CONSOLIDATED CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	Cumulative effect of accounting change	Stockholders’ Equity Attributable to Avis Budget Group, Inc.	Stockholders’ Equity Attributable to Avis Budget Group, Inc. Cumulative effect of accounting change	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Deficit Cumulative effect of accounting change	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Non-controlling Interests
Beginning balance (in shares) at Dec. 31, 2019					137.1					(63.2)
Beginning balance at Dec. 31, 2019	$ 656	$ (1)	$ 656	$ (1)	$ 1	$ 6,741	$ (785)	$ (1)	$ (157)	$ (5,144)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(594)		(594)				(594)
Other comprehensive income (loss)	(37)		(37)						(37)
Total comprehensive income (loss)	(631)		(631)				(594)		(37)
Contributions from non-controlling interests	2					2
Net activity related to restricted stock units (in shares)										0.4
Net activity related to restricted stock units	0					(82)				$ 82
Issuance of common stock (in shares)										0.4
Issuance of common stock	15		15			15
Repurchases of common stock (in shares)										(5.0)
Repurchases of common stock	(113)		(113)							$ (113)
Ending balance (in shares) at Sep. 30, 2020					137.1					(67.4)
Ending balance at Sep. 30, 2020	(76)		(76)		$ 1	6,672	(1,380)		(194)	$ (5,175)	0
Beginning balance (in shares) at Jun. 30, 2020					137.1					(67.4)
Beginning balance at Jun. 30, 2020	(153)		(153)		$ 1	6,670	(1,425)		(223)	$ (5,176)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	45		45				45
Other comprehensive income (loss)	29		29						29
Total comprehensive income (loss)	74		74				45		29
Contributions from non-controlling interests			2
Net activity related to restricted stock units	3		3			2				$ 1
Ending balance (in shares) at Sep. 30, 2020					137.1					(67.4)
Ending balance at Sep. 30, 2020	(76)		(76)		$ 1	6,672	(1,380)		(194)	$ (5,175)	0
Beginning balance (in shares) at Dec. 31, 2020					137.1					(67.3)
Beginning balance at Dec. 31, 2020	(155)		(155)		$ 1	6,668	(1,470)		(187)	$ (5,167)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	902		903				903				(1)
Other comprehensive income (loss)	11		11						11
Total comprehensive income (loss)	$ 913		914				903		11		(1)
Contributions from non-controlling interests			24			24					14
Net activity related to restricted stock units (in shares)	11.7									0.3
Net activity related to restricted stock units	$ 10		10			(19)				$ 29
Repurchases of common stock (in shares)										(11.7)
Repurchases of common stock	(1,004)		(1,004)							$ (1,004)
Ending balance (in shares) at Sep. 30, 2021					137.1					(78.7)
Ending balance at Sep. 30, 2021	(198)		(211)		$ 1	6,673	(567)		(176)	$ (6,142)	13
Beginning balance (in shares) at Jun. 30, 2021					137.1					(67.1)
Beginning balance at Jun. 30, 2021	92		92		$ 1	6,646	(1,242)		(161)	$ (5,152)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	674		675				675				(1)
Other comprehensive income (loss)	(15)		(15)						(15)
Total comprehensive income (loss)	659		660				675		(15)		(1)
Contributions from non-controlling interests	38		24			(24)					14
Net activity related to restricted stock units	7		7			3				$ 4
Repurchases of common stock (in shares)										(11.6)
Repurchases of common stock	(994)		(994)							$ (994)
Ending balance (in shares) at Sep. 30, 2021					137.1					(78.7)
Ending balance at Sep. 30, 2021	$ (198)		$ (211)		$ 1	$ 6,673	$ (567)		$ (176)	$ (6,142)	$ 13