Hedging Activities - Derivative Instruments Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2018	Mar. 31, 2018
Derivatives designated for hedge accounting
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	$ 250	$ 29
Fair value of derivative, liability	65	229
Derivatives designated for hedge accounting \| Foreign Exchange Contract \| Prepaid expenses and other
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	19	15
Fair value of derivative, liability	0	0
U.S. Dollar notional amount, asset	81	81
Derivatives designated for hedge accounting \| Foreign Exchange Contract \| Other noncurrent assets
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	18	14
Fair value of derivative, liability	0	0
U.S. Dollar notional amount, asset	81	81
Derivatives designated for hedge accounting \| Cross Currency Swap \| Prepaid expenses and other
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	40	0
Derivatives designated for hedge accounting \| Cross Currency Swap \| Other noncurrent assets
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	173	0
Derivatives designated for hedge accounting \| Cross Currency Swap \| Prepaid expenses and other/Other accrued liabilities
Derivatives, Fair Value [Line Items]
U.S. Dollar notional amount, asset	371	504
Derivatives designated for hedge accounting \| Cross Currency Swap \| Other accrued liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative, liability	16	7
Derivatives designated for hedge accounting \| Cross Currency Swap \| Other noncurrent liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative, liability	49	222
Derivatives designated for hedge accounting \| Cross Currency Swap \| Non-current Asset / Liability
Derivatives, Fair Value [Line Items]
U.S. Dollar notional amount, asset	4,912	3,508
Derivatives not designated for hedge accounting
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	0	0
Fair value of derivative, liability	0	0
Derivatives not designated for hedge accounting \| Foreign Exchange Contract \| Prepaid expenses and other
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	0	0
Fair value of derivative, liability	0	0
U.S. Dollar notional amount, asset	6	13
Derivatives not designated for hedge accounting \| Foreign Exchange Contract \| Other accrued liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	0	0
Fair value of derivative, liability	0	0
U.S. Dollar, notional amount, liability	$ 4	$ 16

Nominal or face amount used to calculate payments on the derivative asset.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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Nominal or face amount used to calculate payments on the derivative liability.

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