CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income (loss)	$ 9,156	$ (1,683)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Stock-based compensation expense	5,663	7,256
Depreciation	15,019	14,980
Amortization of intangibles	13,412	12,954
Amortization of debt issuance costs and debt discount	1,217	1,151
Deferred income taxes	(1,568)	(181)
Change in fair value of acquisition-related contingent consideration	0	109
Other	(171)	(295)
Changes in assets and liabilities:
Accounts receivable	3,928	1,614
Prepaid expenses and other current assets	(3,798)	635
Income taxes receivable	(2,183)	(3,624)
Other assets	3,020	(862)
Accounts payable and accrued expenses	(3,257)	(2,844)
Accrued compensation	(15,668)	(15,558)
Other current and non-current liabilities	1,909	(2,996)
Deferred revenue	5,757	3,443
Net cash provided by operating activities	32,436	14,099
Cash flows from investing activities:
Purchases of property and equipment	(4,448)	(5,533)
Investment in capitalized software	(13,988)	(10,940)
Purchase of intangible assets	(2,556)	0
Net cash used in investing activities	(20,992)	(16,473)
Cash flows from financing activities:
Proceeds from credit facility borrowings	0	99,000
Repayment of credit facility borrowings	(2,450)	(2,450)
Payments for debt issuance costs	0	(1,000)
Proceeds from exercise of stock options	1,110	183
Finance lease liabilities paid	(1,119)	(631)
Tax payments for equity award issuances	(4,235)	(2,947)
Net cash (used in) provided by financing activities	(6,694)	92,155
Increase in cash and cash equivalents	4,750	89,781
Cash and cash equivalents, beginning of period	123,880	93,094
Cash and cash equivalents, end of period	128,630	182,875
Supplemental cash flow disclosure:
Income taxes paid, net	1,489	357
Interest paid	10,390	13,092
Non-cash transactions:
Accruals for purchases of property and equipment	7,050	1,606
Accruals for investment in capitalized software	9,103	1,440
Accruals for purchase of intangible assets	$ 1,125	$ 10,819