Debt and Financing Activities - Schedule of Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 03, 2020	Dec. 01, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Lease and other obligations	$ 272			$ 174
Total debt	7,244			7,387
Less: Current portion	777			1,052
Total long-term debt	$ 6,467			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	$ 0			700
4.75% Notes due March 1, 2021 | Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	4.75%		4.75%
Long-term debt outstanding	$ 0			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
0.90% Notes due December 3, 2025 | Notes payable
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	0.90%	0.90%
Long-term debt outstanding	$ 500			0
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	$ 733			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	$ 729			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	$ 611			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	$ 639			$ 557