Segment and Geographic Information - Schedule of Geographic Distributions of Revenues, Equity in Earnings of Affiliates, Adjusted Segment EBITDA, Depreciation and Amortization and Assets (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues	$ 60,233	$ 58,752	$ 51,533
Equity in earnings of affiliates	(45)	(113)	(54)
Adjusted segment EBITDA	12,067	12,644	10,037
Depreciation and amortization	2,969	2,853	2,721
Interest expense	1,741	1,566	1,584
Losses (gains) on sales of facilities	(1,301)	(1,620)	7
Losses on retirement of debt	78	12	295
Income before income taxes	8,580	9,833	5,430
Assets	52,438	50,742	47,490
Goodwill and other intangible assets, Beginning Balance	9,540	8,578	8,269
Goodwill and other intangible assets, Acquisitions	262	1,062	344
Foreign Currency Translation Amortization And Other	(149)	(100)	(35)
Goodwill and other intangible assets, Ending Balance	9,653	9,540	8,578
National Group [Member]
Segment Reporting Information [Line Items]
Revenues	30,350	29,826	25,694
Equity in earnings of affiliates	(4)	(33)	(28)
Adjusted segment EBITDA	6,379	7,200	5,532
Depreciation and amortization	1,464	1,359	1,216
Assets	22,863	21,205	18,913
Goodwill and other intangible assets, Beginning Balance	2,492	1,775	1,739
Goodwill and other intangible assets, Acquisitions	165	735	38
Foreign Currency Translation Amortization And Other	(5)	(18)	(2)
Goodwill and other intangible assets, Ending Balance	2,652	2,492	1,775
American Group [Member]
Segment Reporting Information [Line Items]
Revenues	26,865	26,152	23,593
Equity in earnings of affiliates	(43)	(53)	(42)
Adjusted segment EBITDA	6,055	6,156	5,333
Depreciation and amortization	1,219	1,183	1,164
Assets	22,216	21,428	20,760
Goodwill and other intangible assets, Beginning Balance	5,832	5,775	5,765
Goodwill and other intangible assets, Acquisitions	91	67	27
Foreign Currency Translation Amortization And Other	(62)	(10)	(17)
Goodwill and other intangible assets, Ending Balance	5,861	5,832	5,775
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	3,018	2,774	2,246
Equity in earnings of affiliates	2	(27)	16
Adjusted segment EBITDA	(367)	(712)	(828)
Depreciation and amortization	286	311	341
Assets	7,359	8,109	7,817
Goodwill and other intangible assets, Beginning Balance	1,216	1,028	765
Goodwill and other intangible assets, Acquisitions	6	260	279
Foreign Currency Translation Amortization And Other	(82)	(72)	(16)
Goodwill and other intangible assets, Ending Balance	$ 1,140	$ 1,216	$ 1,028

Segment and Geographic Information - Schedule of Geographic Distributions of Revenues, Equity in Earnings of Affiliates, Adjusted Segment EBITDA, Depreciation and Amortization and Assets (Detail) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Segment Reporting Information [Line Items]

Revenues

$ 60,233

$ 58,752

$ 51,533

Equity in earnings of affiliates

(45)

(113)