Earnings Per Share (Computation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net income attributable to Avis Budget Group, Inc. for basic and diluted EPS	$ 626	$ 1,034	$ 1,373	$ 2,341
Basic weighted average shares outstanding (in shares)	36.9	46.8	39.1	49.5
Non-vested stock (in shares)	0.4	0.9	0.4	1.1
Diluted weighted average shares outstanding (in shares)	37.3	47.7	39.5	50.6
Earnings per share:
Basic (in usd per share)	$ 16.96	$ 22.08	$ 35.11	$ 47.34
Diluted (in usd per share)	$ 16.78	$ 21.67	$ 34.71	$ 46.32
Non-vested stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	0.0	0.1	0.1	0.1