Segment Information (Summary Of Segments Information) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Revenues	$ 3,244	$ 2,371	$ 5,676	$ 3,743
Adjusted EBITDA	1,205	624	2,015	671
Less:
Non-vehicle related depreciation and amortization	53	67	113	135
Interest expense	64	59	117	120
Early extinguishment of debt	0	0	0	129
Restructuring and other related charges	6	22	14	42
Unprecedented personal-injury and other legal matters, net	0	(11)	1	(11)
Transaction-related costs, net	1	1	1	2
COVID-19 charges	(2)	0	(9)	18
Net income	1,083	486	1,778	236
Minimum annual guaranteed rent in excess of concession fees, net	(2)	(3)	(9)	16
Vehicles damaged in overflow parking lots, net of insurance proceeds	0	2	0	(4)
Other charges	0	1	0	6
COVID-19 charges	(2)	0	(9)	18
Statements of Operations | Cloud Based Computing Costs
Less:
COVID-19 charges	2		4
COVID-19 charges	2		4
Operating expense
Less:
Non-vehicle related depreciation and amortization		3		3
COVID-19 charges	(2)	0	(9)	17
COVID-19 charges	(2)	0	(9)	17
Selling, general and administrative expenses
Less:
Non-vehicle related depreciation and amortization		2		2
COVID-19 charges			0	1
COVID-19 charges			0	1
COVID-19 Charges
Less:
COVID-19 charges	(2)	0	(9)	18
COVID-19 charges	(2)	0	(9)	18
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Adjusted EBITDA	(19)	(18)	(42)	(29)
Americas | Geographical
Segment Reporting Information [Line Items]
Revenues	2,567	1,974	4,567	3,054
Adjusted EBITDA	1,041	634	1,851	742
International | Geographical
Segment Reporting Information [Line Items]
Revenues	677	397	1,109	689
Adjusted EBITDA	$ 183	$ 8	$ 206	$ (42)