Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating activities:
Net (loss) income	$ (7,246)	$ 3,704
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	14,229	7,175
Loss on asset disposal	436	434
Foreign currency transaction gain (loss)	27	(12)
Stock-based compensation expense	8,406	3,104
Deferred taxes	(2,851)	(944)
Change in operating assets and liabilities:
Accounts receivable, net	22,599	12,643
Prepaid expenses and other assets	(4,331)	(2,256)
Accounts payable, accrued expenses and other liabilities	3,755	8,406
Deferred revenue	(9,585)	(4,100)
Net cash provided by operating activities	25,439	28,154
Investing activities:
Purchase of property and equipment	(3,973)	(14,790)
Capitalized software development costs	(15,278)	(10,094)
Net purchases of short-term investments	(8,367)	(7,325)
Acquisition and acquisition-related consideration payments	(19,259)	(4,121)
Restricted cash	15	252
Net cash used in investing activities	(46,862)	(36,078)
Financing activities:
Proceeds from exercise of stock options	1,663	660
Excess tax benefits from stock-based compensation	2,514	0
Proceeds from follow-on public offering, net of expenses	0	24,846
Net cash provided by financing activities	4,177	25,506
Effect of exchange rate changes on cash and cash equivalents	(124)	12
Change in cash and cash equivalents	(17,370)	17,594
Cash and cash equivalents, beginning of period	144,544	146,407
Cash and cash equivalents, end of period	127,174	164,001
Supplemental cash flow information:
Income taxes paid	568	1,015
Supplemental disclosure of noncash investing activities:
Outstanding payments for purchase of property and equipment in accounts payable at period end	$ 322	$ 1,368