Segments and Related Information - Foreign Operations (Details) - USD ($) $ in Thousands				12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment and Related Information [Line Items]
Revenue				$ 7,951,781	$ 6,320,975	$ 7,183,188
United States
Segment and Related Information [Line Items]
Revenue				7,800,000	6,200,000	6,900,000
Property and equipment, net	$ 1,411,600	$ 959,500	$ 874,700	1,411,600	959,500	874,700
Intangible assets and goodwill, net	2,100,000	2,100,000	1,400,000	2,100,000	2,100,000	1,400,000
Foreign Operations
Segment and Related Information [Line Items]
Revenue				165,200	133,100	233,500
Property and equipment, net	24,500	22,800	31,100	24,500	22,800	31,100
Intangible assets and goodwill, net	$ 43,800	$ 50,500	$ 56,400	$ 43,800	$ 50,500	$ 56,400
Accounts Receivable, Net, Less Contract Liabilities | Geographic Concentration Risk | Foreign Operations
Segment and Related Information [Line Items]
Concentration risk, percentage of total	2.00%	5.00%	5.00%
Revenue Benchmark | Customer Concentration Risk | Government Transactions
Segment and Related Information [Line Items]
Concentration risk, percentage of total				5.00%	2.00%	1.00%