Debt and Financing Activities - Schedule of Long-Term Debt (Details) - USD ($) $ in Millions	Jun. 30, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Lease and other obligations	$ 192	$ 174
Total debt	7,448	7,387
Less: Current portion	1,053	1,052
Total long-term debt	$ 6,395	6,335
3.65% Notes due November 30, 2020 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	3.65%
Long-term debt outstanding	$ 700	700
4.75% Notes due March 1, 2021 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	4.75%
Long-term debt outstanding	$ 323	323
2.70% Notes due December 15, 2022 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	2.70%
Long-term debt outstanding	$ 400	400
2.85% Notes due March 15, 2023 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	2.85%
Long-term debt outstanding	$ 400	400
3.80% Notes due March 15, 2024 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	3.80%
Long-term debt outstanding	$ 1,100	1,100
7.65% Debentures due March 1, 2027 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	7.65%
Long-term debt outstanding	$ 167	167
3.95% Notes due February 16, 2028 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	3.95%
Long-term debt outstanding	$ 600	600
4.75% Notes due May 30, 2029 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	4.75%
Long-term debt outstanding	$ 400	400
6.00% Notes due March 1, 2041 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	6.00%
Long-term debt outstanding	$ 282	282
4.88% Notes due March 15, 2044 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	4.88%
Long-term debt outstanding	$ 411	411
0.63% Euro Notes due August 17, 2021 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	0.63%
Long-term debt outstanding	$ 674	662
1.50% Euro Notes due November 17, 2025 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	1.50%
Long-term debt outstanding	$ 671	659
1.63% Euro Notes due October 30, 2026 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	1.63%
Long-term debt outstanding	$ 562	552
3.13% Sterling Notes due February 17, 2029 \| Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	3.13%
Long-term debt outstanding	$ 566	$ 557

Amount of short-term and long-term debt and lease obligation.

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- Definition

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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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

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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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Amount of long-term debt and lease obligation, classified as noncurrent.

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Amount of long-term debt and lease obligation, classified as current.

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