Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 7,846	$ 13,889	$ 14,160
Ending Balance	5,279	7,846	13,889
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(1,403)	(1,396)	(1,104)
Accumulated other comprehensive income (loss) before reclassifications	(78)	(7)	(298)
Amounts reclassified from accumulated other comprehensive income (loss)			6
Ending Balance	(1,481)	(1,403)	(1,396)
Derivative Financial Instruments, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(4)	(14)	7
Accumulated other comprehensive income (loss) before reclassifications	4	(2)	(19)
Amounts reclassified from accumulated other comprehensive income (loss)	19	12	(2)
Ending Balance	19	(4)	(14)
Defined Benefit Plans, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(16)	(27)	(13)
Accumulated other comprehensive income (loss) before reclassifications	(30)	12	(13)
Amounts reclassified from accumulated other comprehensive income (loss)	(1)	(1)	(1)
Ending Balance	(47)	(16)	(27)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(1,423)	(1,437)	(1,110)
Accumulated other comprehensive income (loss) before reclassifications	(104)	3	(330)
Amounts reclassified from accumulated other comprehensive income (loss)	18	11	3
Ending Balance	$ (1,509)	$ (1,423)	$ (1,437)