Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net income (loss) attributable to Avis Budget Group, Inc.	$ 1,285	$ (684)	$ 302
Basic weighted average shares outstanding (in shares)	64.9	70.5	75.2
Options and non-vested stock (in shares)	1.2	0.0	0.5
Diluted weighted average shares outstanding (in shares)	66.1	70.5	75.7
Earnings (loss) per share:
Basic (in USD per share)	$ 19.79	$ (9.71)	$ 4.01
Diluted (in USD per share)	$ 19.44	$ (9.71)	$ 3.98