Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 174,780	$ 93,192	$ 126,521
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	71,537	52,793	36,117
Deferred income taxes	(5,126)	(19,745)	16,246
Stock-based compensation expense	75,206	49,045	32,114
Deferred compensation plan	(15,782)	95,046	177
Amortization of deferred debt issuance costs	7,291	5,955	985
Change in fair value of derivative	(27,083)	(9,770)	(347)
Foreign currency remeasurement loss (gain)	6,000	64	(24,502)
Other non-cash items, net	2,593	5,338	134
Changes in assets and liabilities, net of effect from acquisitions:
Accounts receivable	(60,938)	(35,519)	12,388
Prepaid and other assets	14,053	14,260	11,705
Accounts payable, accruals, and other liabilities	29,181	47,957	51,185
Deferred revenues	2,292	5,340	(565)
Income taxes payable, net of prepaid income taxes	320	(15,932)	(3,818)
Net cash provided by operating activities	274,324	288,024	258,340
Cash flows from investing activities:
Purchases of property and equipment and investment in capitalized software	(18,546)	(17,539)	(16,447)
Proceeds from sale of aircraft	2,380	0	0
Acquisitions, net of cash acquired	(743,007)	(1,034,983)	(93,032)
Other investing activities	(10,954)	(4,081)	(7,854)
Net cash used in investing activities	(770,127)	(1,056,603)	(117,333)
Cash flows from financing activities:
Proceeds from credit facilities	833,292	745,310	550,875
Payments of credit facilities	(487,694)	(991,310)	(538,625)
Proceeds from convertible senior notes, net of discounts and commissions	0	1,233,377	0
Payments of debt issuance costs	0	(5,643)	(432)
Purchase of capped call options	0	(51,605)	0
Settlement of convertible senior notes	(1,998)	0	0
Proceeds from term loans	0	199,505	125,000
Repayments from term loans	(5,000)	0	(125,000)
Payments of acquisition debt and other consideration	(8,460)	(2,371)	(3,425)
Proceeds from issuance of common stock	0	0	58,349
Payments of Class B Common Stock follow-on offering expenses	0	0	1,373
Payments of dividends	(34,493)	(33,396)	(422,646)
Proceeds from stock purchases under employee stock purchase plan	10,335	3,846	0
Proceeds from exercise of stock options	8,338	5,605	9,128
Payments for shares acquired including shares withheld for taxes	(43,561)	(120,539)	(83,975)
Repurchase of Class B Common Stock under approved program	(28,250)	0	0
Other financing activities	525	(197)	(189)
Net cash provided by (used in) financing activities	243,034	982,582	(136,511)
Effect of exchange rate changes on cash and cash equivalents	(4,884)	(6,672)	(3,591)
(Decrease) increase in cash and cash equivalents	(257,653)	207,331	905
Cash and cash equivalents, beginning of year	329,337	122,006	121,101
Cash and cash equivalents, end of year	71,684	329,337	122,006
Supplemental information:
Cash paid for income taxes	29,478	40,203	28,986
Income tax refunds	3,588	9,372	3,863
Interest paid	26,581	4,631	8,012
Non-cash investing and financing activities:
Cost method investment, non-cash exchange	5,936	0	0
Shares issued related to acquisition	0	182,390	0
Contingent acquisition consideration	1,390	4,544	2,380
Deferred, non-contingent consideration, net	749	10,090	1,416
Term loan expenses included in Accruals and other current liabilities	0	45	0
Share-settled Executive Bonus Plan awards	21,925	20,953	0
Deferred compensation plan elective participant deferrals	6,580	2,619	3,530
Follow-On Offering
Cash flows from financing activities:
Proceeds from issuance of common stock	$ 0	$ 0	$ 295,802