngage for small to medium-sized businesses (“SMBs”), and are paid for almost exclusively by credit card.  Credit card payments accelerate cash flow and reduce the Company’s collection risk, subject to the merchant bank's right to hold back cash pending settlement of the transactions.  Sales of LiveEngage may occur with or without the assistance of an online sales representative, rather than through face-to-face or telephone contact that is typically required for traditional direct sales.
	The Company recognizes monthly service revenue based upon the fee charged for the LivePerson services, provided that there is persuasive evidence of an arrangement, no significant Company obligations remain, collection of the resulting receivable is probable and the amount of fees to be paid is fixed or determinable. The Company’s service agreements typically have twelve month terms and, in some cases, are terminable or may terminate upon 30 to 90 days’ notice without penalty. When professional service fees add value to the customer on a standalone basis, the Company recognizes professional service fees upon completion and customer acceptance in accordance with FASB Accounting Standards Update 2009-13. This guidance establishes a selling price hierarchy for determining the selling price of a deliverable, which is based on: (a) vendor-specific objective evidence; (b) third-party evidence; or (c) best estimated selling price. If a professional services arrangement does not qualify for separate accounting, the Company recognizes the fees, and the related labor costs, ratably over the contracted period.
	For revenue generated from online transactions between Experts and Users, the Company recognizes revenue net of the Expert fees in accordance with ASC 605-45, “Principal Agent Considerations,” due primarily to the fact that the Expert is the primary obligor. Additionally, the Company performs as an agent without any risk of loss for collection, and is not involved in selecting the Expert or establishing the Expert’s fee. The Company collects a fee from the User and retains a portion of the fee, and then remits the balance to the Expert. Revenue from these transactions is recognized when there is persuasive evidence of an arrangement, no significant Company obligations remain, collection of the resulting receivable is probable and the amount of fees to be paid is fixed and determinable.
NET LOSS PER SHARE	'
	Net Loss Per Share
	The Company calculates earnings per share (“EPS”) in accordance with the provisions of ASC 260-10 and the guidance of SEC Staff Accounting Bulletin (“SAB”) No. 98. Under ASC 260-10, basic EPS excludes dilution for common stock equivalents and is computed by dividing net income or loss attributable to common shareholders by the weighted average number of common shares outstanding for the period. All options, warrants or other potentially dilutive instruments issued for nominal consideration are required to be included in the calculation of basic and diluted net income attributable to common stockholders. Diluted EPS is calculated using the treasury stock method and reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock and resulted in the issuance of common stock.
	Diluted net loss per common share for the three and nine months ended September 30, 2014 does not include the effect of options to purchase 11,127,640 shares of common stock as the effect of their inclusion is anti-dilutive. Diluted net loss per common share for the three and nine months ended September 30, 2013 does not include the effect of options to purchase 10,132,045 shares of common stock as the effect of their inclusion is anti-dilutive.
	A reconciliation of shares used in calculating basic and diluted earnings per share follows:
		Three Months Ended		Nine Months Ended
		September 30,		September 30,
		2014	2013	2014	2013
	Basic	53,868,124	54,046,161	54,238,536	54,898,974
	Effect of assumed exercised options	—	—	—	—
	Diluted	53,868,124	54,046,161	54,238,536	54,898,974
SEGMENT REPORTING	'
	Segment Information
	The Company accounts for its segment information in accordance with the provisions of ASC 280-10, “Segment Reporting.” ASC 280-10 establishes annual and interim reporting standards for operating segments of a company. ASC 280-10 requires disclosures of selected segment-related financial information about products, major customers, and geographic areas based on the Company’s internal accounting methods. The Company is organized into two operating segments for purposes of making operating decisions and assessing performance. The Business segment facilitates real-time online interactions – chat, voice and content delivery across multiple channels and screens for global corporations of all sizes. The Consumer segment facilitates online transactions between Experts and Users and sells its services to consumers. Both segments currently generate their revenue primarily in the United States. The chief operating decision makers evaluate performance, make operating decisions, and allocate resources based on the operating income of each segment. The reporting segments follow the same accounting polices used in the preparation of the Company’s condensed consolidated financial statements which are described in the summary of significant accounting policies. The Company allocates cost of revenue, sales and marketing and amortization of purchased intangibles to the segments, but it does not allocate product development expenses, general and administrative expenses and income tax expense because management does not use this information to measure performance of the operating segments.
GOODWILL AND INTANGIBLE ASSETS	'
	Amortization expense is calculated on a straight-line basis over the estimated useful life of the asset.
STOCK-BASED COMPENSATION	'
	Stock-Based Compensation
	The Company follows FASB ASC 718-10, “Stock Compensation,” which addresses the accounting for transactions in which an entity exchanges its equity instruments for goods or services, with a primary focus on transactions in which an entity obtains employee services in share-based payment transactions. ASC 718-10 requires measurement of the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award (with limited exceptions). Incremental compensation costs arising from subsequent modifications of awards after the grant date must be recognized.

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Reconciliation of Shares Used in Calculating Basic and Diluted Earnings Per Share	'
	A reconciliation of shares used in calculating basic and diluted earnings per share follows:
		Three Months Ended		Nine Months Ended
		September 30,		September 30,
		2014	2013	2014	2013
	Basic	53,868,124	54,046,161	54,238,536	54,898,974
	Effect of assumed exercised options	—	—	—	—
	Diluted	53,868,124	54,046,161	54,238,536	54,898,974

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Summary of Financial Information by Segment	'
	Summarized financial information by segment for the three months ended September 30, 2014, based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision makers, follows (amounts in thousands):
		Business		Consumer		Corporate			Consolidated
	Revenue:
	Hosted services – Business	$	43,702	$	—	$	—		$	43,702
	Hosted services – Consumer	—		3,992		—			3,992
	Professional services	5,093		—		—			5,093
	Total revenue	48,795		3,992		—			52,787
	Cost of revenue	12,679		625		—			13,304
	Sales and marketing	19,488		1,490		—			20,978
	Amortization of purchased intangibles	407		—		—			407
	Unallocated corporate expenses	—		—		18,499			18,499
	Operating income (loss)	$	16,221	$	1,877	$	(18,499	)	$	(401	)
	Summarized financial information by segment for the three months ended September 30, 2013, based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision makers, follows (amounts in thousands):
		Business		Consumer		Corporate			Consolidated
	Revenue:
	Hosted services – Business	$	38,007	$	—	$	—		$	38,007
	Hosted services – Consumer	—		3,828		—			3,828
	Professional services	3,357		—		—			3,357
	Total revenue	41,364		3,828		—			45,192
	Cost of revenue	10,014		583		—			10,597
	Sales and marketing	14,664		1,477		—			16,141
	Amortization of purchased intangibles	224		—		—			224
	Unallocated corporate expenses	—		—		19,531			19,531
	Operating income (loss)	$	16,462	$	1,768	$	(19,531	)	$	(1,301	)
	Summarized financial information by segment for the nine months ended September 30, 2014, based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision makers, follows (amounts in thousands):
		Business		Consumer		Corporate			Consolidated
	Revenue:
	Hosted services – Business	$	125,378	$	—	$	—		$	125,378
	Hosted services – Consumer	—		12,441		—			12,441
	Professional services	13,883		—		—			13,883
	Total revenue	139,261		12,441		—			151,702
	Cost of revenue	36,306		1,894		—			38,200
	Sales and marketing	55,203		4,246		—			59,449
	Amortization of purchased intangibles	803		—		—			803
	Unallocated corporate expenses	—		—		56,073			56,073
	Operating income (loss)	$	46,949	$	6,301	$	(56,073	)	$	(2,823	)
	Summarized financial information by segment for the nine months ended September 30, 2013, based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision makers, follows (amounts in thousands):
		Business		Consumer		Corporate			Consolidated
	Revenue:
	Hosted services – Business	$	110,785	$	—	$	—		$	110,785
	Hosted services – Consumer	—		11,223		—			11,223
	Professional services	8,909		—		—			8,909
	Total revenue	119,694		11,223		—			130,917
	Cost of revenue	29,524		1,818		—			31,342
	Sales and marketing	42,113		4,005		—			46,118
	Amortization of purchased intangibles	672		—		—			672
	Unallocated corporate expenses	—		—		56,672			56,672
	Operating income (loss)	$	47,385	$	5,400	$	(56,672	)	$	(3,887	)
Revenues Attributable to Domestic and Foreign Operations	'
	The following table presents the Company’s revenues attributable to domestic and foreign operations for the periods presented (amounts in thousands):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014			2013
	United States	$	34,409	$	28,947	$	99,273		$	86,553
	Other Americas (1)	2,936		2,353		7,259			6,145
	Total Americas	37,345		31,300		106,532			92,698
	EMEA (2)	11,049		9,600		32,618			25,572
	APAC (3)	4,393		4,292		12,552			12,647
	Total revenue	$	52,787	$	45,192	$	151,702		$	130,917
	(1) Canada, Latin America and South America
	(2) Europe, the Middle East and Africa (“EMEA”)
	(3) Asia-Pacific (“APAC”)
Long-Lived Assets by Geographic Region	'
	The following table presents the Company's long-lived assets by geographic region for the periods presented (amounts in thousands):
		September 30,		December 31,
		2014		2013
	United States	$	42,066	$	34,422
	Israel	19,700		22,580
	Australia	8,858		9,827
	Netherlands	7,687		3,540
	Other (1)	1,661		1,539
	Total long-lived assets	$	79,972	$	71,908

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes in Carrying Amount of Goodwill	'
	The changes in the carrying amount of goodwill for the nine months ended September 30, 2014 are as follows (amounts in thousands):
		Business		Consumer			Total
	Balance as of December 31, 2013	$	24,700	$	8,024		$	32,724
	Adjustments to goodwill:
	NexGraph acquisition	400		—			400
	Synchronite acquisition	2,659		—			2,659
	Balance as of September 30, 2014	$	27,759	$	8,024		$	35,783
	The changes in the carrying amount of goodwill for the year ended December 31, 2013 are as follows (amounts in thousands):
		Business		Consumer			Total
	Balance as of December 31, 2012	$	24,621	$	8,024		$	32,645
	Adjustments to goodwill:
	Adjustments to Engage acquisition	79		—			79
	Balance as of December 31, 2013	$	24,700	$	8,024		$	32,724
Summary of Intangible Assets	'
	Intangible assets are summarized as follows (see Note 8 and Note 10) (amounts in thousands):
		As of September 30, 2014
		Gross		Accumulated			Net Carrying Amount		Weighted
		Carrying		Amortization					Average
		Amount							Amortization
									Period
	Amortizing intangible assets:
	Technology	$	19,615	$	(10,320	)	$	9,295	4.1 years
	Customer relationships	5,308		(3,658		)	1,650		3.7 years
	Trade names	787		(730		)	57		2.8 years
	Non-compete agreements	646		(551		)	95		1.3 years
	Patents	3,290		(416		)	2,874		9.9 years
	Other	312		(263		)	49		3.0 years
	Total	$	29,958	$	(15,938	)	$	14,020
		As of December 31, 2013
		Gross		Accumulated			Net Carrying Amount		Weighted
		Carrying		Amortization					Average
		Amount							Amortization
									Period
	Amortizing intangible assets:
	Technology	$	18,533	$	(7,678	)	$	10,855	3.8 years
	Customer relationships	5,061		(3,148		)	1,913		3.5 years
	Trade names	725		(725		)	—		2.7 years
	Non-compete agreements	486		(486		)	—		1.2 years
	Patents	475		(189		)	286		11.0 years
	Other	285		(251		)	34		3.0 years
	Total	$	25,565	$	(12,477	)	$	13,088
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	'
	Estimated amortization expense for the next five years are as follows (amounts in thousands):
		Estimated Amortization Expense
	2014	$	1,135
	2015	4,267
	2016	3,805
	2017	2,205
	2018	485
	Thereafter	2,123
	Total	$	14,020

Property_and_Equipment_Tables

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Summary of Property and Equipment	'
	The following table presents the detail of property and equipment for the periods presented (amounts in thousands):
		September 30,			December 31,
		2014			2013
	Computer equipment and software	$	52,322		$	45,790
	Furniture, equipment and building improvements	9,078			7,906
		61,400			53,696
	Less: accumulated depreciation	(42,637		)	(36,078		)
	Total	$	18,763		$	17,618

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2014
Payables and Accruals [Abstract]	'
Accrued Liabilities	'
	The following table presents the detail of accrued liabilities for the periods presented (amounts in thousands):
		September 30,		December 31,
		2014		2013
	Payroll and other employee related costs	$	12,310	$	13,090
	Professional services and consulting and other vendor fees	9,427		6,769
	Sales commissions	2,733		1,778
	Contingent earnout (Note 8)	2,970		1,660
	Other	2,312		2,122
	Total	$	29,752	$	25,419

Acquisitions_Tables

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2014
Synchronite, LLC [Member]	'
Business Acquisition [Line Items]	'
Components of Intangible Assets	'
	The components of the intangible assets are as follows (amounts in thousands):
		Weighted		Amount
		Average Useful
		Life (Months)
	Technology	120		$	1,082
	Trade-name	48		62
	Customer relationships	84		247
	Non-compete agreements	36		60
				$	1,451
Look.io [Member]	'
Business Acquisition [Line Items]	'
Purchase Price Preliminary Allocation	'
	Management’s allocation of the purchase price in connection with the LookIO acquisition is as follows (amounts in thousands):
	Intangible assets (technology)	$	767
	Goodwill	2,405
		3,172
	Deferred tax liability	(288		)
	Total purchase price consideration	$	2,884
Engage Pty Ltd. [Member]	'
Business Acquisition [Line Items]	'
Purchase Price Preliminary Allocation	'
	Management’s preliminary allocation of the purchase price in connection with the Engage acquisition is as follows (amounts in thousands):
	Cash	$	386
	Accounts receivable	3,454
	Other current assets	57
	Property and equipment	432
	Other assets	104
	Intangible assets	3,600
	Goodwill	6,152
		14,185
	Liabilities assumed	(2,632		)
	Deferred tax liability	(962		)
	Total purchase price consideration	$	10,591
Components of Intangible Assets	'
	The components of the intangible assets listed in the above table are as follows (amounts in thousands):
		Weighted		Amount
		Average Useful
		Life (Months)
	Technology	36		$	768
	Trade-name	12		95
	Customer relationships	48		2,661
	Non-compete agreements	12		76
				$	3,600

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value, Assets Measured on Recurring Basis	'
	The Company's assets and liabilities that are measured at fair value on a recurring basis, by level, within the fair value hierarchy as of September 30, 2014 and December 31, 2013, are summarized as follows (amounts in thousands):
		September 30, 2014									December 31, 2013
		Level 1			Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Assets:
	Cash equivalents:
	Money market funds	$	12,608		$	—	$	—	$	12,608	$	13,674	$	—	$	—	$	13,674
	Total assets	$	12,608		$	—	$	—	$	12,608	$	13,674	$	—	$	—	$	13,674
	Liabilities:
	Contingent earn-out	$	—		$	—	$	2,970	$	2,970	$	—	$	—	$	1,660	$	1,660
	Total liabilities	$	—		$	—	$	2,970	$	2,970	$	—	$	—	$	1,660	$	1,660
Change in Fair Value of Level 3 Liabilities	'
	The changes in fair value of the Level 3 liabilities are as follows (amounts in thousands):
		Contingent Earn-Out
		30-Sep-14			31-Dec-13
	Balance, Beginning of Period	$	1,660		$	1,660
	Synchronite addition (see Note 8)	1,810			—
	Cash payment	(500		)	—
	Balance, End of Period	$	2,970		$	1,660

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Summary of Stock-Based Compensation Expense Related to Employee Stock Options	'
	The following table summarizes stock-based compensation expense related to employee stock options under ASC 718-10 included in Company’s statements of operations for the periods presented (amounts in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2014				2013				2014			2013
	Cost of revenue	$	365			$	635			$	1,209		$	1,557
	Sales and marketing expense	1,030				844				2,766			2,159
	Product development expense	1,171				1,241				2,783			2,922
	General and administrative expense	1,088				1,078				2,800			3,111
	Total stock based compensation included in costs and expenses	$	3,654			$	3,798			$	9,558		$	9,749
Weighted Average Assumptions of Fair Value Options Using Black-Scholes Option-Pricing Model	'
	The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
	Dividend yield	0.00%		0.00%		0.00%		0.00%
	Risk-free interest rate	1.70%		1.40%		1.5% - 1.7%		0.7% - 1.4%
	Expected life (in years)	5		5		5		5
	Historical volatility	50.90%		59.8% - 59.9%		50.9% - 53.7%		56.7% - 60.1%
Summary of Stock Option Activity and Weighted Average Exercise Prices	'
	A summary of the Company’s stock option activity and weighted average exercise prices follows:
		Stock Option Activity							Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
		Options			Weighted
					Average
					Exercise Price
	Balance outstanding at December 31, 2013	9,724,193			$	10.86
	Granted	3,289,700			10.63
	Exercised	(565,668	)		7.77
	Cancelled or expired	(1,320,585	)		12.8
	Balance outstanding at September 30, 2014	11,127,640			$	10.68			7.14		$	29,989
	Options vested and expected to vest at September 30, 2014	9,300,501			$	10.64			6.78		$	26,214
	Options exercisable at September 30, 2014	5,034,974			$	9.69			5.33		$	19,268
Summary of Status of Nonvested Shares	'
	A summary of the status of the Company’s nonvested shares as of December 31, 2013, and changes during the nine months ended September 30, 2014 is as follows:
		Options			Weighted
					Average Grant-
					Date Fair Value
	Nonvested Shares at December 31, 2013	5,633,701			$	6.9
	Granted	3,289,700			4.99
	Vested	(1,510,150	)		6.09
	Cancelled or expired	(1,320,585	)		6.49
	Nonvested Shares at September 30, 2014	6,092,666			$	5.65

Revenue_Recognition_Details

Revenue Recognition (Details)	9 Months Ended
	Sep. 30, 2014
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'
Typical service agreements	'12 months
Minimum [Member]	'
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'
Typical service agreements termination notice period	'30 days
Maximum [Member]	'
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'
Typical service agreements termination notice period	'90 days

Net_Loss_Per_Share_Narrative_D

Net Loss Per Share (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Effect of option to purchase share of common stock on diluted net income per share	11,127,640	10,132,045	11,127,640	10,132,045

Net_Loss_Per_Share_Reconciliat

Net Loss Per Share (Reconciliation of Shares Used in Calculating Basic and Diluted Earnings Per Share) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Basic	53,868,124	54,046,161	54,238,536	54,898,974
Effect of assumed exercised options	0	0	0	0
Diluted	53,868,124	54,046,161	54,238,536	54,898,974

Segment_Information_Narrative_

Segment Information (Narrative) (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2012
Segment Reporting [Abstract]	'	'
Number of operating segments	2	'
Customer Concentration Risk [Member] | Accounts Receivable [Member]	'	'
Concentration Risk [Line Items]	'	'
Concentration risk, percentage	22.00%	12.00%

Segment_Information_Summary_of

Segment Information (Summary of Financial Information by Segment) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Revenue	'		'		'		'
Hosted services – Business	$43,702		$38,007		$125,378		$110,785
Hosted services – Consumer	3,992		3,828		12,441		11,223
Professional services	5,093		3,357		13,883		8,909
Revenue	52,787		45,192		151,702		130,917
Cost of revenue	13,304	[1],[2]	10,597	[1],[2]	38,200	[1],[2]	31,342	[1],[2]
Sales and marketing	20,978	[1],[2]	16,141	[1],[2]	59,449	[1],[2]	46,118	[1],[2]
Amortization of purchased intangibles	407		224		803		672
Unallocated corporate expenses	18,499		19,531		56,073		56,672
Operating income (loss)	-401		-1,301		-2,823		-3,887
Business [Member]	'		'		'		'
Revenue	'		'		'		'
Hosted services – Business	43,702		38,007		125,378		110,785
Professional services	5,093		3,357		13,883		8,909
Revenue	48,795		41,364		139,261		119,694
Cost of revenue	12,679		10,014		36,306		29,524
Sales and marketing	19,488		14,664		55,203		42,113
Amortization of purchased intangibles	407		224		803		672
Operating income (loss)	16,221		16,462		46,949		47,385
Consumer [Member]	'		'		'		'
Revenue	'		'		'		'
Hosted services – Consumer	3,992		3,828		12,441		11,223
Revenue	3,992		3,828		12,441		11,223
Cost of revenue	625		583		1,894		1,818
Sales and marketing	1,490		1,477		4,246		4,005
Operating income (loss)	1,877		1,768		6,301		5,400
Corporate [Member]	'		'		'		'
Revenue	'		'		'		'
Unallocated corporate expenses	18,499		19,531		56,073		56,672
Operating income (loss)	($18,499)		($19,531)		($56,073)		($56,672)
[1]	Amounts include stock compensation expense as follows: Cost of revenue $365 and $635 for the three months ended September 30, 2014 and 2013, respectively and $1209 and $1557 for the nine months ended September 30, 2014 and 2013, respectively, Sales and marketing $1030 and $844 for the three months ended September 30, 2014 and 2013, respectively and $2,766 and $2,159 for the nine months ended September 30, 2014 and 2013, respectively, Product development $1,171 and $1,241 for the three months ended September 30, 2014 and 2013, respectively and $2,783 and $2,922 for the nine months ended September 30, 2014 and 2013, respectively, and General and administrative $1,088 and $1,078 for the three months ended September 30, 2014 and 2013, respectively and $2,800 and $3,111 for the nine months ended September 30, 2014 and 2013, respectively.
[2]	Amounts include depreciation expense as follows: Cost of revenue $1,732 and $1,445 for the three months ended September 30, 2014 and 2013, respectively and $4,776 and $4,565 for the nine months ended September 30, 2014 and 2013, respectively, Sales and marketing $195 and $23 for the three months ended September 30, 2014 and 2013, respectively and $603 and $68 for the nine months ended September 30, 2014 and 2013, respectively, Product development $180 and $166 for the three months ended September 30, 2014 and 2013, respectively and $529 and $526 for the nine months ended September 30, 2014 and 2013, respectively, and General and administrative $237 and $368 for the three months ended September 30, 2014 and 2013, respectively and $651 and $891 for the nine months ended September 30, 2014 and 2013, respectively.

Segment_Information_Revenues_A

Segment Information (Revenues Attributable to Domestic and Foreign Operations) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	$52,787		$45,192		$151,702		$130,917
United States [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	34,409		28,947		99,273		86,553
Other Americas [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	2,936	[1]	2,353	[1]	7,259	[1]	6,145	[1]
Americas [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	37,345		31,300		106,532		92,698
EMEA [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	11,049	[2]	9,600	[2]	32,618	[2]	25,572	[2]
APAC [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	$4,393	[3]	$4,292	[3]	$12,552	[3]	$12,647	[3]
[1]	Canada, Latin America and South America
[2]	Europe, the Middle East and Africa (“EMEA”)
[3]	Asia-Pacific (“APAC”)

Segment_Information_LongLived_

Segment Information (Long-Lived Assets by Geographic Region) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Segment Reporting Information [Line Items]	'	'
Total long-lived assets	$79,972	$71,908
United States [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total long-lived assets	42,066	34,422
Israel [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total long-lived assets	19,700	22,580
Australia [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total long-lived assets	8,858	9,827
Netherlands [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total long-lived assets	7,687	3,540
United Kingdom [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total long-lived assets	$1,661	$1,539

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'	'
Aggregate amortization expense for intangible assets	$1,300	$700	$3,461	$1,575

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets (Changes in Carrying Amount of Goodwill) (Details) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2012

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2012

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2012

Sep. 30, 2014

Mar. 31, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Nov. 09, 2012

Dec. 31, 2013

In Thousands, unless otherwise specified

Business [Member]

Business [Member]

Business [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

NexGraph, LLC [Member]

NexGraph, LLC [Member]

NexGraph, LLC [Member]

Synchronite, LLC [Member]

Synchronite, LLC [Member]

Engage Pty Ltd. [Member]

Engage Pty Ltd. [Member]

Engage Pty Ltd. [Member]

Business [Member]

Business [Member]

Business [Member]

Goodwill [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

$35,783

$32,724

$32,645

$27,759

$24,700

$24,621

$8,024

$8,024

$8,024

'

$400

'

'

'

'

$6,152

'

Goodwill acquisitions

'

'

'

'

'

'

'

'

'

400

'

400

2,659

2,659

79

'

79

Ending Balance

$35,783

$32,724

$32,645

$27,759

$24,700

$24,621

$8,024

$8,024

$8,024

'

$400

'

$2,700

'

'

$6,152

'

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets (Summary of Intangible Assets) (Details) (USD $)	9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'
Gross Carrying Amount	$29,958	$25,565	'
Accumulated Amortization	-15,938	'	-12,477
Intangibles, net	14,020	'	13,088
Technology [Member]	'	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'
Gross Carrying Amount	19,615	18,533	'
Accumulated Amortization	-10,320	'	-7,678
Intangibles, net	9,295	'	10,855
Weighted Average Amortization Period	'4 years 1 month 18 days	'	'3 years 9 months 18 days
Customer relationships [Member]	'	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'
Gross Carrying Amount	5,308	5,061	'
Accumulated Amortization	-3,658	'	-3,148
Intangibles, net	1,650	'	1,913
Weighted Average Amortization Period	'3 years 8 months	'	'3 years 6 months
Trade names [Member]	'	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'
Gross Carrying Amount	787	725	'
Accumulated Amortization	-730	'	-725
Intangibles, net	57	'	0
Weighted Average Amortization Period	'2 years 9 months 12 days	'	'2 years 8 months 12 days
Non-compete agreements [Member]	'	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'
Gross Carrying Amount	646	486	'
Accumulated Amortization	-551	'	-486
Intangibles, net	95	'	0
Weighted Average Amortization Period	'1 year 3 months 12 days	'	'1 year 2 months 12 days
Patents [Member]	'	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'
Gross Carrying Amount	3,290	475	'
Accumulated Amortization	-416	'	-189
Intangibles, net	2,874	'	286
Weighted Average Amortization Period	'9 years 11 months	'	'11 years
Other [Member]	'	'	'
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'
Gross Carrying Amount	312	285	'
Accumulated Amortization	-263	'	-251
Intangibles, net	$49	'	$34
Weighted Average Amortization Period	'3 years	'	'3 years

Goodwill_and_Intangible_Assets5

Goodwill and Intangible Assets (Future Amortization Expense) (Details) (USD $)	Sep. 30, 2014
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'
2014	$1,135
2015	4,267
2016	3,805
2017	2,205
2018	485
Thereafter	2,123
Total	$14,020

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Property plant and equipment gross	$61,400	$53,696
Less: accumulated depreciation	-42,637	-36,078
Total	18,763	17,618
Computer Equipment And Software [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property plant and equipment gross	52,322	45,790
Furniture, Equipment and Building Improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property plant and equipment gross	$9,078	$7,906

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]	'	'
Payroll and other employee related costs	$12,310	$13,090
Professional services and consulting and other vendor fees	9,427	6,769
Sales commissions	2,733	1,778
Contingent earnout (Note 8)	2,970	1,660
Other	2,312	2,122
Total	$29,752	$25,419

Acquisitions_Narrative_Details

Acquisitions (Narrative) (Details) (USD $)

9 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

9 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

31-May-12

Jun. 13, 2012

Sep. 30, 2014

Jun. 30, 2012

Nov. 09, 2012

Sep. 30, 2014

Dec. 31, 2012

Mar. 31, 2014

Jun. 02, 2014

Sep. 30, 2014

Amadesa Ltd. [Member]

Look.io [Member]

Look.io [Member]

Look.io [Member]

Engage Pty Ltd. [Member]

Engage Pty Ltd. [Member]

Engage Pty Ltd. [Member]

NexGraph, LLC [Member]

Synchronite, LLC [Member]

Synchronite, LLC [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business acquisition, acquisition date

'

'

'

'

31-May-12

13-Jun-12

'

'

9-Nov-12

'

'

1-Mar-14

2-Jun-14

'

Acquired Intangible Assets Amount

'

'

'

'

$10,300,000

'

'

'

'

'

'

$500,000

'

'

Acquired intangible asset, aggregate cash consideration

'

'

'

'

'

2,884,000

'

'

10,591,000

'

'

'

4,100,000

'

Intangible assets

2,800,000

'

'

'

500,000

767,000

'

'

3,600,000

'

'

100,000

1,451,000

1,450,000

Business acquisition, shares of common stock issued

'

'

'

'

'

109,517

'

'

'

'

'

'

'

'

Cash payment

2,300,000

0

'

'

'

900,000

'

'

'

'

'

'

'

'

Acquisition costs incurred to acquire entity

'

'

'

'

'

'

'

200,000

'

'

500,000

'

'

400,000

Goodwill

35,783,000

'

32,724,000

32,645,000

'

2,405,000

'

'

6,152,000

'

'

400,000

'

2,700,000

Business acquisition, value of shares of common stock issued

'

'

'

'

'

2,000,000

'

'

'

'

'

'

'

'

Potential shares of common stock in addition to purchase price

'

'

'

'

'

30,422

25,961

'

'

'

'

'

'

'

Potential shares of common stock, value

'

'

'

'

'

600,000

'

'

'

'

'

'

'

'

Weighted average shares outstanding used in basic and diluted net income per share as of the acquisition date

'

'

'

'

'

109,517

'

'

'

'

'

'

'

'

Assets acquired liabilities assumed, net

'

'

'

'

'

'

'

'

800,000

'

'

'

45,000

'

Potential earn-out consideration

'

'

'

'

'

'

'

'

1,600,000

'

'

'

1,800,000

'

Payment of a portion of potential earn-out consideration amount

'

'

'

'

'

'

'

'

'

$500,000

'

'

'

'

Acquisitions_Purchase_Price_Pr

Acquisitions (Purchase Price Preliminary Allocation) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Jun. 02, 2014	Jun. 13, 2012	Nov. 09, 2012
In Thousands, unless otherwise specified				Synchronite, LLC [Member]	Synchronite, LLC [Member]	Look.io [Member]	Engage Pty Ltd. [Member]
Business Acquisition [Line Items]	'	'	'	'	'	'	'
Cash	'	'	'	'	'	'	$386
Accounts receivable	'	'	'	'	'	'	3,454
Other current assets	'	'	'	'	'	'	57
Property and equipment	'	'	'	'	'	'	432
Other assets	'	'	'	'	'	'	104
Intangible assets	2,800	'	'	1,450	1,451	767	3,600
Goodwill	35,783	32,724	32,645	2,700	'	2,405	6,152
Total assets acquired	'	'	'	'	'	3,172	14,185
Liabilities assumed	'	'	'	'	'	'	-2,632
Deferred tax liability	'	'	'	'	'	-288	-962
Total purchase price consideration	'	'	'	'	$4,100	$2,884	$10,591

Acquisitions_Components_of_Int

Acquisitions (Components of Intangible Assets) (Details) (USD $)

Sep. 30, 2014

Jun. 13, 2012

Sep. 30, 2014

Sep. 30, 2014

Jun. 02, 2014

Nov. 09, 2012

Sep. 30, 2014

Dec. 31, 2013

Jun. 02, 2014

Nov. 09, 2012

Sep. 30, 2014

Dec. 31, 2013

Jun. 02, 2014

Nov. 09, 2012

Jun. 02, 2014

Nov. 09, 2012

Sep. 30, 2014

Dec. 31, 2013

Jun. 02, 2014

Nov. 09, 2012

In Thousands, except Share data, unless otherwise specified

Business Acquisition [Member]

Business Acquisition [Member]

Synchronite, LLC [Member]

Synchronite, LLC [Member]

Engage Pty Ltd. [Member]

Technology [Member]

Technology [Member]

Technology [Member]

Technology [Member]

Trade Names [Member]

Trade Names [Member]

Trade Names [Member]

Trade Names [Member]

Customer Relationships [Member]

Customer Relationships [Member]

Non-compete Agreements [Member]

Non-compete Agreements [Member]

Non-compete Agreements [Member]

Non-compete Agreements [Member]

Synchronite, LLC [Member]

Engage Pty Ltd. [Member]

Synchronite, LLC [Member]

Engage Pty Ltd. [Member]

Synchronite, LLC [Member]

Engage Pty Ltd. [Member]

Synchronite, LLC [Member]

Engage Pty Ltd. [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Potential Shares Of Common Stock In Addition To Purchase Price

'

30,422

25,961

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted Average Amortization Period

'

'

'

'

'

'

'4 years 1 month 18 days

'3 years 9 months 18 days

'120 months

'36 months

'2 years 9 months 12 days

'2 years 8 months 12 days

'48 months

'12 months

'84 months

'48 months

'1 year 3 months 12 days

'1 year 2 months 12 days

'36 months

'12 months

Intangible assets

$2,800

$767

'

$1,450

$1,451

$3,600

'

'

$1,082

$768

'

'

$62

$95

$247

$2,661

'

'

$60

$76

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (Recurring [Member], USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

In Thousands, unless otherwise specified

Level 1 [Member]

Level 1 [Member]

Level 3 [Member]

Level 3 [Member]

Total [Member]

Total [Member]

Money Market Funds [Member]

Money Market Funds [Member]

Money Market Funds [Member]

Money Market Funds [Member]

Contingent Earn-Out [Member]

Contingent Earn-Out [Member]

Contingent Earn-Out [Member]

Contingent Earn-Out [Member]

Engage [Member]

Engage [Member]

Synchronite, LLC [Member]

Level 1 [Member]

Level 1 [Member]

Total [Member]

Total [Member]

Level 3 [Member]

Level 3 [Member]

Total [Member]

Total [Member]

Contingent Earn-Out [Member]

Contingent Earn-Out [Member]

Contingent Earn-Out [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Assets, Fair Value Disclosure

$12,608

$13,674

'

'

$12,608

$13,674

$12,608

$13,674

$12,608

$13,674

'

'

'

'

'

'

'

Liabilities, Fair Value Disclosure

'

'

2,970

1,660

2,970

1,660

'

'

'

'

2,970

1,660

2,970

1,660

1,200

1,700

'

Change in contingent consideration

'

'

$1,810

$0

'

'

'

'

'

'

'

'

'

'

'

'

$1,800

Fair_Value_Measurements_Level_

Fair Value Measurements Level 3 Liabilities (Details) (Recurring [Member], Level 3 [Member], USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Recurring [Member] | Level 3 [Member]	'	'
Business Combination, Contingent Consideration Arrangements, Change In Contingent Consideration Liability [Roll Forward]	'	'
Balance, Beginning of Period	$1,660	$1,660
Synchronite addition	1,810	0
Cash payment	-500	0
Balance, End of Period	$2,970	$1,660

Investments_Details

Investments (Details) (USD $)	1 Months Ended	9 Months Ended
	Feb. 28, 2014	Sep. 30, 2014	Sep. 30, 2013
Investments, All Other Investments [Abstract]	'	'	'
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	'	$2,800,000	'
Cost-method investment amount	$3,500,000	$3,451,000	$0

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Commitments and Contingencies [Line Items]	'	'	'	'
Rental expense for operating leases	$2,300,000	$2,200,000	$6,900,000	$6,900,000
Defined benefit plan employer matching contribution on first five percent of employee compensation	'	'	50.00%	'
Defined benefit plan employer contribution limit	'	'	6,000	'
Defined benefit plan employer contribution vesting period	'	'	'5 years	'
Maximum [Member]	'	'	'	'
Commitments and Contingencies [Line Items]	'	'	'	'
Percentage of employees' eligible compensation for employer matching contribution	'	'	5.00%	'
Salaries And Related Expenses [Member]	'	'	'	'
Commitments and Contingencies [Line Items]	'	'	'	'
Defined benefit plan employer contribution	$200,000	$200,000	$800,000	$700,000

Stockholders_Equity_Narrative_

Stockholders' Equity (Narrative) (Details) (USD $)

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 30, 2010

Sep. 30, 2014

Sep. 30, 2014

Jul. 23, 2014

Mar. 13, 2014

Dec. 10, 2012

Incentive Stock Option [Member]

1998 Plan [Member]

2000 Plan [Member]

1998 and 2000 Plan [Member]

2009 Plan [Member]

2010 Employee Stock Purchase Plan [Member]

2010 Employee Stock Purchase Plan [Member]

2009 Plan [Member]

2012 Stock Repurchase Program [Member]

2012 Stock Repurchase Program [Member]

2012 Stock Repurchase Program [Member]

2012 Stock Repurchase Program [Member]

Incentive Stock Option [Member]

Incentive Stock Option [Member]

Incentive Stock Option [Member]

Incentive Stock Option [Member]

Incentive Stock Option [Member]

Maximum [Member]

Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, shares authorized

100,000,000

'

100,000,000

'

100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, shares issued (in shares)

54,584,170

'

54,584,170

'

54,484,760

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, shares outstanding (in shares)

54,584,170

'

54,584,170

'

54,484,760

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, par value (in dollars per share)

$0.00

'

$0.00

'

$0.00

'

'

'

'

'

'

'

'

'

'

'

'

Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, shares authorized

5,000,000

'

5,000,000

'

5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, shares issued (in shares)

0

'

0

'

0

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, shares outstanding (in shares)

0

'

0

'

0

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, par value (in dollars per share)

$0.00

'

$0.00

'

$0.00

'

'

'

'

'

'

'

'

'

'

'

'

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock repurchase program, authorized amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$50,000,000

$40,000,000

$30,000,000

Stock repurchased during period, shares

'

'

'

'

'

'

'

'

'

'

'

'

'

1,195,185

'

'

'

Treasury Stock, Shares

544,396

'

544,396

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock repurchase program, remaining authorized repurchase amount

'

'

'

'

'

'

'

'

'

'

'

'

'

10,300,000

'

'

'

Weighted average fair value of stock options granted

$4.57

$4.82

$4.99

$5.25

'

'

'

'

'

'

'

'

'

'

'

'

'

Dividend yield

0.00%

0.00%

0.00%

0.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares of common stock available for issuance

'

'

'

'

'

'

5,850,000

'

10,000,000

13,995,000

582,000

1,000,000

23,817,744

'

'

'

'

Increase in number of shares of common stock available for issuance

'

'

'

'

'

'

'

4,150,000

'

6,000,000

'

'

4,250,000

'

'

'

'

Stock option term

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total value of stock options exercised

'

'

2,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized compensation cost related to nonvested share-based compensation arrangements

'

'

'

'

'

$30,300,000

'

'

'

'

'

'

'

'

'

'

'

Weighted average recognition period of unrecognized compensation cost

'

'

'

'

'

'2 years 9 months

'

'

'

'

'

'

'

'

'

'

'

Stockholders_Equity_Summary_of

Stockholders' Equity (Summary of Stock-Based Compensation Expense Related to Employee Stock Options) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$3,654	$3,798	$9,558	$9,749
Cost of revenue [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	365	635	1,209	1,557
Sales and marketing expense [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	1,030	844	2,766	2,159
Product development expense [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	1,171	1,241	2,783	2,922
General and administrative expense [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$1,088	$1,078	$2,800	$3,111

Stockholders_Equity_Weighted_A

Stockholders' Equity (Weighted Average Assumptions of Fair Value Options Using Black-Scholes Option-Pricing Model) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Dividend yield	0.00%	0.00%	0.00%	0.00%
Risk-free interest rate	1.70%	1.40%	'	'
Expected life (in years)	'5 years	'5 years	'5 years	'5 years
Historical volatility	50.90%	'	'	'
Minimum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	'	'	1.50%	0.70%
Historical volatility	'	59.80%	50.90%	56.70%
Maximum [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk-free interest rate	'	'	1.70%	1.40%
Historical volatility	'	59.90%	53.70%	60.10%

Stockholders_Equity_Summary_of1

Stockholders' Equity (Summary of Stock Option Activity and Weighted Average Exercise Prices) (Details) (USD $)	9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014
Options	'
Options outstanding at December 31, 2013	9,724,193
Options granted	3,289,700
Options exercised	-565,668
Options cancelled	-1,320,585
Options outstanding at September 30, 2014	11,127,640
Options vested and expected to vest at September 30, 2014	9,300,501
Options exercisable at September 30, 2014	5,034,974
Weighted Average Exercise Price	'
Options outstanding at December 31, 2013	$10.86
Options granted	$10.63
Options exercised	$7.77
Options cancelled	$12.80
Options outstanding at September 30, 2014	$10.68
Options vested and expected to vest at September 30, 2014	$10.64
Legal Matters	'
	Legal Matters
	The Company routinely assesses all of its litigation and threatened litigation as to the probability of ultimately incurring a liability, and records its best estimate of the ultimate loss in situations where the Company assesses the likelihood of loss as probable.
	From time to time, the Company is involved in or subject to legal, administrative and regulatory proceedings, claims, demands and investigations arising in the ordinary course of business, including direct claims brought by or against the Company with respect to intellectual property, contracts, employment and other matters, as well as claims brought against the Company’s customers for whom the Company has a contractual indemnification obligation. The Company accrues for a liability when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Significant judgment is required in both the determination of probability and the determination as to whether a loss is reasonably estimable. In addition, in the event the Company determines that a loss is not probable, but is reasonably possible, and it becomes possible to develop what the Company believes to be a reasonable range of possible loss, then the Company will include disclosures related to such matter as appropriate and in compliance with ASC 450. The accruals or estimates, if any, resulting from the foregoing analysis, are reviewed at least quarterly and adjusted to reflect the impact of negotiations, settlements, rulings, advice of legal counsel and other information and events pertaining to a particular matter. To the extent there is a reasonable possibility that the losses could exceed the amounts already accrued, the Company will, as applicable, adjust the accrual in the period the determination is made, disclose an estimate of the additional loss or range of loss, indicate that the estimate is immaterial with respect to its financial statements as a whole or, if the amount of such adjustment cannot be reasonably estimated, disclose that an estimate cannot be made.
Options exercisable at September 30, 2014	$9.69
Weighted Average Remaining Contractual Term (in years)	'
Options outstanding at September 30, 2014	'7 years 1 month 21 days
Options vested and expected to vest at September 30, 2014	'6 years 9 months 11 days
Options exercisable at September 30, 2014	'5 years 3 months 29 days
Aggregate Intrinsic Value	'
Options outstanding at September 30, 2014	$29,989
Options vested and expected to vest at September 30, 2014	26,214
Options exercisable at September 30, 2014	$19,268

Stockholders_Equity_Summary_of2

Stockholders' Equity (Summary of Status of Nonvested Shares) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Shares	'
Nonvested Shares at December 31, 2013	5,633,701
Granted	3,289,700
Vested	-1,510,150
Cancelled or expired	-1,320,585
Nonvested Shares at September 30, 2014	6,092,666
Weighted Average Grant-Date Fair Value	'
Nonvested Shares at December 31, 2013	$6.90
Granted	$4.99
Vested	$6.09
Cancelled or expired	$6.49
Nonvested Shares at September 30, 2014	$5.65

Subsequent_Event_Details

Subsequent Event (Details) (USD $)	9 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Nov. 05, 2014	Nov. 05, 2014
			Contact At Once! [Member]	Contact At Once! [Member]
			Subsequent Event [Member]	Subsequent Event [Member]
Subsequent Event [Line Items]	'	'	'	'
Business acquisition, acquisition date	'	'	5-Nov-14	'
Total purchase price consideration	'	'	'	$70,000,000
Cash payment	2,300,000	0	43,000,000	'
Business acquisition, value of shares of common stock issued	'	'	22,000,000	'
Potential earn-out consideration	'	'	'	$5,000,000