Guarantor And Non-Guarantor Consolidating Condensed Financial Statements (Consolidating Condensed Statements Of Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues
Vehicle rental	$ 1,832	$ 1,810	$ 4,684	$ 4,692
Other	745	732	1,916	1,906
Net revenues	2,577	2,542	6,600	6,598
Expenses
Operating	1,202	1,168	3,279	3,273
Vehicle depreciation and lease charges, net	555	582	1,485	1,532
Selling, general and administrative	314	298	843	833
Vehicle interest, net	75	77	218	213
Non-vehicle related depreciation and amortization	56	46	161	132
Interest expense	49	50	146	161
Intercompany Interest Expense Income	0	0	0	0
Early Debt Extinguishment			23	56
Transaction-related costs	8	7	57	23
Total expenses	2,265	2,236	6,222	6,239
Interest expense related to corporate debt, net:
Income before income taxes	312	306	378	359
Provision for (benefit from) income taxes	(128)	(114)	(60)	(137)
Equity in earnings (loss) of subsidiaries	0	0	0	0
Net income	184	192	318	222
Comprehensive income (loss)	(150)	(116)	(198)	(154)
Restructuring Charges	6	8	10	16
Parent Company [Member]
Revenues
Vehicle rental	0	0	0	0
Other	0	0	0	0
Net revenues	0	0	0	0
Expenses
Operating	0	4	1	6
Vehicle depreciation and lease charges, net	0	0	0	0
Selling, general and administrative	7	7	24	20
Vehicle interest, net	0	0	0	0
Non-vehicle related depreciation and amortization	0	0	0	0
Interest expense	0	1	0	2
Intercompany Interest Expense Income	(3)	(3)	(9)	(9)
Early Debt Extinguishment			0	0
Transaction-related costs	0	0	0	0
Total expenses	4	9	16	19
Interest expense related to corporate debt, net:
Income before income taxes	(4)	(9)	(16)	(19)
Provision for (benefit from) income taxes	1	2	6	5
Equity in earnings (loss) of subsidiaries	187	199	328	236
Net income	184	192	318	222
Comprehensive income (loss)	(150)	(116)	(198)	(154)
Restructuring Charges	0	0	0	0
Subsidiary Issuers [Member]
Revenues
Vehicle rental	0	0	0	0
Other	0	0	0	0
Net revenues	0	0	0	0
Expenses
Operating	3	1	12	9
Vehicle depreciation and lease charges, net	1	1	1	1
Selling, general and administrative	5	4	11	15
Vehicle interest, net	0	0	0	0
Non-vehicle related depreciation and amortization	0	0	1	1
Interest expense	39	36	121	124
Intercompany Interest Expense Income	(3)	(4)	(8)	(9)
Early Debt Extinguishment			23	56
Transaction-related costs	2	2	20	6
Total expenses	47	40	181	203
Interest expense related to corporate debt, net:
Income before income taxes	(47)	(40)	(181)	(203)
Provision for (benefit from) income taxes	18	21	165	85
Equity in earnings (loss) of subsidiaries	216	218	344	354
Net income	187	199	328	236
Comprehensive income (loss)	(155)	(123)	(210)	(167)
Restructuring Charges	0	0	0	0
Guarantor Subsidiaries [Member]
Revenues
Vehicle rental	1,196	1,161	3,193	3,126
Other	336	327	910	903
Net revenues	1,532	1,488	4,103	4,029
Expenses
Operating	716	674	1,978	1,938
Vehicle depreciation and lease charges, net	485	528	1,397	1,474
Selling, general and administrative	175	162	477	459
Vehicle interest, net	53	54	154	150
Non-vehicle related depreciation and amortization	33	27	99	82
Interest expense	1	(1)	(6)	1
Intercompany Interest Expense Income	5	0	11	1
Early Debt Extinguishment			0	0
Transaction-related costs	2	1	3	0
Total expenses	1,474	1,446	4,118	4,108
Interest expense related to corporate debt, net:
Income before income taxes	58	42	(15)	(79)
Provision for (benefit from) income taxes	(101)	(91)	(162)	(161)
Equity in earnings (loss) of subsidiaries	259	267	521	594
Net income	216	218	344	354
Comprehensive income (loss)	(186)	(140)	(230)	(284)
Restructuring Charges	4	1	5	3
Non-Guarantor Subsidiaries [Member]
Revenues
Vehicle rental	636	649	1,491	1,566
Other	951	988	2,570	2,634
Net revenues	1,587	1,637	4,061	4,200
Expenses
Operating	483	489	1,288	1,320
Vehicle depreciation and lease charges, net	556	581	1,487	1,529
Selling, general and administrative	127	125	331	339
Vehicle interest, net	77	78	228	222
Non-vehicle related depreciation and amortization	23	19	61	49
Interest expense	9	14	31	34
Intercompany Interest Expense Income	1	7	6	17
Early Debt Extinguishment			0	0
Transaction-related costs	4	4	34	17
Total expenses	1,282	1,324	3,471	3,540
Interest expense related to corporate debt, net:
Income before income taxes	305	313	590	660
Provision for (benefit from) income taxes	(46)	(46)	(69)	(66)
Equity in earnings (loss) of subsidiaries	0	0	0	0
Net income	259	267	521	594
Comprehensive income (loss)	(228)	(189)	(406)	(524)
Restructuring Charges	2	7	5	13
Eliminations [Member]
Revenues
Vehicle rental	0	0	0	0
Other	(542)	(583)	(1,564)	(1,631)
Net revenues	(542)	(583)	(1,564)	(1,631)
Expenses
Operating	0	0	0	0
Vehicle depreciation and lease charges, net	(487)	(528)	(1,400)	(1,472)
Selling, general and administrative	0	0	0	0
Vehicle interest, net	(55)	(55)	(164)	(159)
Non-vehicle related depreciation and amortization	0	0	0	0
Interest expense	0	0	0	0
Intercompany Interest Expense Income	0	0	0	0
Early Debt Extinguishment			0	0
Transaction-related costs	0	0	0	0
Total expenses	(542)	(583)	(1,564)	(1,631)
Interest expense related to corporate debt, net:
Income before income taxes	0	0	0	0
Provision for (benefit from) income taxes	0	0	0	0
Equity in earnings (loss) of subsidiaries	(662)	(684)	(1,193)	(1,184)
Net income	(662)	(684)	(1,193)	(1,184)
Comprehensive income (loss)	569	452	846	975
Restructuring Charges	$ 0	$ 0	$ 0	$ 0