Stockholders' Equity - Schedule of Components of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net loss	$ (234)	$ (504)
Less: Net income attributable to non-controlling interests	49	1
Net loss attributable to Avis Budget Group, Inc.	(283)	(505)
Other comprehensive income (loss), net of tax
Currency translation adjustments, net of tax of $(6) and $14, respectively	6	13
Net unrealized gain (loss) on cash flow hedges, net of tax of $1 and $3, respectively	(1)	(6)
Minimum pension liability adjustment, net of tax of $0, in each period	3	(1)
Net current-period other comprehensive income (loss)	2	8
Total comprehensive loss attributable to Avis Budget Group, Inc.	(281)	(497)
Currency translation adjustments, tax	(6)	14
Net unrealized gain (loss) on cash flow hedges, tax	1	3
Minimum pension liability adjustment, tax	0	0
Stockholders’ Equity Attributable to Avis Budget Group, Inc.
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net loss		$ (505)
Other comprehensive income (loss), net of tax
Total comprehensive loss attributable to Avis Budget Group, Inc.	$ (281)