Income Taxes (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Components of loss before income taxes
Domestic									$ 8,237,000	$ 3,959,000	$ (683,000)
Foreign									(2,264,000)	(441,000)	(1,738,000)
(Loss) income before income tax provision	2,075,000	1,577,000	965,000	1,356,000	2,099,000	702,000	371,000	346,000	5,973,000	3,518,000	(2,421,000)
Current tax provision:
State									119,000	330,000	229,000
Foreign									492,000	(33,000)
Total current expense									611,000	297,000	229,000
Deferred tax provision:
Federal									737,000	458,000	282,000
State									273,000	40,000	23,000
Foreign									(610,000)	(315,000)
Total deferred expense									400,000	183,000	305,000
Total income tax provision	343,000	22,000	415,000	231,000	172,000	121,000	33,000	154,000	1,011,000	480,000	534,000
Reconciliation of income taxes related to the income (loss) from operations and the amount computed using Federal statutory income tax rate
Tax (benefit) provision computed at the federal statutory rate									2,090,000	1,231,000	(847,000)
Increase in fair value of warrants for redeemable convertible preferred stock											699,000
Foreign operating losses											174,000
Foreign tax rate differential									(3,000)	(127,000)
Tax benefit of exercised stock options and warrants									(1,423,000)	(9,996,000)	(3,375,000)
Research and development tax credits									51,000	(205,000)	(507,000)
Adjustment to prior year deferred and other									227,000	(1,439,000)	449,000
Change in valuation allowance									(1,008,000)	10,302,000	3,407,000
Taxable goodwill									737,000	499,000	305,000
State income taxes									340,000	215,000	229,000
Total income tax provision	343,000	22,000	415,000	231,000	172,000	121,000	33,000	154,000	1,011,000	480,000	534,000
Deferred tax assets:
Net operating losses	19,675,000				26,002,000				19,675,000	26,002,000
Unused research and development credits	3,450,000				3,318,000				3,450,000	3,318,000
Deferred revenue	885,000				743,000				885,000	743,000
Stock-based compensation	4,235,000				2,937,000				4,235,000	2,937,000
Accrued expenses	570,000				441,000				570,000	441,000
Deferred rent	149,000				198,000				149,000	198,000
Fixed assets	276,000				108,000				276,000	108,000
Acquisition-related expenses	68,000				61,000				68,000	61,000
Allowance for doubtful accounts	79,000				194,000				79,000	194,000
Alternative Minimum Tax credit available	34,000				34,000				34,000	34,000
Other	166,000				85,000				166,000	85,000
Less: valuation allowance	(25,930,000)				(29,048,000)				(25,930,000)	(29,048,000)
Deferred tax assets, gross	3,657,000				5,073,000				3,657,000	5,073,000
Deferred tax liabilities:
Intangible assets	(6,727,000)				(7,676,000)				(6,727,000)	(7,676,000)
Other	(22,000)				(102,000)				(22,000)	(102,000)
Net deferred tax liability	(3,092,000)				(2,705,000)				(3,092,000)	(2,705,000)
Decrease in valuation allowance									(3,100,000)
Net operating loss carryforwards resulting from tax deductions related to stock options awarded									41,000,000
Net operating loss carryforwards
Net operating loss carryforwards	85,700,000								85,700,000
Unrecognized tax benefits									0	0
Accruals for interest or penalties	0				0				0	0
Undistributed foreign earnings	1,800,000								1,800,000
Federal
Net operating loss carryforwards
Net operating loss carryforwards	44,700,000								44,700,000
Net operating loss carryforwards available to offset future taxable income					57,100,000					57,100,000
Net operating loss carryforwards available in prescribed increments in each future year through December 31, 2031	28,600,000								28,600,000
Federal | Research and development
Net operating loss carryforwards
Tax credit carryforward	$ 3,500,000								$ 3,500,000