Equity-Method Investments Summarized Condensed Financial Information of LivingSocial (Detail) (LivingSocial, USD $) In Millions, unless otherwise specified	9 Months Ended				1 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Jan. 31, 2014 Korean operations
Statement of Operations:
Revenue	$ 215		$ 289
Gross profit	169		225
Operating expenses	261		283
Operating loss from continuing operations	(92)		(58)
Net loss from continuing operations	(75)		(50)
Net income (loss) from discontinued operations	206	[1]	(54)	[1]
Net income (loss)	131		(104)
LivingSocial sale of its Korean operations					260
Gain on disposal					$ 205

[1] In January 2014, LivingSocial completed the sale of its Korean operations for approximately $260 million and, in Q1 2014, recognized a gain on disposal of $205 million, net of tax. The statement of operations information above has been recast to present the Korean operations as discontinued operations.