Investments in Affiliates and Other Entities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Schedule of Equity Method Investments [Line Items]
Distributions to non-controlling interests	$ 985	$ 8,199
Accounts receivable, net	5,289,723		$ 5,170,935
Accounts payable and accrued expenses	3,667,510		3,722,343
Revenues	6,233,334	5,031,819
Cost of services	5,399,297	4,408,325
Equity in earnings of integral unconsolidated affiliates	12,929	12,334
Carrying amount that exceed share of underlying net equity in net assets	43,800		44,500
Amortization of equity method investment, difference between carrying amount and underlying equity	700	1,500
Non-Integral Unconsolidated Affiliates
Schedule of Equity Method Investments [Line Items]
Realized gain (loss) on disposal		12,200
Cash received		34,900
Equity in earnings (loss) of non-integral unconsolidated affiliates	100	3,600
Non-Integral Unconsolidated Affiliates, Non-controlling Interest
Schedule of Equity Method Investments [Line Items]
Realized gain (loss) on disposal		4,900
Distributions to non-controlling interests		4,900
Integral Affiliates | Related Party
Schedule of Equity Method Investments [Line Items]
Accounts receivable, net	138,000		133,300
Accounts payable and accrued expenses	26,100		$ 15,400
Revenues	51,100	59,000
Cost of services	94,900	88,900
Integral Unconsolidated Affiliates | Related Party
Schedule of Equity Method Investments [Line Items]
Equity in earnings of integral unconsolidated affiliates	12,900	$ 12,300
Integral and Non-Integral Unconsolidated Affiliates
Schedule of Equity Method Investments [Line Items]
Undistributed earnings of unconsolidated affiliates	$ 56,100