Guarantor And Non-Guarantor Consolidating Condensed Financial Statements (Consolidating Condensed Statements Of Cash Flows) (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Supplemental Guarantor Financial Information [Line Items]
Net cash provided by (used in) operating activities	$ 1,931	$ 2,095
Property and equipment additions	(178)	(157)
Proceeds received on asset sales	7	9
Payments to Acquire Restricted Investments	(68)	(64)
Other, net	80	(44)
Net cash used in investing activities exclusive of vehicle programs	(159)	(256)
Investment in vehicles	(10,621)	(10,079)
Proceeds received on disposition of vehicles	7,826	6,752
Investment in debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	(221)	(116)
Proceeds from debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	137	22
Net cash used in investing activities of vehicle programs	(2,879)	(3,421)
Net cash used in investing activities	(3,038)	(3,677)
Proceeds from long-term borrowings	402	81
Principal payments on borrowings	(427)	(99)
Net change in short-term borrowings	0	(4)
Repurchases of common stock	(65)	(143)
Debt financing fees	(6)	(9)
Other, net	0	3
Net cash used in financing activities exclusive of vehicle programs	(96)	(171)
Proceeds from borrowings	16,042	13,371
Principal payments on borrowings	(14,838)	(11,727)
Debt financing fees	(18)	(19)
Net cash provided by financing activities of vehicle programs	1,186	1,625
Net cash provided by financing activities	1,090	1,454
Effect of changes in exchange rates on cash and cash equivalents, program and restricted cash	(10)	(5)
Net decrease in cash and cash equivalents, program and restricted cash	(27)	(133)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	708	768	$ 735	$ 901
Eliminations [Member]
Supplemental Guarantor Financial Information [Line Items]
Net cash provided by (used in) operating activities	(262)	(119)
Property and equipment additions	0	0
Proceeds received on asset sales	0	0
Payments to Acquire Restricted Investments	0	0
Other, net	75	0
Net cash used in investing activities exclusive of vehicle programs	75	0
Investment in vehicles	0	0
Proceeds received on disposition of vehicles	0	0
Investment in debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	0	0
Proceeds from debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	0	0
Net cash used in investing activities of vehicle programs	0	0
Net cash used in investing activities	75	0
Proceeds from long-term borrowings	0	0
Principal payments on borrowings	0	0
Net change in short-term borrowings		0
Repurchases of common stock	0	0
Debt financing fees	0	0
Other, net	187	119
Net cash used in financing activities exclusive of vehicle programs	187	119
Proceeds from borrowings	0	0
Principal payments on borrowings	0	0
Debt financing fees	0	0
Net cash provided by financing activities of vehicle programs	0	0
Net cash provided by financing activities	187	119
Effect of changes in exchange rates on cash and cash equivalents, program and restricted cash	0	0
Net decrease in cash and cash equivalents, program and restricted cash	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	0	0	0	0
Non-Guarantor Subsidiaries [Member]
Supplemental Guarantor Financial Information [Line Items]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	693	692
Parent Company [Member]
Supplemental Guarantor Financial Information [Line Items]
Net cash provided by (used in) operating activities	65	139
Property and equipment additions	0	0
Proceeds received on asset sales	0	0
Payments to Acquire Restricted Investments	0	0
Other, net	0	0
Net cash used in investing activities exclusive of vehicle programs	0	0
Investment in vehicles	0	0
Proceeds received on disposition of vehicles	0	0
Investment in debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	0	0
Proceeds from debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	0	0
Net cash used in investing activities of vehicle programs	0	0
Net cash used in investing activities	0	0
Proceeds from long-term borrowings	0	0
Principal payments on borrowings	0	0
Net change in short-term borrowings		0
Repurchases of common stock	(65)	(143)
Debt financing fees	0	0
Other, net	0	3
Net cash used in financing activities exclusive of vehicle programs	(65)	(140)
Proceeds from borrowings	0	0
Principal payments on borrowings	0	0
Debt financing fees	0	0
Net cash provided by financing activities of vehicle programs	0	0
Net cash provided by financing activities	(65)	(140)
Effect of changes in exchange rates on cash and cash equivalents, program and restricted cash	0	0
Net decrease in cash and cash equivalents, program and restricted cash	0	(1)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	1	3	1	4
Subsidiaries [Member]
Supplemental Guarantor Financial Information [Line Items]
Net cash provided by (used in) operating activities	196	202
Property and equipment additions	(56)	(45)
Proceeds received on asset sales	1	2
Payments to Acquire Restricted Investments	(5)	(3)
Other, net	(75)	(8)
Net cash used in investing activities exclusive of vehicle programs	(135)	(54)
Investment in vehicles	(42)	0
Proceeds received on disposition of vehicles	34	33
Investment in debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	0	0
Proceeds from debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	0	0
Net cash used in investing activities of vehicle programs	(8)	33
Net cash used in investing activities	(143)	(21)
Proceeds from long-term borrowings	400	81
Principal payments on borrowings	(420)	(97)
Net change in short-term borrowings		0
Repurchases of common stock	0	0
Debt financing fees	(6)	(9)
Other, net	(59)	(95)
Net cash used in financing activities exclusive of vehicle programs	(85)	(120)
Proceeds from borrowings	38	0
Principal payments on borrowings	(5)	(2)
Debt financing fees	0	0
Net cash provided by financing activities of vehicle programs	33	(2)
Net cash provided by financing activities	(52)	(122)
Effect of changes in exchange rates on cash and cash equivalents, program and restricted cash	0	0
Net decrease in cash and cash equivalents, program and restricted cash	1	59
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	13	73	12	14
Guarantor Subsidiaries [Member]
Supplemental Guarantor Financial Information [Line Items]
Net cash provided by (used in) operating activities	167	88
Property and equipment additions	(74)	(60)
Proceeds received on asset sales	0	2
Payments to Acquire Restricted Investments	(12)	(5)
Other, net	11	0
Net cash used in investing activities exclusive of vehicle programs	(75)	(63)
Investment in vehicles	(16)	(4)
Proceeds received on disposition of vehicles	0	0
Investment in debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	0	0
Proceeds from debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	0	0
Net cash used in investing activities of vehicle programs	(16)	(4)
Net cash used in investing activities	(91)	(67)
Proceeds from long-term borrowings	0	0
Principal payments on borrowings	(2)	(2)
Net change in short-term borrowings		0
Repurchases of common stock	0	0
Debt financing fees	0	0
Other, net	(64)	(12)
Net cash used in financing activities exclusive of vehicle programs	(66)	(14)
Proceeds from borrowings	0	0
Principal payments on borrowings	(10)	(7)
Debt financing fees	0	0
Net cash provided by financing activities of vehicle programs	(10)	(7)
Net cash provided by financing activities	(76)	(21)
Effect of changes in exchange rates on cash and cash equivalents, program and restricted cash	0	0
Net decrease in cash and cash equivalents, program and restricted cash	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	1	0	1	0
Subsidiaries Non Guarantor [Member]
Supplemental Guarantor Financial Information [Line Items]
Net cash provided by (used in) operating activities	1,765	1,785
Property and equipment additions	(48)	(52)
Proceeds received on asset sales	6	5
Payments to Acquire Restricted Investments	(51)	(56)
Other, net	69	(36)
Net cash used in investing activities exclusive of vehicle programs	(24)	(139)
Investment in vehicles	(10,563)	(10,075)
Proceeds received on disposition of vehicles	7,792	6,719
Investment in debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	(221)	(116)
Proceeds from debt securities of Avis Budget Rental Car Funding (AESOP) LLC—related party	137	22
Net cash used in investing activities of vehicle programs	(2,855)	(3,450)
Net cash used in investing activities	(2,879)	(3,589)
Proceeds from long-term borrowings	2	0
Principal payments on borrowings	(5)	0
Net change in short-term borrowings		(4)
Repurchases of common stock	0	0
Debt financing fees	0	0
Other, net	(64)	(12)
Net cash used in financing activities exclusive of vehicle programs	(67)	(16)
Proceeds from borrowings	16,004	13,371
Principal payments on borrowings	(14,823)	(11,718)
Debt financing fees	(18)	(19)
Net cash provided by financing activities of vehicle programs	1,163	1,634
Net cash provided by financing activities	1,096	1,618
Effect of changes in exchange rates on cash and cash equivalents, program and restricted cash	(10)	(5)
Net decrease in cash and cash equivalents, program and restricted cash	(28)	(191)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 693	$ 692	$ 721	$ 883