Accumulated Other Comprehensive Income (Loss) - Other Comprehensive Income (Loss) Before Reclassifications Associated With the Effective Portion of Derivatives Designated as Cash Flow Hedges (Detail) - Derivative Instruments [Member] - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax (expense) benefit	$ 1	$ 4	$ (8)
Net of tax	(2)	(7)	13
Foreign Currency Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) on derivatives before tax	$ (3)	$ (11)	$ 21