Acquisitions (Pro Forma Information) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Apr. 30, 2017
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenues	$ 1,766,000,000	$ 1,508,000,000	$ 4,719,000,000	$ 4,239,000,000
Pro forma revenues	1,766,000,000	1,603,000,000	4,800,000,000	4,505,000,000
Pretax income (loss)	322,000,000	303,000,000	712,000,000	667,000,000
Combined pretax income	322,000,000	309,000,000	700,000,000	678,000,000
Pro forma pretax income	332,000,000	290,000,000	737,000,000	615,000,000
Impact of fair value mark-ups/useful life changes on depreciation
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pretax income (loss)	0	(9,000,000)	(9,000,000)	(28,000,000)
Impact of the fair value mark-up of acquired NES fleet on cost of rental equipment sales
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pretax income (loss)	0	(1,000,000)	(1,000,000)	(1,000,000)
Gain on sale of equity interest
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pretax income (loss)	0	0	0	(7,000,000)
Interest expense
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pretax income (loss)	0	(9,000,000)	(9,000,000)	(28,000,000)
Elimination of historic NES interest
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pretax income (loss)	0	9,000,000	12,000,000	28,000,000
Elimination of merger related costs
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pretax income (loss)	1,000,000	0	17,000,000	0
Restructuring charges
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pretax income (loss)	9,000,000	(9,000,000)	27,000,000	(27,000,000)
NES Rentals Holdings II, Inc.
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenues	0	95,000,000	81,000,000	266,000,000
Pretax income (loss)	$ 0	$ 6,000,000	$ (12,000,000)	$ 11,000,000
URNA | Senior notes | 5 1/2 percent Senior Notes due 2027 and 5 7/8 percent Senior Notes issued to fund NES acquisition
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Face amount					$ 500,000,000