Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net income	$ 158,189	$ 129,331	$ 84,734
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	96,706	78,862	69,086
Amortization of contract acquisition costs	983	590	1,002
Amortization of debt issuance costs	1,016	732	1,083
Imputed interest expense and fair value adjustments to contingent consideration	1,168	4,484	2,339
Provision for credit losses	(350)	494	1,711
(Gain) loss on disposal of assets	1,127	521	189
Loss on dissolution of subsidiary	0	19,905	0
Impairment losses	11,254	5,809	3,735
Deferred income taxes	831	(5,193)	(1,376)
Excess tax benefit from equity-based awards	(5,301)	(726)	(1,231)
Equity-based compensation expense	16,425	12,507	12,814
(Gain) loss on foreign currency derivatives	(213)	103	(140)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	40,156	(40,625)	29,608
Prepaids and other assets	18,407	57,597	27,413
Accounts payable and accrued expenses	(17,209)	76,726	97,268
Deferred revenue and other liabilities	(71,893)	(69,197)	(90,246)
Net cash provided by operating activities	251,296	271,920	237,989
Cash flows from investing activities
Proceeds from sale of long-live assets	93	20	382
Purchases of property, plant and equipment	(60,358)	(59,772)	(60,776)
Acquisitions, net of cash acquired of $18,638, $4,423 and $4,547, respectively	(481,718)	(52,675)	(102,457)
Net cash used in investing activities	(541,983)	(112,427)	(162,851)
Cash flows from financing activities
Net proceeds (borrowings) from line of credit	406,000	95,000	8,000
Payments on other debt	(6,626)	(8,619)	(11,855)
Payments of contingent consideration and hold back payments to acquisitions	(11,517)	(48,686)	(5,902)
Dividends paid to shareholders	(42,217)	(134,554)	(28,739)
Payments to noncontrolling interest	(10,984)	(10,801)	(4,950)
Capital contribution from noncontrolling interest	0	0	3,362
Tax payments related to issuance of restricted stock units	(11,397)	(4,521)	(5,471)
Payments of debt issuance costs	(3,614)	(45)	(1,819)
Net cash (used in) provided by financing activities	319,645	(112,226)	(47,374)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(7,291)	6,157	(410)
Increase (decrease) in cash, cash equivalents and restricted cash	21,667	53,424	27,354
Cash, cash equivalents and restricted cash, beginning of period	159,015	105,591	78,237
Cash, cash equivalents and restricted cash, end of period	180,682	159,015	105,591
Supplemental disclosures
Cash paid for interest	11,188	10,233	13,108
Cash paid for income taxes	71,392	47,761	36,316
Non-cash investing and financing activities
Acquisition of long lived assets through finance leases	912	1,852	3,731
Acquisition of equipment through increase in accounts payable, net	$ (2,243)	$ 347	$ 881