Restatement (Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended			48 Months Ended	60 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2013
Revenues:
Worldwide car rental	$ 2,000	$ 2,563	$ 2,304	$ 2,039	$ 2,019	$ 2,538	$ 2,197	$ 1,955	$ 4,343	$ 4,153	$ 6,907	$ 6,690	$ 8,907	$ 8,709	$ 7,153
Worldwide equipment rental	416	413	384	358	401	403	381	353	743	734	1,155	1,138	1,571	1,539	1,382
All other operations	143	145	142	139	135	134	130	129	280	258	425	392	568	527	478
Revenues	2,559	3,121	2,830	2,536	2,555	3,075	2,708	2,437	5,366	5,145	8,487	8,220	11,046	10,775	9,013
Expenses:
Direct operating	1,575	1,702	1,594	1,443	1,449	1,547	1,417	1,364	3,037	2,781	4,738	4,328	6,314	5,777	4,861
Depreciation of revenue earning equipment and lease charges, net	853	746	708	726	641	672	632	589	1,434	1,220	2,180	1,893	3,034	2,533	2,128
Selling, general and administrative	246	303	265	276	234	282	287	250	541	538	844	819	1,088	1,053	978
Interest expense, net	163	163	162	153	168	173	168	161	315	329	479	502	641	669	596
Other (income) expense, net	6	3	(22)	(3)	21	44	(2)	0	(25)	(2)	(22)	42	(15)	64	33
Total expenses	2,843	2,917	2,707	2,595	2,513	2,718	2,502	2,364	5,302	4,866	8,219	7,584	11,062	10,096	8,596
Total	(284)	204	123	(59)	42	357	206	73	64	279	268	636	(16)	679	417
(Provision) benefit for taxes on income (loss)	50	(54)	(50)	(8)	(56)	(128)	(86)	(59)	(58)	(145)	(112)	(272)	(62)	(329)	(200)
Net income (loss)	$ (234)	$ 150	$ 73	$ (67)	(14)	229	120	14	$ 6	134	$ 156	364	$ (78)	350	217
As Previously Reported
Revenues:
Worldwide car rental					2,020	2,534	2,195	1,957		4,152		6,686		8,707	7,162
Worldwide equipment rental					401	402	384	351		735		1,137		1,538	1,385
All other operations					135	134	130	129		259		392		527	478
Revenues					2,556	3,070	2,709	2,437		5,146		8,215		10,772	9,025
Expenses:
Direct operating					1,439	1,540	1,414	1,358		2,773		4,313		5,752	4,806
Depreciation of revenue earning equipment and lease charges, net					643	675	628	580		1,208		1,882		2,526	2,129
Selling, general and administrative					222	272	280	248		529		800		1,022	968
Interest expense, net					166	173	168	161		329		501		666	594
Other (income) expense, net					21	44	(1)	2		0		45		67	35
Total expenses					2,491	2,704	2,489	2,349		4,839		7,541		10,033	8,532
Total					65	366	220	88		307		674		739	493
(Provision) benefit for taxes on income (loss)					(62)	(129)	(90)	(64)		(153)		(283)		(345)	(221)
Net income (loss)					3	237	130	24		154		391		394	272
Restatement Adjustment
Revenues:
Worldwide car rental					(1)	4	2	(2)		1		4		2	(9)
Worldwide equipment rental					0	1	(3)	2		(1)		1		1	(3)
All other operations					0	0	0	0		(1)		0		0	0
Revenues					(1)	5	(1)	0		(1)		5		3	(12)
Expenses:
Direct operating					10	7	3	6		8		15		25	55
Depreciation of revenue earning equipment and lease charges, net					(2)	(3)	4	9		12		11		7	(1)
Selling, general and administrative					12	10	7	2		9		19		31	10
Interest expense, net					2	0	0	0		0		1		3	2
Other (income) expense, net					0	0	(1)	(2)		(2)		(3)		(3)	(2)
Total expenses					22	14	13	15		27		43		63	64
Total					(23)	(9)	(14)	(15)		(28)		(38)		(60)	(76)	$ 35	$ 46
(Provision) benefit for taxes on income (loss)					6	1	4	5		8		11		16	21
Net income (loss)					$ (17)	$ (8)	$ (10)	$ (10)		$ (20)		$ (27)		$ (44)	$ (55)	$ 21