Acquisitions - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Aug. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		$ 973	$ 842	$ 691
Equity Method Investments		$ 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		$ 88
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	Aug. 01, 2013
Business Combination, Consideration Transferred			6
Goodwill		77
Equity Method Investment, Ownership Percentage	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
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
Payless
Business Acquisition [Line Items]
Other intangibles, useful life, in years				15 years
Business Acquisition, Effective Date of Acquisition				Jul. 01, 2013
Business Combination, Consideration Transferred				$ 46
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles				23
Indefinite-Lived Trademarks				16
Goodwill				27
Payless | Licensing Agreements [Member]
Business Acquisition [Line Items]
Indefinite-Lived License Agreements				$ 7
Zipcar
Business Acquisition [Line Items]
Other intangibles, useful life, in years				8 years
Business Acquisition, Effective Date of Acquisition				Mar. 01, 2013
Business Combination, Consideration Transferred				$ 473
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles				188
Indefinite-Lived Trademarks				112
Goodwill				269
Zipcar | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-Lived Customer Relationships, Gross				$ 76