Accumulated Other Comprehensive Income - Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning balance			$ 23
Other comprehensive income (loss) before reclassifications, net of tax			(102)
Amounts reclassified from accumulated other comprehensive (income) loss, net of tax			(12)
Other comprehensive income (loss), net of taxes	$ (57)	$ (58)	(114)	$ (77)
Accumulated Other Comprehensive Income (Loss), Ending balance	(91)		(91)
Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning balance			(61)
Other comprehensive income (loss) before reclassifications, net of tax			27
Amounts reclassified from accumulated other comprehensive (income) loss, net of tax			(17)
Other comprehensive income (loss), net of taxes			10
Accumulated Other Comprehensive Income (Loss), Ending balance	(51)		(51)
Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning balance			10
Other comprehensive income (loss) before reclassifications, net of tax			(1)
Other comprehensive income (loss), net of taxes			(1)
Accumulated Other Comprehensive Income (Loss), Ending balance	9		9
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning balance			84
Other comprehensive income (loss) before reclassifications, net of tax			(128)
Amounts reclassified from accumulated other comprehensive (income) loss, net of tax			5
Other comprehensive income (loss), net of taxes			(123)
Accumulated Other Comprehensive Income (Loss), Ending balance	(39)		(39)
Post - Retirement Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning balance			$ (10)
Other comprehensive income (loss) before reclassifications, net of tax
Accumulated Other Comprehensive Income (Loss), Ending balance	$ (10)		$ (10)