Leases - Lessor (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total lease revenues	$ 9,186	$ 5,243	$ 9,028
Avis
Disaggregation of Revenue [Line Items]
Total lease revenues	4,828	2,851	5,163
Budget
Disaggregation of Revenue [Line Items]
Total lease revenues	3,674	1,878	3,129
Other
Disaggregation of Revenue [Line Items]
Total lease revenues	684	514	736
Americas
Disaggregation of Revenue [Line Items]
Total lease revenues	7,501	3,864	6,303
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total lease revenues	1,343	1,080	2,141
Asia and Australasia
Disaggregation of Revenue [Line Items]
Total lease revenues	$ 342	$ 299	$ 584