Debt and Financing Activities - Commercial Paper Narrative (Details) - USD ($)	9 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2023
Line of Credit Facility [Line Items]
Weighted average interest rate (percent)	5.53%
Commercial Paper
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	$ 4,000,000,000
Proceeds from issuance of commercial paper	4,800,000,000	$ 1,100,000,000
Repayments of commercial paper	4,600,000,000	$ 483,000,000
Commercial paper	$ 218,000,000		$ 0

Weighted average interest rate of debt outstanding.

No definition available.

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

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- Definition

Carrying value as of the balance sheet date of the current portion of long-term unsecured obligations issued by corporations and other borrowers to investors (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19,20)
-Publisher FASB
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- Definition

The cash inflow from borrowing by issuing commercial paper.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
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- Definition

The cash outflow due to repaying amounts borrowed by issuing commercial paper.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
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