Equity-Method Investments - Summarized Condensed Financial Information of LivingSocial (Detail) (LivingSocial, USD $) In Millions, unless otherwise specified	3 Months Ended				1 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Jan. 31, 2014 Korean operations
Statement of Operations:
Revenue	$ 77		$ 108
Gross profit	62		82
Operating expenses	98		107
Operating loss from continuing operations	(36)		(25)
Net loss from continuing operations	(26)		(26)
Net income (loss) from discontinued operations	203	[1]	(19)	[1]
Net income (loss)	177		(45)
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 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.