Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Revenues	$ 4,459,757	$ 3,353,278	$ 12,657,285	$ 9,056,675
Cost of services (including related depreciation)	3,770,927	2,818,602	10,795,694	7,701,398
Gross profit	688,830	534,676	1,861,591	1,355,277
Equity in earnings of integral unconsolidated affiliates	10,633	10,232	44,350	22,865
Selling, general and administrative expenses	(347,449)	(274,846)	(995,581)	(788,308)
Amortization of intangible assets	(67,147)	(22,772)	(290,843)	(65,418)
Asset impairment charges	0	0	(2,800)	(2,319)
Change in fair value of contingent consideration liabilities	1,924	787	(4,054)	1,360
Operating income	286,791	248,077	612,663	523,457
Interest and other financing expenses	(33,566)	(17,259)	(86,933)	(42,843)
Interest income	436	72	727	3,098
Other income (expense), net	(24,455)	6,089	(68,255)	18,232
Income before income taxes	229,206	236,979	458,202	501,944
Provision for income taxes	72,890	61,581	120,698	116,256
Net income	156,316	175,398	337,504	385,688
Less: Net income attributable to non-controlling interests	360	1,033	8,887	4,529
Net income attributable to common stock	$ 155,956	$ 174,365	$ 328,617	$ 381,159
Earnings per share attributable to common stock:
Basic (in dollars per share)	$ 1.09	$ 1.25	$ 2.29	$ 2.72
Diluted (in dollars per share)	$ 1.06	$ 1.21	$ 2.22	$ 2.64
Shares used in computing earnings per share:
Weighted average basic shares outstanding (in shares)	143,353,000	140,008,000	143,581,000	140,134,000
Weighted average diluted shares outstanding (in shares)	147,678,000	144,304,000	148,096,000	144,448,000