Unrecognized Tax Benefits Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Unrecognized tax benefits, non-current income taxes payable	$ 57	$ 41
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	27	29
Unrecognized Tax Benefits	54	$ 61	$ 63	$ 59
Non Avis Budget Car Rental Tax Contingencies
Income Taxes [Line Items]
Unrecognized Tax Benefits	$ 13