Segment Information (Financial Information by Segment) (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024 USD ($) geographicDivision	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) geographicDivision	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information
Total revenues	$ 3,773	$ 3,554	$ 7,258	$ 6,839
Revenue from contract with customer	870	852	1,695	1,654
Depreciation and amortization expense	717	696	1,403	1,389
Equipment rentals gross profit	1,518	1,425	2,864	2,666
Capital expenditures			2,181	2,227
Assets	$ 27,613		27,613		$ 25,589
Sales of rental equipment
Segment Reporting Information
Capital expenditures incurred but not yet paid			$ 224		74
General rentals
Segment Reporting Information
Number of geographic divisions entity operates in (locations) | geographicDivision	4		4
Total revenues	$ 2,653	2,653	$ 5,199	5,132
Depreciation and amortization expense	541	580	1,115	1,157
Capital expenditures			1,658	1,766
Assets	20,804		20,804		20,411
Specialty
Segment Reporting Information
Total revenues	1,120	901	2,059	1,707
Depreciation and amortization expense	176	116	288	232
Capital expenditures			523	461
Assets	6,809		6,809		$ 5,178
Equipment rentals
Segment Reporting Information
Total revenues	3,215	2,981	6,144	5,721
Revenue from contract with customer	312	279	581	536
Equipment rentals | General rentals
Segment Reporting Information
Total revenues	2,209	2,189	4,279	4,207
Equipment rentals | Specialty
Segment Reporting Information
Total revenues	1,006	792	1,865	1,514
Sales of rental equipment
Segment Reporting Information
Total revenues	365	382	748	770
Revenue from contract with customer	365	382	748	770
Sales of rental equipment | General rentals
Segment Reporting Information
Revenue from contract with customer	313	342	659	692
Sales of rental equipment | Specialty
Segment Reporting Information
Revenue from contract with customer	52	40	89	78
Sales of new equipment
Segment Reporting Information
Total revenues	61	70	109	114
Revenue from contract with customer	61	70	109	114
Sales of new equipment | General rentals
Segment Reporting Information
Revenue from contract with customer	27	24	56	42
Sales of new equipment | Specialty
Segment Reporting Information
Revenue from contract with customer	34	46	53	72
Contractor supplies sales
Segment Reporting Information
Total revenues	42	37	78	71
Revenue from contract with customer	42	37	78	71
Contractor supplies sales | General rentals
Segment Reporting Information
Revenue from contract with customer	23	23	43	44
Contractor supplies sales | Specialty
Segment Reporting Information
Revenue from contract with customer	19	14	35	27
Service and other revenues
Segment Reporting Information
Total revenues	90	84	179	163
Revenue from contract with customer	90	84	179	163
Service and other revenues | General rentals
Segment Reporting Information
Revenue from contract with customer	81	75	162	147
Service and other revenues | Specialty
Segment Reporting Information
Revenue from contract with customer	9	9	17	16
Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	1,285	1,173	2,388	2,176
Equipment rentals gross profit | General rentals
Segment Reporting Information
Equipment rentals gross profit	802	788	1,483	1,451
Equipment rentals gross profit | Specialty
Segment Reporting Information
Equipment rentals gross profit	$ 483	$ 385	$ 905	$ 725