Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows - operating activities:
Net income including noncontrolling interests		$ 383,701	$ 132,943	$ 325,140
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		48,347	46,721	43,945
Amortization of identifiable intangible assets		64,089	59,950	48,142
Provision for credit losses		8,041	3,269	2,628
Deferred income taxes		9,517	(36,354)	1,701
Gain on sale or disposal of property, plant and equipment		(782)	(122)	(3,981)
Excess tax benefits from share-based compensation		(828)	(191)	(984)
Equity loss (income) from unconsolidated entities		1,170	(14)	2,990
Non-cash expense for amortization of debt issuance costs		960	998	1,186
Non-cash expense from contingent consideration arrangements		1,810	649	1,373
Non-cash expense for impairment of goodwill, identifiable intangible assets, and other long- lived assets		0	232,750	0
Non-cash share-based compensation expense		11,107	11,151	11,386
Distributions from unconsolidated entities		44	0	1,074
Changes in operating assets and liabilities, excluding the effect of businesses acquired:
(Increase) decrease in accounts receivable		(246,856)	139,377	(135,954)
(Increase) decrease in inventories		(116)	(12,709)	4,345
(Increase) decrease in contract assets		(50,648)	7,829	(10,111)
Increase (decrease) in accounts payable		54,849	(9,022)	(33,971)
Increase in contract liabilities		44,713	85,142	51,310
Increase in accrued payroll and benefits and other accrued expenses and liabilities		46,573	113,835	49,551
Changes in other assets and liabilities, net		(56,874)	30,164	(4,070)
Net cash provided by operating activities		318,817	806,366	355,700
Cash flows - investing activities:
Payments for acquisitions of businesses, net of cash acquired		(118,239)	(50,357)	(300,980)
Proceeds from sale or disposal of property, plant and equipment		2,754	3,463	5,487
Purchases of property, plant and equipment		(36,192)	(47,969)	(48,432)
Investments in and advances to unconsolidated entities		(1,595)	0	(2,252)
Distributions from unconsolidated entities		196	0	838
Net cash used in investing activities		(153,076)	(94,863)	(345,339)
Cash flows - financing activities:
Proceeds from revolving credit facility		0	200,000	50,000
Repayments of revolving credit facility		0	(250,000)	(25,000)
Proceeds from long-term debt		0	300,000	0
Repayments of long-term debt and debt issuance costs		(13,875)	(286,987)	(15,198)
Repayments of finance lease liabilities		(4,189)	(4,470)	(4,571)
Dividends paid to stockholders		(28,163)	(17,674)	(17,950)
Repurchases of common stock		(195,546)	(112,553)	0
Taxes paid related to net share settlements of equity awards		(4,210)	(2,640)	(6,451)
Issuances of common stock under employee stock purchase plan		7,328	6,557	6,090
Payments for contingent consideration arrangements		(6,758)	(4,070)	(5,917)
Distributions to noncontrolling interests		(43)	(70)	(250)
Net cash used in financing activities		(245,456)	(171,907)	(19,247)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		(1,279)	4,046	2,592
(Decrease) increase in cash, cash equivalents, and restricted cash		(80,994)	543,642	(6,294)
Cash, cash equivalents, and restricted cash at beginning of year (1)	[1]	903,562	359,920	366,214
Cash, cash equivalents, and restricted cash at end of period (1)	[1]	$ 822,568	$ 903,562	$ 359,920

[1] Includes $1.2 million, $0.7 million, $1.1 million, and $2.3 million of restricted cash classified as “Prepaid expenses and other” in the Consolidated Balance Sheets as of December 31, 2021, 2020, 2019, and 2018, respectively.