Accumulated Other Comprehensive Loss - Reclassification (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net				$ (53)
Income before income taxes	$ 603	$ 457	$ 1,607	1,312
Tax (expense) benefit	(215)	(153)	(561)	(466)
Consolidated net income	388	304	1,046	846
Derivative Instrument [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(3)	(3)	(9)	(29)
Tax (expense) benefit	1	1	3	11
Consolidated net income	(2)	(2)	(6)	(18)
Derivative Instrument [Member] | Interest Rate Swaps [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net	(2)	(2)	(8)	(8)
Derivative Instrument [Member] | Treasury Lock [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net	$ (1)	$ (1)	$ (1)	(1)
Derivative Instrument [Member] | Foreign Currency Derivatives [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net				$ (20)