Consolidated statements of cash flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ 5,433	$ (9,434)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	7,525	5,084
Provision for bad debt	269	116
Stock-based compensation expense	650	14,037
Deferred income taxes	(283)	(3,679)
Other, net	(154)	34
Changes in assets and liabilities:
Accounts receivable	11,743	11,412
Prepaid expenses and other current assets	(2,927)	(3,850)
Other long-term assets	(278)	(2,567)
Accounts payable	335	955
Accrued compensation and benefits	73	(1,531)
Other accrued expenses and current liabilities	(4,496)	(2,331)
Deferred revenue	19,423	17,871
Net cash provided by operating activities	37,313	26,117
INVESTING ACTIVITIES:
Payments for acquisition of businesses, net of cash acquired	(7,028)	(6,437)
Capital expenditures	(3,130)	(2,335)
Payments for acquisition of developed technology	(2,738)	(2,120)
Other investing activities, net	38	(28)
Net cash used in investing activities	(12,858)	(10,920)
FINANCING ACTIVITIES:
Proceeds from issuance of Class A common stock in follow-on public offering, net of underwriters' discounts and commissions	135,572
Proceeds from the exercise of stock options	1,668	476
Payments for follow-on public offering and initial public offering costs	(468)	(869)
Payments for redemption of common stock	(119)	(611)
Principal payments on long-term debt	(76)	(5,248)
Payments on revolving commitment		(53,564)
Borrowings under revolving commitment		44,227
Other financing activities	(147)	(20)
Net cash provided by (used in) financing activities	136,430	(15,609)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(877)	962
Net increase in cash, cash equivalents and restricted cash	160,008	550
Cash, cash equivalents and restricted cash at beginning of year	39,578	17,139
Cash, cash equivalents and restricted cash at end of period	199,586	17,689
Supplemental disclosure of cash flow:
Interest paid	41	1,163
Income taxes paid	3,660	2,352
Supplemental disclosure of non-cash investing and financing activities:
Capital leases	1,010
Property and equipment in accounts payable and other accrued expenses and current liabilities	935	155
Follow-on public offering costs in accounts payable	88
Promissory notes issued and deferred payment obligations for acquisitions	$ 278	2,728
Issuance of common stock with put rights		2,345
Initial public offering costs in other long-term assets		1,522
Issuance of common stock in connection with acquisitions		$ 415