Derivative Financial Instruments - Schedule of Total Value by Underlying Risk Recognized in Other Comprehensive Income and Reclassified from AOCI to Statement of Operations (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments Gain Loss [Line Items]
Loss recognized in other comprehensive income (loss)	$ (74)	$ (58)
Revenues	1,906	2,063
Cost of operations	1,853	1,928
Interest expense, net	(56)	(92)
Designated as Hedging Instrument [Member] | Foreign Exchange Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Loss recognized in other comprehensive income (loss)	(49)	(7)
Revenues	(1)	1
Cost of operations	(3)	1
Designated as Hedging Instrument [Member] | Interest Rate Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Loss recognized in other comprehensive income (loss)		(15)
Interest expense, net		1
Derivatives not Designated as Hedges [Member] | Foreign Exchange Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Revenues		$ 1
Cost of operations	(2)
Derivatives not Designated as Hedges [Member] | Interest Rate Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Interest expense, net	$ (20)