Segment Information (Financial Information by Segment) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) region	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information
Revenues	$ 2,125	$ 2,117
Depreciation and amortization expense	526	499
Equipment rentals gross profit	727	761
Capital expenditures	261	299
Assets	18,868		$ 18,970
Equipment rentals
Segment Reporting Information
Revenues	1,783	1,795
Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	208	192
Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	62	62
Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	25	24
Service and other revenues
Segment Reporting Information
Revenue from contract with customer	47	44
Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	$ 610	658
General rentals
Segment Reporting Information
Number of geographic regions entity operates in (locations) | region	11
Revenues	$ 1,694	1,710
Depreciation and amortization expense	437	412
Capital expenditures	198	236
Assets	15,994		16,036
General rentals | Equipment rentals
Segment Reporting Information
Revenues	1,394	1,423
General rentals | Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	190	178
General rentals | Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	53	55
General rentals | Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	16	17
General rentals | Service and other revenues
Segment Reporting Information
Revenue from contract with customer	41	37
General rentals | Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	448	501
Trench, power and fluid solutions
Segment Reporting Information
Revenues	431	407
Depreciation and amortization expense	89	87
Capital expenditures	63	63
Assets	2,874		$ 2,934
Trench, power and fluid solutions | Equipment rentals
Segment Reporting Information
Revenues	389	372
Trench, power and fluid solutions | Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	18	14
Trench, power and fluid solutions | Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	9	7
Trench, power and fluid solutions | Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	9	7
Trench, power and fluid solutions | Service and other revenues
Segment Reporting Information
Revenue from contract with customer	6	7
Trench, power and fluid solutions | Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	$ 162	$ 157