Segment Information - Summary of Segments Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 9,313	$ 5,402	$ 9,172
Vehicle depreciation and lease charges, net	1,197	1,368	2,063
Vehicle interest, net	313	318	344
Adjusted EBITDA	2,411	(175)	788
Non-vehicle depreciation and amortization	272	286	263
Assets exclusive of assets under vehicle programs	8,581	8,365	9,311
Assets under vehicle programs	14,019	9,173	13,815
Capital expenditures (excluding vehicles)	108	94	250
Americas
Segment Reporting Information [Line Items]
Revenues	7,557	3,965	6,352
Vehicle depreciation and lease charges, net	851	968	1,462
Vehicle interest, net	258	274	284
Adjusted EBITDA	2,364	72	652
Non-vehicle depreciation and amortization	178	185	161
Assets exclusive of assets under vehicle programs	5,746	5,510	6,226
Assets under vehicle programs	11,437	7,155	10,508
Capital expenditures (excluding vehicles)	74	65	162
International
Segment Reporting Information [Line Items]
Revenues	1,756	1,437	2,820
Vehicle depreciation and lease charges, net	346	400	601
Vehicle interest, net	55	44	60
Adjusted EBITDA	118	(202)	203
Non-vehicle depreciation and amortization	84	91	94
Assets exclusive of assets under vehicle programs	2,716	2,754	2,995
Assets under vehicle programs	2,582	2,018	3,307
Capital expenditures (excluding vehicles)	26	29	62
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	0	0	0
Vehicle depreciation and lease charges, net	0	0	0
Vehicle interest, net	0	0	0
Adjusted EBITDA	(71)	(45)	(67)
Non-vehicle depreciation and amortization	10	10	8
Assets exclusive of assets under vehicle programs	119	101	90
Assets under vehicle programs	0	0	0
Capital expenditures (excluding vehicles)	$ 8	$ 0	$ 26