Guarantor And Non-Guarantor Consolidating Condensed Financial Statements (Consolidating Condensed Statements Of Comprehensive Income) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues
Vehicle rental	$ 1,810	$ 1,734	$ 4,692	$ 4,388
Other	732	661	1,906	1,699
Net revenues	2,542	2,395	6,598	6,087
Expenses
Operating	1,168	1,142	3,273	3,080
Vehicle depreciation and lease charges, net	582	524	1,532	1,387
Selling, general and administrative	298	274	833	771
Vehicle interest, net	77	72	213	195
Non-vehicle related depreciation and amortization	46	39	132	109
Interest expense	50	57	161	170
Intercompany Interest Expense Income	0	0	0	0
Early extinguishment of debt	0	0	56	131
Transaction-related costs	7	10	23	37
Total expenses	2,236	2,165	6,239	5,952
Interest expense related to corporate debt, net:
Income before income taxes	306	230	359	135
Provision for (benefit from) income taxes	(114)	(112)	(137)	(91)
Equity in earnings (loss) of subsidiaries	0	0	0	0
Net income	192	118	222	44
Comprehensive income (loss)	(116)	(178)	(154)	(44)
Restructuring Charges	8	14	16	39
Other than Temporary Impairment Losses, Investments	0	33	0	33
Parent Company [Member]
Revenues
Vehicle rental	0	0	0	0
Other	0	0	0	0
Net revenues	0	0	0	0
Expenses
Operating	4	2	6	6
Vehicle depreciation and lease charges, net	0	0	0	0
Selling, general and administrative	7	9	20	25
Vehicle interest, net	0	0	0	0
Non-vehicle related depreciation and amortization	0	0	0	0
Interest expense	1	1	2	3
Intercompany Interest Expense Income	(3)	(3)	(9)	(9)
Early extinguishment of debt			0	41
Transaction-related costs	0	0	0	1
Total expenses	9	9	19	67
Interest expense related to corporate debt, net:
Income before income taxes	(9)	(9)	(19)	(67)
Provision for (benefit from) income taxes	2	2	5	9
Equity in earnings (loss) of subsidiaries	199	125	236	102
Net income	192	118	222	44
Restructuring Charges	0	0	0	0
Other than Temporary Impairment Losses, Investments		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	1	5	9	8
Vehicle depreciation and lease charges, net	1	0	1	0
Selling, general and administrative	4	1	15	4
Vehicle interest, net	0	0	0	0
Non-vehicle related depreciation and amortization	0	0	1	1
Interest expense	36	49	124	147
Intercompany Interest Expense Income	(4)	(7)	(9)	(23)
Early extinguishment of debt			56	90
Transaction-related costs	2	8	6	21
Total expenses	40	89	203	281
Interest expense related to corporate debt, net:
Income before income taxes	(40)	(89)	(203)	(281)
Provision for (benefit from) income taxes	21	21	85	96
Equity in earnings (loss) of subsidiaries	218	193	354	287
Net income	199	125	236	102
Comprehensive income (loss)	(123)	(183)	(167)	(101)
Restructuring Charges	0	0	0	0
Other than Temporary Impairment Losses, Investments		33		33
Guarantor Subsidiaries [Member]
Revenues
Vehicle rental	1,161	1,100	3,126	2,909
Other	327	308	903	842
Net revenues	1,488	1,408	4,029	3,751
Expenses
Operating	674	672	1,938	1,843
Vehicle depreciation and lease charges, net	528	338	1,474	924
Selling, general and administrative	162	155	459	450
Vehicle interest, net	54	48	150	136
Non-vehicle related depreciation and amortization	27	25	82	71
Interest expense	(1)	0	1	0
Intercompany Interest Expense Income	0	1	1	5
Early extinguishment of debt			0	0
Transaction-related costs	1	0	0	1
Total expenses	1,446	1,246	4,108	3,453
Interest expense related to corporate debt, net:
Income before income taxes	42	162	(79)	298
Provision for (benefit from) income taxes	(91)	(93)	(161)	(141)
Equity in earnings (loss) of subsidiaries	267	124	594	130
Net income	218	193	354	287
Comprehensive income (loss)	(140)	(250)	(284)	(285)
Restructuring Charges	1	7	3	23
Other than Temporary Impairment Losses, Investments		0		0
Non-Guarantor Subsidiaries [Member]
Revenues
Vehicle rental	649	634	1,566	1,479
Other	988	740	2,634	1,910
Net revenues	1,637	1,374	4,200	3,389
Expenses
Operating	489	463	1,320	1,223
Vehicle depreciation and lease charges, net	581	382	1,529	949
Selling, general and administrative	125	109	339	292
Vehicle interest, net	78	74	222	195
Non-vehicle related depreciation and amortization	19	14	49	37
Interest expense	14	7	34	20
Intercompany Interest Expense Income	7	9	17	27
Early extinguishment of debt			0	0
Transaction-related costs	4	2	17	14
Total expenses	1,324	1,067	3,540	2,773
Interest expense related to corporate debt, net:
Income before income taxes	313	307	660	616
Provision for (benefit from) income taxes	(46)	(42)	(66)	(55)
Equity in earnings (loss) of subsidiaries	0	0	0	0
Net income	267	265	594	561
Comprehensive income (loss)	(189)	(303)	(524)	(542)
Restructuring Charges	7	7	13	16
Other than Temporary Impairment Losses, Investments		0		0
Eliminations [Member]
Revenues
Vehicle rental	0	0	0	0
Other	(583)	(387)	(1,631)	(1,053)
Net revenues	(583)	(387)	(1,631)	(1,053)
Expenses
Operating	0	0	0	0
Vehicle depreciation and lease charges, net	(528)	(196)	(1,472)	(486)
Selling, general and administrative	0	0	0	0
Vehicle interest, net	(55)	(50)	(159)	(136)
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 extinguishment of debt			0	0
Transaction-related costs	0	0	0	0
Total expenses	(583)	(246)	(1,631)	(622)
Interest expense related to corporate debt, net:
Income before income taxes	0	(141)	0	(431)
Provision for (benefit from) income taxes	0	0	0	0
Equity in earnings (loss) of subsidiaries	(684)	(442)	(1,184)	(519)
Net income	(684)	(583)	(1,184)	(950)
Comprehensive income (loss)	452	736	975	928
Restructuring Charges	0	0	0	0
Other than Temporary Impairment Losses, Investments		$ 0		$ 0