Segment Information (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Segment Reporting, Change in Measurement Method		$ 15		$ 34
Sales Revenue, Services, Net	$ 2,173	2,194	$ 4,023	4,056
Adjusted EBITDA	227	213	344	330
Non Vehicle Related Depreciation And Amortization	56	45	105	86
Restructuring expense	3	1	4	8
Loss before income taxes	82	48	66	53
Assets Under Vehicle Programs	14,120		14,120		$ 11,058
International
Segment Reporting Information [Line Items]
Segment Reporting, Change in Measurement Method		2		5
Sales Revenue, Services, Net	617	652	1,092	1,184
Adjusted EBITDA	61	55	77	69
Assets Under Vehicle Programs	2,800		2,800		1,900
Americas
Segment Reporting Information [Line Items]
Sales Revenue, Services, Net	1,556	1,542	2,931	2,872
Adjusted EBITDA	178	172	293	287
Assets Under Vehicle Programs	11,300		11,300		$ 9,200
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Services, Net	0	0	0	0
Adjusted EBITDA	$ (12)	$ (14)	$ (26)	$ (26)