Segment Information (Summary Of Segments Information) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Revenues	$ 2,557	$ 2,432
Adjusted EBITDA	535	810
Less:
Non-vehicle related depreciation and amortization	56	58
Interest expense	73	53
Restructuring and other related charges	4	8
Other (income) expense, net	(2)	0
COVID-19 charges	0	(7)
Unprecedented personal-injury and other legal matters, net	0	1
Net income	397	695
Operating Expense | Cloud Computing Costs
Less:
Cloud computing costs	7	2
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	0	0
Adjusted EBITDA	(31)	(23)
Americas | Geographical
Segment Reporting Information [Line Items]
Revenues	2,016	2,000
Adjusted EBITDA	516	810
International | Geographical
Segment Reporting Information [Line Items]
Revenues	541	432
Adjusted EBITDA	$ 50	$ 23