Stockholders' Equity (Components of Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Equity [Abstract]
Net loss	$ (504)	$ (113)
Less: Net income attributable to non-controlling interests	1	1
Net loss attributable to Avis Budget Group, Inc.	(505)	(114)
Other comprehensive income (loss), net of tax
Currency translation adjustments, net of tax of $0 and $(5), respectively	13	(52)
Net unrealized gain (loss) on cash flow hedges, net of tax of $3 and $(2), respectively	(6)	7
Minimum pension liability adjustment, net of tax of $0, in each period	1	1
Net current-period other comprehensive income (loss)	8	(44)
Total comprehensive loss attributable to Avis Budget Group, Inc.	(497)	(158)
Currency translation adjustments, tax	14	(5)
Net unrealized gain (loss) on cash flow hedges, tax	3	(2)
Minimum pension liability adjustment, tax	$ 0	$ 0