Acquisitions - Additional Information (Detail) € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 EUR (€)	Dec. 31, 2017 USD ($)
Business Acquisition [Line Items]
Goodwill	$ 1,101	$ 1,092		$ 1,073
2019 Avis and Budget Licensees [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	55
Business Acquisition Purchase Price Allocation Vehicles, Net	27
Business Combination, Contingent Consideration, Liability	8
Payments to Acquire Businesses, Gross	$ 74
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Goodwill	$ 21
2019 Avis and Budget Licensees [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	7
2019 Avis and Budget Licensees [Member] | Licensing Agreements [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 24
2018 Avis and Budget Licensees [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 38
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		2 years
2018 Avis and Budget Licensees [Member] | Licensing Agreements [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		$ 42
Turiscar Group [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		25
Business Combination, Contingent Consideration, Liability | €			€ 4
Payments to Acquire Businesses, Gross		$ 26
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		11 years
Goodwill		$ 12
Turiscar Group [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		10
Turiscar Group [Member] | Trademarks
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		2
Morini S.p.A. [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		40
Business Combination, Contingent Consideration, Liability		6	€ 7
Payments to Acquire Businesses, Gross		$ 32
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		6 years
Goodwill		$ 42
Morini S.p.A. [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		6
Morini S.p.A. [Member] | Trademarks
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		3
Morini S.p.A. [Member] | Licensing Agreements [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		$ 2