Segment Information (Reconciliation to Income (loss) from Continuing Operations) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Equipment rentals gross profit	$ 886	$ 1,033	$ 2,314	$ 2,705
Selling, general and administrative expenses	(232)	(273)	(721)	(824)
Merger related costs	0	0	0	(1)
Restructuring charge	(6)	(2)	(11)	(16)
Non-rental depreciation and amortization	(97)	(102)	(292)	(311)
Interest expense, net	(278)	(147)	(544)	(478)
Other income, net	2	1	6	6
Income before provision for income taxes	275	510	752	1,081
Total equipment rentals gross profit
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Equipment rentals gross profit	777	917	1,987	2,367
Gross profit from other lines of business
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Equipment rentals gross profit	$ 109	$ 116	$ 327	$ 338