Segment Information (Financial Information by Segment) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) region	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) region	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information
Revenues	$ 1,939	$ 2,290	$ 4,064	$ 4,407
Depreciation and amortization expense	490	504	1,016	1,003
Equipment rentals gross profit	701	911	1,428	1,672
Capital expenditures			455	1,226
Assets	17,900		17,900		$ 18,970
Equipment rentals
Segment Reporting Information
Revenues	1,642	1,960	3,425	3,755
Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	176	197	384	389
Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	53	60	115	122
Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	23	27	48	51
Service and other revenues
Segment Reporting Information
Revenue from contract with customer	45	46	92	90
Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	$ 600	792	$ 1,210	1,450
General rentals
Segment Reporting Information
Number of geographic regions entity operates in (locations) | region	11		11
Revenues	$ 1,512	1,818	$ 3,206	3,528
Depreciation and amortization expense	401	416	838	828
Capital expenditures			377	1,015
Assets	15,109		15,109		16,036
General rentals | Equipment rentals
Segment Reporting Information
Revenues	1,255	1,527	2,649	2,950
General rentals | Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	158	180	348	358
General rentals | Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	45	52	98	107
General rentals | Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	15	19	31	36
General rentals | Service and other revenues
Segment Reporting Information
Revenue from contract with customer	39	40	80	77
General rentals | Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	419	593	867	1,094
Trench, power and fluid solutions
Segment Reporting Information
Revenues	427	472	858	879
Depreciation and amortization expense	89	88	178	175
Capital expenditures			78	211
Assets	2,791		2,791		$ 2,934
Trench, power and fluid solutions | Equipment rentals
Segment Reporting Information
Revenues	387	433	776	805
Trench, power and fluid solutions | Sales of rental equipment
Segment Reporting Information
Revenue from contract with customer	18	17	36	31
Trench, power and fluid solutions | Sales of new equipment
Segment Reporting Information
Revenue from contract with customer	8	8	17	15
Trench, power and fluid solutions | Contractor supplies sales
Segment Reporting Information
Revenue from contract with customer	8	8	17	15
Trench, power and fluid solutions | Service and other revenues
Segment Reporting Information
Revenue from contract with customer	6	6	12	13
Trench, power and fluid solutions | Equipment rentals gross profit
Segment Reporting Information
Equipment rentals gross profit	$ 181	$ 199	$ 343	$ 356