Investments in Affiliates and Other Entities - Equity Method Investments (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2022 USD ($) investment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Distributions to non-controlling interests		$ 10,241	$ 9,946	$ 6,357
Accounts receivable, net	$ 3,674,525	4,410,829	3,674,525
Accounts payable and accrued expenses	2,153,129	3,061,242	2,153,129
Revenues		20,882,206	17,073,903	12,980,213
Cost of services		17,945,120	14,544,748	11,026,954
Equity in earnings of integral unconsolidated affiliates		41,609	52,466	44,061
Carrying amount that exceed share of underlying net equity in net assets	37,800	31,400	37,800
Amortization of the basis difference		6,200	1,900	500
Non-controlling Interests
Summary Of Significant Accounting Policies [Line Items]
Distributions to non-controlling interests		10,241	9,946	6,357
Integral Affiliates | Related Party
Summary Of Significant Accounting Policies [Line Items]
Accounts receivable, net	96,900	96,400	96,900
Accounts payable and accrued expenses	$ 9,300	24,500	9,300
Revenues		215,000	154,700	74,100
Cost of services		201,300	134,500	116,200
Integral Unconsolidated Affiliates
Summary Of Significant Accounting Policies [Line Items]
Equity in earnings of integral unconsolidated affiliates		41,600	52,500	44,100
Non-Integral Unconsolidated Affiliates
Summary Of Significant Accounting Policies [Line Items]
Number of investments sold | investment	1
Realized gain (loss) on disposal	$ 25,900
Total consideration		58,500
Equity in earnings of integral unconsolidated affiliates		1,300	$ 20,300	$ 2,100
Non-Integral Unconsolidated Affiliates | Non-controlling Interests
Summary Of Significant Accounting Policies [Line Items]
Realized gain (loss) on disposal	$ 10,400
Distributions to non-controlling interests		9,800
Integral and Non-Integral Unconsolidated Affiliates
Summary Of Significant Accounting Policies [Line Items]
Undistributed earnings of unconsolidated affiliates		$ 18,700