Segment and Geographic Information - Schedule of Geographic Distributions of Revenues, Equity in Earnings of Affiliates, Adjusted Segment EBITDA, Depreciation and Amortization, Assets and Goodwill and Other Intangible Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 64,968	$ 60,233	$ 58,752
Equity in losses (earnings) of affiliates	(22)	(45)	(113)
Adjusted segment EBITDA	12,726	12,067	12,644
Depreciation and amortization	3,077	2,969	2,853
Interest expense	1,938	1,741	1,566
Losses (gains) on sales of facilities	5	(1,301)	(1,620)
Losses on retirement of debt	0	78	12
Income before income taxes	7,706	8,580	9,833
Assets	56,211	52,438	50,742
Goodwill and other intangible assets, Beginning Balance	9,653	9,540	8,578
Goodwill and other intangible assets, Acquisitions	362	262	1,062
Foreign Currency Translation Amortization And Other	(70)	(149)	(100)
Goodwill and other intangible assets, Ending Balance	9,945	9,653	9,540
National Group [Member]
Segment Reporting Information [Line Items]
Revenues	18,105	16,767	16,329
Equity in losses (earnings) of affiliates	(2)	(1)	(33)
Adjusted segment EBITDA	4,000	3,616	4,202
Depreciation and amortization	834	801	754
Assets	12,487	11,793	11,236
Goodwill and other intangible assets, Beginning Balance	1,244	1,212	1,089
Goodwill and other intangible assets, Acquisitions	0	75	126
Foreign Currency Translation Amortization And Other	(3)	(43)	(3)
Goodwill and other intangible assets, Ending Balance	1,241	1,244	1,212
Atlantic Group [Member]
Segment Reporting Information [Line Items]
Revenues	21,167	19,324	19,098
Equity in losses (earnings) of affiliates	(3)	(3)	(2)
Adjusted segment EBITDA	4,492	3,881	4,218
Depreciation and amortization	989	921	848
Assets	16,098	15,092	13,944
Goodwill and other intangible assets, Beginning Balance	2,057	1,970	1,375
Goodwill and other intangible assets, Acquisitions	8	90	610
Foreign Currency Translation Amortization And Other	(1)	(3)	(15)
Goodwill and other intangible assets, Ending Balance	2,064	2,057	1,970
American Group [Member]
Segment Reporting Information [Line Items]
Revenues	22,318	20,858	19,636
Equity in losses (earnings) of affiliates	(59)	(43)	(50)
Adjusted segment EBITDA	5,208	5,102	4,836
Depreciation and amortization	971	937	897
Assets	19,786	17,934	17,224
Goodwill and other intangible assets, Beginning Balance	5,152	5,062	4,996
Goodwill and other intangible assets, Acquisitions	326	90	66
Foreign Currency Translation Amortization And Other	0	0	0
Goodwill and other intangible assets, Ending Balance	5,478	5,152	5,062
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	3,378	3,284	3,689
Equity in losses (earnings) of affiliates	42	2	(28)
Adjusted segment EBITDA	(974)	(532)	(612)
Depreciation and amortization	283	310	354
Assets	7,840	7,619	8,338
Goodwill and other intangible assets, Beginning Balance	1,200	1,296	1,118
Goodwill and other intangible assets, Acquisitions	28	7	260
Foreign Currency Translation Amortization And Other	(66)	(103)	(82)
Goodwill and other intangible assets, Ending Balance	$ 1,162	$ 1,200	$ 1,296