Long-Term Debt, Financing and Capital Lease Obligations (Schedule of Maturities of Long-term Debt) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Mar. 31, 2018
Long-term Debt, Fiscal Year Maturity [Abstract]
Fiscal year 2018	$ 4,455
Fiscal year 2019	5,160
Fiscal year 2020	4,926
Fiscal year 2021	2,988
Fiscal year 2022	10,829
Fiscal year 2023 and thereafter	11,970
Long-term debt	40,328
Net premiums	(405)	$ (111)
Current and long-term debt, financing and capital lease obligations	$ 39,923	$ 40,892

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Amount, after accumulated amortization, of debt discount (premium).

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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