Consolidated statements of cash flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES:
Net income	$ 9,899	$ 23,604
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,468	7,525
Provision for bad debt	134	269
Amortization of debt discount and issuance costs	459	12
Stock-based compensation expense	3,292	650
Deferred income taxes	(703)	1,312
Other, net	(17)	(166)
Changes in assets and liabilities:
Accounts receivable	10,406	11,743
Prepaid expenses and other current assets	(4,952)	(3,454)
Other long-term assets	(2,300)	(276)
Accounts payable	(2,187)	335
Accrued compensation and benefits	(2,455)	73
Other accrued expenses and current liabilities	1,887	(4,511)
Operating lease right-of-use assets and liabilities, net	197
Deferred revenue	7,740	197
Net cash provided by operating activities	31,868	37,313
INVESTING ACTIVITIES:
Capital expenditures	(6,667)	(3,130)
Payments for acquisition of developed technology	(344)	(2,738)
Payments for acquisition of businesses, net of cash acquired	(709)	(7,028)
Other investing activities, net	16	38
Net cash used in investing activities	(7,704)	(12,858)
FINANCING ACTIVITIES:
Proceeds from issuance of convertible senior notes, net of underwriters' discount and commissions	223,101
Payments on revolving commitment	(127,941)
Borrowings under revolving commitment	96,991
Proceeds from the exercise of stock options	1,270	1,668
Payments for issuance costs of convertible senior notes	(1,018)
Payments for follow-on public offering and initial public offering costs		(468)
Proceeds from issuance of Class A common stock in follow-on public offering, net of underwriters' discounts and commissions		135,572
Other financing activities	(259)	(342)
Net cash provided by financing activities	192,144	136,430
Effect of exchange rate changes on cash, cash equivalents and restricted cash	187	(877)
Net increase in cash, cash equivalents and restricted cash	216,495	160,008
Cash, cash equivalents and restricted cash at beginning of year	35,685	39,578
Cash, cash equivalents and restricted cash at end of period	252,180	199,586
Supplemental disclosure of cash flow:
Interest paid	362	41
Income taxes paid	4,054	3,660
Supplemental disclosure of non-cash investing and financing activities:
Finance leases	566	1,010
Property and equipment in accounts payable	417	935
Convertible senior notes issuance costs in accounts payable	$ 216
Follow-on public offering costs in accounts payable		88
Promissory notes issued and deferred payment obligations for acquisitions		$ 278