Segment Information (Summary Of Segments Information) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Assets Under Vehicle Programs	$ 12,304		$ 11,578
Document Fiscal Year Focus	2017
Revenues	$ 1,839	$ 1,881
Adjusted EBITDA	(27)	44
Non-vehicle related depreciation and amortization	63	61
Interest expense	49	50
Early extinguishment of debt	(3)	0
Early extinguishment of debt	3
Transaction-related costs, net	3	4
Charges for legal matter	13	0
Restructuring expense	7	15
Income before income taxes	(165)	(86)
International
Segment Reporting Information [Line Items]
Revenues	1,314	1,364
Adjusted EBITDA	(20)	63
International
Segment Reporting Information [Line Items]
Revenues	525	517
Adjusted EBITDA	7	1
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Adjusted EBITDA	$ (14)	$ (20)