Summary of Segments Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net revenues	$ 8,485	$ 7,937	$ 7,357
Vehicle depreciation and lease charges, net	1,996	1,811	1,471
Vehicle interest, net	282	264	297
Adjusted EBITDA	876	769	840
Non-vehicle depreciation and amortization	180	152	125
Assets exclusive of assets under vehicle programs	5,911	5,832	5,119
Assets under vehicle programs	11,058	10,452	10,099
Capital expenditures (excluding vehicles)	182	152	132
North America
Segment Reporting Information [Line Items]
Net revenues	5,533	5,042	4,640
Vehicle depreciation and lease charges, net	1,413	1,254	943
Vehicle interest, net	221	203	246
Adjusted EBITDA	607	508	557
Non-vehicle depreciation and amortization	120	101	78
Assets exclusive of assets under vehicle programs	3,881	3,718	3,065
Assets under vehicle programs	8,745	7,939	7,394
Capital expenditures (excluding vehicles)	107	98	72
International
Segment Reporting Information [Line Items]
Net revenues	2,588	2,522	2,342
Vehicle depreciation and lease charges, net	517	509	483
Vehicle interest, net	50	49	38
Adjusted EBITDA	290	272	270
Non-vehicle depreciation and amortization	59	50	46
Assets exclusive of assets under vehicle programs	1,778	1,809	1,740
Assets under vehicle programs	1,967	2,164	2,300
Capital expenditures (excluding vehicles)	72	54	60
Truck Rental
Segment Reporting Information [Line Items]
Net revenues	364	373	374
Vehicle depreciation and lease charges, net	66	48	45
Vehicle interest, net	11	12	13
Adjusted EBITDA	39	36	34
Non-vehicle depreciation and amortization	1	1	1
Assets exclusive of assets under vehicle programs	77	80	90
Assets under vehicle programs	346	349	405
Capital expenditures (excluding vehicles)	3		0
Corporate and Other
Segment Reporting Information [Line Items]
Net revenues	0	0	1
Adjusted EBITDA	(60)	(47)	(21)
Assets exclusive of assets under vehicle programs	$ 175	$ 225	$ 224