Segment Information (Reconciliation to Income (loss) from Continuing Operations) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Equipment rentals gross profit	$ 1,033	$ 938	$ 2,705	$ 2,366
Selling, general and administrative expenses	(273)	(265)	(824)	(736)
Merger related costs	0	(11)	(1)	(14)
Restructuring charge	(2)	(9)	(16)	(15)
Non-rental depreciation and amortization	(102)	(75)	(311)	(213)
Interest expense, net	(147)	(118)	(478)	(339)
Other income, net	1	0	6	2
Income before provision for income taxes	510	460	1,081	1,051
Equipment rentals under operating lease
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Equipment rentals gross profit	917	847	2,367	2,080
Other lines of business
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Equipment rentals gross profit	$ 116	$ 91	$ 338	$ 286

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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