Comprehensive Income - Summary of Components of AOCI (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 8,633
Ending Balance	7,264
Beginning Balance	22
Other comprehensive income (loss) before reclassifications	140
Ending Balance	162
Other comprehensive income (loss) before reclassifications	491
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(623)
Other comprehensive income (loss) before reclassifications	353
Ending Balance	(270)
Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	10
Other comprehensive income (loss) before reclassifications	(2)
Ending Balance	8
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	21
Ending Balance	21
Accumulated Other Comprehensive (Loss) Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(570)
Ending Balance	$ (79)