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

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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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No definition available.

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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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Fair value amount of debt instrument that was repurchased.

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Face (par) amount of the original debt instrument that was repurchased.

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Amount, after accumulated amortization, of debt premium.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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

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Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

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The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

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Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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Debt and Financing Activities - Long-Term Debt Narrative (Details) € in Millions			3 Months Ended		6 Months Ended
	Aug. 12, 2021 USD ($)	Jul. 23, 2021 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Jul. 17, 2021 USD ($)	Jul. 17, 2021 EUR (€)	Mar. 31, 2021 USD ($)
Debt Instrument [Line Items]
Long-term debt			$ 5,985,000,000		$ 5,985,000,000				$ 7,148,000,000
Current portion of long-term debt			39,000,000		39,000,000				$ 742,000,000
Payments for debt extinguishments					184,000,000	$ 0
Loss on debt extinguishment			$ 191,000,000	$ 0	$ 191,000,000	0
Term Loan
Debt Instrument [Line Items]
Redemption price percentage of principal (percent)					101.00%
0.63% Euro Notes due August 17, 2021 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)			0.63%		0.63%		0.63%	0.63%
Debt principal redeemed							$ 709,000,000	€ 600
2.85% Notes due March 15, 2023 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		2.85%	2.85%		2.85%
3.80% Notes due March 15, 2024 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		3.80%	3.80%		3.80%
7.65% Debentures due March 1, 2027 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		7.65%	7.65%		7.65%
3.95% Notes due February 16, 2028 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		3.95%	3.95%		3.95%
4.75% Notes due May 30, 2029 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		4.75%	4.75%		4.75%
6.00% Notes due March 1, 2041 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		6.00%	6.00%		6.00%
4.88% Notes due March 15, 2044 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		4.88%	4.88%		4.88%
Tender Offer Notes \| Term Loan
Debt Instrument [Line Items]
Debt principal redeemed		$ 922,000,000
Aggregate consideration of debt redeemed		$ 1,100,000,000
Redemption price percentage of principal (percent)		100.00%
Payments for debt extinguishments		$ 182,000,000
Accrued unpaid interest		14,000,000
1.30% Notes due August 15, 2026 \| Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)	1.30%		1.30%		1.30%
Debt principal amount	$ 500,000,000
Proceeds from debt issuance	$ 495,000,000
The 2020 Credit Facility \| Unsecured Debt \| Revolving Credit Facility
Debt Instrument [Line Items]
Borrowings under facility			$ 0	$ 0	$ 0	$ 0
Notes and Debentures Extinguished February72018 \| Term Loan
Debt Instrument [Line Items]
Loss on debt extinguishment		191,000,000
Debt premiums		182,000,000
Write-off of unamortized debt issuance costs and transaction fees		$ 9,000,000