Segment Information (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Segment Reporting, Change in Measurement Method		$ 15		$ 49
Sales Revenue, Services, Net	$ 2,577	2,542	$ 6,600	6,598
Adjusted EBITDA	431	417	775	747
Non Vehicle Related Depreciation And Amortization	56	46	161	132
Restructuring expense	6	8	10	16
Loss before income taxes	312	306	378	359
Assets Under Vehicle Programs	12,786		12,786		$ 11,058
International
Segment Reporting Information [Line Items]
Segment Reporting, Change in Measurement Method		2		7
Sales Revenue, Services, Net	801	800	1,893	1,984
Adjusted EBITDA	168	158	245	227
Assets Under Vehicle Programs	2,800		2,800		$ 1,900
Americas
Segment Reporting Information [Line Items]
Sales Revenue, Services, Net	1,776	1,742	4,707	4,614
Adjusted EBITDA	279	275	572	562
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Services, Net	0	0	0	0
Adjusted EBITDA	$ (16)	$ (16)	$ (42)	$ (42)