Segment and Geographic Information - Schedule of Geographic Distributions of Revenues, Equity in Earnings of Affiliates, Adjusted Segment EBITDA, Depreciation and Amortization (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Revenues	$ 15,861	$ 14,820	$ 31,452	$ 29,765
Equity in losses (earnings) of affiliates	7	(8)	25	(19)
Adjusted segment EBITDA	3,056	3,042	6,228	5,986
Depreciation and amortization	763	738	1,519	1,470
Interest expense	485	434	964	842
Losses (gains) on sales of facilities	(1)	32	14	22
Losses on retirement of debt	0	78	0	78
Income before income taxes	1,809	1,760	3,731	3,574
National Group [Member]
Segment Reporting Information [Line Items]
Revenues	4,372	4,088	8,988	8,290
Equity in losses (earnings) of affiliates	(1)	(1)	(2)	(1)
Adjusted segment EBITDA	878	867	2,027	1,822
Depreciation and amortization	208	194	415	391
Atlantic Group [Member]
Segment Reporting Information [Line Items]
Revenues	5,038	4,700	10,147	9,386
Equity in losses (earnings) of affiliates	(1)	(1)	(2)	(1)
Adjusted segment EBITDA	975	969	2,061	1,819
Depreciation and amortization	247	233	486	455
American Group [Member]
Segment Reporting Information [Line Items]
Revenues	5,536	5,205	10,735	10,411
Equity in losses (earnings) of affiliates	(10)	(9)	(22)	(18)
Adjusted segment EBITDA	1,319	1,338	2,452	2,654
Depreciation and amortization	238	233	475	465
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	915	827	1,582	1,678
Equity in losses (earnings) of affiliates	19	3	51	1
Adjusted segment EBITDA	(116)	(132)	(312)	(309)
Depreciation and amortization	$ 70	$ 78	$ 143	$ 159