Consolidated Statement of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 101,916	$ 68,745
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,280	16,664
Bad debt allowance	291	293
Deferred income taxes	(915)	5,284
Deferred compensation plan activity	1,855	1,633
Stock-based compensation expense	20,598	3,212
Amortization and write-off of deferred debt issuance costs	2,371	277
Change in fair value of derivative	(7,735)	4,174
Change in fair value of contingent consideration	0	(1,390)
Foreign currency remeasurement (gain) loss	(2,371)	3,538
Loss from investment accounted for using the equity method, net of tax	2,275	866
Changes in assets and liabilities, net of effect from acquisitions:
Accounts receivable	(4,665)	44,263
Prepaid and other assets	10,485	9,089
Accounts payable, accruals, and other liabilities	37,623	11,208
Deferred revenues	(4,756)	(29,500)
Income taxes payable, net of prepaid income taxes	(27,230)	(2,174)
Net cash provided by operating activities	149,022	136,182
Cash flows from investing activities:
Purchases of property and equipment and investment in capitalized software	(4,750)	(9,970)
Acquisitions, net of cash acquired of $36,847 and $2,064, respectively	(1,002,551)	(67,595)
Other investing activities	(700)	(1,414)
Net cash used in investing activities	(1,008,001)	(78,979)
Cash flows from financing activities:
Proceeds from credit facilities	581,233	164,375
Payments of credit facilities	(790,846)	(191,125)
Proceeds from convertible senior notes, net of discounts and commissions	1,233,377	0
Payments of debt issuance costs	(4,951)	0
Purchase of capped call options	(51,555)	0
Payments of financing leases	(101)	(93)
Payments of acquisition debt and other consideration	(544)	(1,091)
Payments of dividends	(16,591)	(15,901)
Payments for shares acquired including shares withheld for taxes	(87,836)	(69,307)
Proceeds from Common Stock Purchase Agreement	0	58,349
Proceeds from exercise of stock options	4,324	2,237
Net cash provided by (used in) financing activities	866,510	(52,556)
Effect of exchange rate changes on cash and cash equivalents	1,617	(232)
Increase in cash and cash equivalents	9,148	4,415
Cash and cash equivalents, beginning of year	122,006	121,101
Cash and cash equivalents, end of period	131,154	125,516
Supplemental information:
Cash paid for income taxes	25,109	7,180
Income tax refunds	5,895	298
Interest paid	1,871	3,162
Shares issued related to acquisition	182,390	0
Contingent acquisition consideration	4,991	1,706
Deferred, non-contingent consideration, net	9,593	1,069
Convertible senior notes expenses included in Accounts payable and Accruals and other current liabilities	692	0
Capped call options expenses included in Accounts payable and Accruals and other current liabilities	50	0
Share-settled Executive Bonus Plan awards	11,723	0
Voluntary deferred compensation plan contributions	$ 1,493	$ 1,798