Guarantor And Non-Guarantor Consolidating Condensed Financial Statements (Consolidating Condensed Statements Of Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues
Vehicle rental	$ 1,563	$ 1,573	$ 2,849	$ 2,901
Other	675	670	1,228	1,223
Net revenues	2,238	2,243	4,077	4,124
Expenses
Operating	1,108	1,122	2,157	2,162
Vehicle depreciation and lease charges, net	597	532	1,101	995
Selling, general and administrative	293	312	555	581
Vehicle interest, net	73	73	137	138
Non-vehicle related depreciation and amortization	65	65	128	126
Interest expense	48	56	97	106
Intercompany interest expense (income)	0	0	0	0
Early extinguishment of debt	0	10	3	10
Restructuring and other related charges	38	5	45	20
Transaction-related costs, net	5	5	8	9
Total expenses	2,227	2,180	4,231	4,147
Income before income taxes	11	63	(154)	(23)
Provision for (benefit from) income taxes	(8)	(27)	50	8
Equity in earnings (loss) of subsidiaries	0	0	0	0
Net income (loss)	3	36	(104)	(15)
Comprehensive income (loss)	(51)	(40)	28	(59)
Eliminations [Member]
Revenues
Vehicle rental	0	0	0	0
Other	(663)	(577)	(1,248)	(1,089)
Net revenues	(663)	(577)	(1,248)	(1,089)
Expenses
Operating	0	0	0	0
Vehicle depreciation and lease charges, net	(609)	(525)	(1,144)	(990)
Selling, general and administrative	0	0	0	0
Vehicle interest, net	(54)	(52)	(104)	(99)
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	0	0
Restructuring and other related charges	0	0	0	0
Transaction-related costs, net	0	0	0	0
Total expenses	(663)	(577)	(1,248)	(1,089)
Income before income taxes	0	0	0	0
Provision for (benefit from) income taxes	0	0	0	0
Equity in earnings (loss) of subsidiaries	(341)	(286)	(349)	(340)
Net income (loss)	(341)	(286)	(349)	(340)
Comprehensive income (loss)	490	307	578	574
Parent Company [Member]
Revenues
Vehicle rental	0	0	0	0
Other	0	0	0	0
Net revenues	0	0	0	0
Expenses
Operating	1	1	2	2
Vehicle depreciation and lease charges, net	0	0	0	0
Selling, general and administrative	10	9	20	19
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)	(6)	(6)
Early extinguishment of debt	0	0	0	0
Restructuring and other related charges	0	0	0	0
Transaction-related costs, net	0	0	0	0
Total expenses	8	7	16	15
Income before income taxes	(8)	(7)	(16)	(15)
Provision for (benefit from) income taxes	2	3	4	6
Equity in earnings (loss) of subsidiaries	9	40	(92)	(6)
Net income (loss)	3	36	(104)	(15)
Comprehensive income (loss)	(51)	(40)	28	(59)
Subsidiaries [Member]
Revenues
Vehicle rental	0	0	0	0
Other	0	0	0	0
Net revenues	0	0	0	0
Expenses
Operating	9	1	13	11
Vehicle depreciation and lease charges, net	0	0	0	0
Selling, general and administrative	2	5	4	10
Vehicle interest, net	0	0	0	0
Non-vehicle related depreciation and amortization	1	0	1	1
Interest expense	83	42	129	81
Intercompany interest expense (income)	5	(2)	6	(5)
Early extinguishment of debt	1	10	4	10
Restructuring and other related charges	2	0	2	0
Transaction-related costs, net	0	0	0	1
Total expenses	103	56	159	109
Income before income taxes	(103)	(56)	(159)	(109)
Provision for (benefit from) income taxes	39	22	62	43
Equity in earnings (loss) of subsidiaries	73	74	5	60
Net income (loss)	9	40	(92)	(6)
Comprehensive income (loss)	(58)	(44)	16	(68)
Guarantor Subsidiaries [Member]
Revenues
Vehicle rental	1,055	1,084	1,941	2,013
Other	316	316	583	587
Net revenues	1,371	1,400	2,524	2,600
Expenses
Operating	644	666	1,284	1,294
Vehicle depreciation and lease charges, net	614	528	1,160	989
Selling, general and administrative	158	170	311	319
Vehicle interest, net	52	49	97	94
Non-vehicle related depreciation and amortization	40	40	80	77
Interest expense	0	1	1	2
Intercompany interest expense (income)	5	5	11	11
Early extinguishment of debt	0	0	0	0
Restructuring and other related charges	33	1	39	7
Transaction-related costs, net	0	1	0	1
Total expenses	1,546	1,461	2,983	2,794
Income before income taxes	(175)	(61)	(459)	(194)
Provision for (benefit from) income taxes	(11)	(37)	28	(32)
Equity in earnings (loss) of subsidiaries	259	172	436	286
Net income (loss)	73	74	5	60
Comprehensive income (loss)	(123)	(83)	(82)	(141)
Non-Guarantor Subsidiaries [Member]
Revenues
Vehicle rental	508	489	908	888
Other	1,022	931	1,893	1,725
Net revenues	1,530	1,420	2,801	2,613
Expenses
Operating	454	454	858	855
Vehicle depreciation and lease charges, net	592	529	1,085	996
Selling, general and administrative	123	128	220	233
Vehicle interest, net	75	76	144	143
Non-vehicle related depreciation and amortization	24	25	47	48
Interest expense	(35)	13	(33)	23
Intercompany interest expense (income)	(7)	0	(11)	0
Early extinguishment of debt	(1)	0	(1)	0
Restructuring and other related charges	3	4	4	13
Transaction-related costs, net	5	4	8	7
Total expenses	1,233	1,233	2,321	2,318
Income before income taxes	297	187	480	295
Provision for (benefit from) income taxes	(38)	(15)	(44)	(9)
Equity in earnings (loss) of subsidiaries	0	0	0	0
Net income (loss)	259	172	436	286
Comprehensive income (loss)	$ (309)	$ (180)	$ (512)	$ (365)