Segment Information (Reconciliation to Consolidated Totals) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	$ 1,161	$ 1,103	$ 875	$ 714	$ 869	$ 886	$ 701	$ 727	$ 3,853	$ 3,183	$ 3,670
Selling, general and administrative expenses									(1,199)	(979)	(1,092)
Merger related costs (1)									(3)	0	(1)
Restructuring charge (2)									(2)	(17)	(18)
Non-rental depreciation and amortization									(372)	(387)	(407)
Interest expense, net									(424)	(669)	(648)
Other (expense) income, net									(7)	8	10
Income before provision for income taxes									1,846	1,139	1,514
Equipment rentals
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit									3,267	2,719	3,207
Other products and services
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit									$ 586	$ 464	$ 463