Acquisitions (Narrative) (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Goodwill	$ 964	$ 842
Maggiore Group [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Business Acquisition, Date of Acquisition Agreement	Apr. 01, 2015
Business Combination, Consideration Transferred	$ 160
Goodwill	$ 79
Other intangibles, useful life, in years	10 years
Brazil [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Business Acquisition, Date of Acquisition Agreement	Apr. 01, 2015
Equity Method Investment, Additional Information	0.5
Payments to Acquire Equity Method Investments	$ 8
Due to Related Parties	46
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Loss	8
Goodwill	$ 75
Scandinavian Licensee [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Business Acquisition, Date of Acquisition Agreement	Jan. 01, 2015
Business Combination, Consideration Transferred	$ 39
Goodwill	21
Non Cash Charge On Unfavorable License Rights Reacquired With Acquisition With Subsidiaries	22
Budget Licensees [Member]
Business Acquisition, Equity Interests Issued or Issuable [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
Customer Relationships [Member] | Maggiore Group [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Finite-lived Intangible Assets Acquired	51
Customer Relationships [Member] | Budget Licensees [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Other intangibles, useful life, in years		12 years
Finite-lived Intangible Assets Acquired		$ 10
Other Intangible Assets [Member] | Maggiore Group [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Finite-lived Intangible Assets Acquired	34
License Agreements [Member] | Maggiore Group [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Finite-lived Intangible Assets Acquired	$ 11
License Agreements [Member] | Scandinavian Licensee [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Other intangibles, useful life, in years	8 years
Finite-lived Intangible Assets Acquired	$ 31
License Agreements [Member] | Budget Licensees [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Other intangibles, useful life, in years		3 years
Finite-lived Intangible Assets Acquired		$ 48