Acquisitions (Details) - USD ($) $ in Millions	1 Months Ended			12 Months Ended
	Oct. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 10		$ 14	$ 23
Goodwill				1,108	$ 1,099	$ 1,070
McNicoll Vehicle Hire
Business Acquisition [Line Items]
Business combination, consideration transferred		$ 17
Goodwill		10
Franchise Rights
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			$ 14	$ 28
Acquired finite-lived intangible assets, weighted average useful life			5 years	1 year
Trade Names | McNicoll Vehicle Hire
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		$ 4
Acquired finite-lived intangible assets, weighted average useful life		10 years
Customer relationships | McNicoll Vehicle Hire
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		$ 1
Acquired finite-lived intangible assets, weighted average useful life		10 years
License agreements
Business Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 10
Acquired finite-lived intangible assets, weighted average useful life	3 years
Vehicle leases
Business Acquisition [Line Items]
Property and equipment additions	$ 4		$ 20	$ 22