Acquisitions - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended			12 Months Ended
	Dec. 31, 2016	Apr. 30, 2015	Aug. 31, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 1,007			$ 1,007	$ 973	$ 842
Equity Method Investments	$ 0			$ 0	$ 0
Maggiore Group [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Apr. 01, 2015
Business Combination, Consideration Transferred		$ 160
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life					10 years
Goodwill					$ 82
Maggiore Group [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired					34
Maggiore Group [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired					50
Maggiore Group [Member] | Licensing Agreements [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired					11
Brazil [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Apr. 01, 2015	Aug. 01, 2013
Business Combination, Consideration Transferred						6
Goodwill					77
Equity Method Investment, Ownership Percentage		50.00%	50.00%
Payments to Acquire Equity Method Investments			$ 53		8		$ 47
Due to Related Parties					46
Equity Method Investments						12
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net						33
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Loss					8
France Cars [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Dec. 01, 2016
Business Combination, Consideration Transferred	$ 45
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life				16 years
Goodwill	$ 23			$ 23
France Cars [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired				9
France Cars [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired				$ 6
Avis and Budget Licensees [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred					62
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities					$ 23
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life					8 years
Goodwill					$ 29
Non Cash Charge On Unfavorable License Rights Reacquired With Acquisition With Subsidiaries					25
Avis and Budget Licensees [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired					12
Avis and Budget Licensees [Member] | Licensing Agreements [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired					$ 36
Budget Licensees [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred						263
Business Acquisition Purchase Price Allocation Vehicles Net						132
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill						58
Goodwill						192
Non Cash Charge On Unfavorable License Rights Reacquired With Acquisition With Subsidiaries						20
Budget Licensees [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired						$ 10
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						12 years
Budget Licensees [Member] | Licensing Agreements [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired						$ 48
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						3 years