Segment Information (Schedule of Segments Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Revenues	$ 2,430	$ 2,551
Significant segment expenses:
Operating	1,353	1,344
Vehicle depreciation and lease charges, net	1,055	636
Selling, general and administrative	308	325
Vehicle interest, net	210	239
Reconciliation of reportable segment Adjusted EBITDA to loss before income taxes:
Non-vehicle related depreciation and amortization	56	61
Other fleet charges	390
Restructuring and other related charges	22	3
Transaction-related costs, net	0	1
Other (income) expense, net	6	1
Loss before income taxes	(677)	(142)
Operating Segments
Segment Reporting Information [Line Items]
Revenues	2,430	2,551
Significant segment expenses:
Reportable segment Adjusted EBITDA	(70)	29
Reconciliation of reportable segment Adjusted EBITDA to loss before income taxes:
Non-vehicle related depreciation and amortization	55	57
Interest expense	2	2
Other fleet charges	390
Restructuring and other related charges	22	3
Transaction-related costs, net		1
Other (income) expense, net	6	1
Cloud computing costs	1	(3)
Operating Segments | Americas
Segment Reporting Information [Line Items]
Revenues	1,907	1,993
Significant segment expenses:
Operating	1,064	1,052
Vehicle depreciation and lease charges, net	533	487
Selling, general and administrative	200	207
Vehicle interest, net	177	203
Reportable segment Adjusted EBITDA	(67)	44
Operating Segments | International
Segment Reporting Information [Line Items]
Revenues	523	558
Significant segment expenses:
Operating	274	289
Vehicle depreciation and lease charges, net	132	149
Selling, general and administrative	87	99
Vehicle interest, net	33	36
Reportable segment Adjusted EBITDA	(3)	(15)
Corporate and Other
Reconciliation of reportable segment Adjusted EBITDA to loss before income taxes:
Corporate and other	131	110
Interest expense related to corporate debt, net	$ 95	$ 81