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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues
Vehicle rental	$ 1,871	$ 1,832	$ 4,772	$ 4,684
Other	785	745	2,008	1,916
Net revenues	2,656	2,577	6,780	6,600
Expenses
Operating	1,219	1,202	3,381	3,279
Vehicle depreciation and lease charges, net	576	555	1,571	1,485
Selling, general and administrative	315	314	896	843
Vehicle interest, net	77	75	215	218
Non-vehicle related depreciation and amortization	63	56	189	161
Interest expense	51	49	157	146
Intercompany interest expense (income)	0	0	0	0
Early extinguishment of debt	0	0	10	23
Restructuring expense	6	6	26	10
Transaction-related costs, net	4	8	13	57
Total expenses	2,311	2,265	6,458	6,222
Income before income taxes	345	312	322	378
Provision for (benefit from) income taxes	(136)	(128)	(128)	(60)
Equity in earnings (loss) of subsidiaries	0	0	0	0
Net income (loss)	209	184	194	318
Comprehensive income (loss)	(235)	(150)	(294)	(198)
Parent Company [Member]
Revenues
Vehicle rental	0	0	0	0
Other	0	0	0	0
Net revenues	0	0	0	0
Expenses
Operating	1	0	3	1
Vehicle depreciation and lease charges, net	0	0	0	0
Selling, general and administrative	10	7	29	24
Vehicle interest, net	0	0	0	0
Non-vehicle related depreciation and amortization	0	0	0	0
Interest expense	0	0	0	0
Intercompany interest expense (income)	(3)	(3)	(9)	(9)
Early extinguishment of debt			0	0
Restructuring expense	0	0	0	0
Transaction-related costs, net	0	0	0	0
Total expenses	8	4	23	16
Income before income taxes	(8)	(4)	(23)	(16)
Provision for (benefit from) income taxes	3	1	9	6
Equity in earnings (loss) of subsidiaries	214	187	208	328
Net income (loss)	209	184	194	318
Comprehensive income (loss)	(235)	(150)	(294)	(198)
Subsidiary Issuers [Member]
Revenues
Vehicle rental	0	0	0	0
Other	0	0	0	0
Net revenues	0	0	0	0
Expenses
Operating	3	3	14	12
Vehicle depreciation and lease charges, net	0	1	0	1
Selling, general and administrative	4	5	14	11
Vehicle interest, net	0	0	0	0
Non-vehicle related depreciation and amortization	0	0	1	1
Interest expense	41	39	122	121
Intercompany interest expense (income)	(3)	(3)	(8)	(8)
Early extinguishment of debt			10	23
Restructuring expense	0	0	0	0
Transaction-related costs, net	0	2	1	20
Total expenses	45	47	154	181
Income before income taxes	(45)	(47)	(154)	(181)
Provision for (benefit from) income taxes	18	18	61	165
Equity in earnings (loss) of subsidiaries	241	216	301	344
Net income (loss)	214	187	208	328
Comprehensive income (loss)	(239)	(155)	(307)	(210)
Guarantor Subsidiaries [Member]
Revenues
Vehicle rental	1,216	1,196	3,229	3,193
Other	344	336	931	910
Net revenues	1,560	1,532	4,160	4,103
Expenses
Operating	719	716	2,013	1,978
Vehicle depreciation and lease charges, net	525	485	1,514	1,397
Selling, general and administrative	173	175	492	477
Vehicle interest, net	55	53	149	154
Non-vehicle related depreciation and amortization	38	33	115	99
Interest expense	1	1	3	(6)
Intercompany interest expense (income)	6	5	17	11
Early extinguishment of debt			0	0
Restructuring expense	1	4	8	5
Transaction-related costs, net	0	2	1	3
Total expenses	1,518	1,474	4,312	4,118
Income before income taxes	42	58	(152)	(15)
Provision for (benefit from) income taxes	(87)	(101)	(119)	(162)
Equity in earnings (loss) of subsidiaries	286	259	572	521
Net income (loss)	241	216	301	344
Comprehensive income (loss)	(262)	(186)	(403)	(230)
Non-Guarantor Subsidiaries [Member]
Revenues
Vehicle rental	655	636	1,543	1,491
Other	1,021	951	2,746	2,570
Net revenues	1,676	1,587	4,289	4,061
Expenses
Operating	496	483	1,351	1,288
Vehicle depreciation and lease charges, net	575	556	1,571	1,487
Selling, general and administrative	128	127	361	331
Vehicle interest, net	78	77	221	228
Non-vehicle related depreciation and amortization	25	23	73	61
Interest expense	9	9	32	31
Intercompany interest expense (income)	0	1	0	6
Early extinguishment of debt			0	0
Restructuring expense	5	2	18	5
Transaction-related costs, net	4	4	11	34
Total expenses	1,320	1,282	3,638	3,471
Income before income taxes	356	305	651	590
Provision for (benefit from) income taxes	(70)	(46)	(79)	(69)
Equity in earnings (loss) of subsidiaries	0	0	0	0
Net income (loss)	286	259	572	521
Comprehensive income (loss)	(307)	(228)	(672)	(406)
Eliminations [Member]
Revenues
Vehicle rental	0	0	0	0
Other	(580)	(542)	(1,669)	(1,564)
Net revenues	(580)	(542)	(1,669)	(1,564)
Expenses
Operating	0	0	0	0
Vehicle depreciation and lease charges, net	(524)	(487)	(1,514)	(1,400)
Selling, general and administrative	0	0	0	0
Vehicle interest, net	(56)	(55)	(155)	(164)
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
Restructuring expense	0	0	0	0
Transaction-related costs, net	0	0	0	0
Total expenses	(580)	(542)	(1,669)	(1,564)
Income before income taxes	0	0	0	0
Provision for (benefit from) income taxes	0	0	0	0
Equity in earnings (loss) of subsidiaries	(741)	(662)	(1,081)	(1,193)
Net income (loss)	(741)	(662)	(1,081)	(1,193)
Comprehensive income (loss)	$ 808	$ 569	$ 1,382	$ 846