Derivative Instruments - Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2020	Mar. 31, 2019
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	$ 0	$ 38
Derivative liability, fair value	20	4
Designated as Hedging Instrument | Other current assets | Foreign currency forward contracts
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	0	38
Designated as Hedging Instrument | Accrued expenses and other current liabilities | Foreign currency forward contracts
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	20	4
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	16	5
Derivative liability, fair value	12	9
Not Designated as Hedging Instrument | Other current assets | Foreign currency forward contracts
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	16	5
Not Designated as Hedging Instrument | Accrued expenses and other current liabilities | Foreign currency forward contracts
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	$ 12	$ 9