Segment Information (Financial Information by Segment) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) region	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information
Revenues	$ 2,057	$ 2,125
Depreciation and amortization expense	466	526
Equipment rentals gross profit	714	727
Capital expenditures	314	261
Assets	17,542		$ 17,868
Equipment rentals
Segment Reporting Information
Revenues	1,667	1,783
Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	267	208
Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	49	62
Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	24	25
Service and other revenues
Segment Reporting Information
Revenue from contract with customer	50	47
Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	$ 577	610
General rentals
Segment Reporting Information
Number of geographic regions entity operates in (locations) | region	11
Revenues	$ 1,622	1,694
Depreciation and amortization expense	380	437
Capital expenditures	284	198
Assets	14,814		15,051
General rentals | Equipment rentals
Segment Reporting Information
Revenues	1,273	1,394
General rentals | Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	247	190
General rentals | Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	42	53
General rentals | Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	16	16
General rentals | Service and other revenues
Segment Reporting Information
Revenue from contract with customer	44	41
General rentals | Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	411	448
Trench, power and fluid solutions
Segment Reporting Information
Revenues	435	431
Depreciation and amortization expense	86	89
Capital expenditures	30	63
Assets	2,728		$ 2,817
Trench, power and fluid solutions | Equipment rentals
Segment Reporting Information
Revenues	394	389
Trench, power and fluid solutions | Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	20	18
Trench, power and fluid solutions | Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	7	9
Trench, power and fluid solutions | Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	8	9
Trench, power and fluid solutions | Service and other revenues
Segment Reporting Information
Revenue from contract with customer	6	6
Trench, power and fluid solutions | Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	$ 166	$ 162