Equity-Method Investments - Summarized Condensed Financial Information of LivingSocial (Detail) (LivingSocial, USD $) In Millions, unless otherwise specified	6 Months Ended				1 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jan. 31, 2014 Korean operations
Statement of Operations:
Revenue	$ 152		$ 205
Gross profit	120		154
Operating expenses	174		199
Operating loss from continuing operations	(54)		(45)
Net loss from continuing operations	(39)		(42)
Net income (loss) from discontinued operations	204	[1]	(35)	[1]
Net income (loss)	165		(77)
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.