Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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Debt and Financing Activities - Long Term Debt (Details)		9 Months Ended
	Nov. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 EUR (€)	Dec. 31, 2017 USD ($)	Mar. 31, 2018 USD ($)
Debt Instrument [Line Items]
Long-term debt outstanding		$ 8,736,000,000			$ 7,880,000,000
Proceeds from issuances of notes		1,099,000,000		$ 0
Term Loan \| Euro Dond Due April 2017
Debt Instrument [Line Items]
Bond repaid \| €			€ 500,000,000
Notes payable \| Notes Due November 30, 2020 and Notes Due May 30, 2029
Debt Instrument [Line Items]
Proceeds from issuances of notes	$ 1,100,000,000
Repurchase price of principal outstanding (percent)	101.00%
Notes payable \| Notes Due November 30, 2020
Debt Instrument [Line Items]
Stated rate of notes issued (percent)	3.65%
Principal amount of notes issued	$ 700,000,000
Notes payable \| Notes Due May 30, 2029
Debt Instrument [Line Items]
Stated rate of notes issued (percent)	4.75%
Principal amount of notes issued	$ 400,000,000
Current Portion of Long-term Debt
Debt Instrument [Line Items]
Long-term debt outstanding		$ 1,120,000,000			$ 1,129,000,000