Segment Information (Financial Information by Segment) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2024 USD ($) geographicDivision	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information
Revenues	$ 3,485	$ 3,285
Revenue from contract with customer	825	802
Depreciation and amortization expense	686	693
Equipment rentals gross profit	1,346	1,241
Capital expenditures	653	870
Assets	26,658		$ 25,589
Sales of rental equipment
Segment Reporting Information
Capital expenditures incurred but not yet paid	158		74
Equipment rentals
Segment Reporting Information
Revenues	2,929	2,740
Revenue from contract with customer	269	257
Sales of rental equipment
Segment Reporting Information
Revenues	383	388
Revenue from contract with customer	383	388
Sales of new equipment
Segment Reporting Information
Revenues	48	44
Revenue from contract with customer	48	44
Contractor supplies sales
Segment Reporting Information
Revenues	36	34
Revenue from contract with customer	36	34
Service and other revenues
Segment Reporting Information
Revenues	89	79
Revenue from contract with customer	89	79
Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	$ 1,103	1,003
General rentals
Segment Reporting Information
Number of geographic divisions entity operates in (locations) | geographicDivision	4
Revenues	$ 2,546	2,479
Depreciation and amortization expense	574	577
Capital expenditures	506	683
Assets	20,203		20,411
General rentals | Equipment rentals
Segment Reporting Information
Revenues	2,070	2,018
General rentals | Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	346	350
General rentals | Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	29	18
General rentals | Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	20	21
General rentals | Service and other revenues
Segment Reporting Information
Revenue from contract with customer	81	72
General rentals | Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	681	663
Specialty
Segment Reporting Information
Revenues	939	806
Depreciation and amortization expense	112	116
Capital expenditures	147	187
Assets	6,455		$ 5,178
Specialty | Equipment rentals
Segment Reporting Information
Revenues	859	722
Specialty | Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	37	38
Specialty | Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	19	26
Specialty | Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	16	13
Specialty | Service and other revenues
Segment Reporting Information
Revenue from contract with customer	8	7
Specialty | Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	$ 422	$ 340