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Hedging Activities - Summary of Derivative Instruments Gain (Loss) (Details) - USD ($) | 12 Months Ended
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Mar. 31, 2025 | Mar. 31, 2024 | Mar. 31, 2023
Derivatives, Fair Value [Line Items] |  |  |
Derivatives designated as cash flow and other hedges: | $ 0 | $ 0 | $ 0
Derivatives designated for hedge accounting | Net Investment Hedging | Cross-currency swaps |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivatives designated as net investment hedges: | 80,000,000 | 3,000,000 | 28,000,000
Derivatives designated for hedge accounting | Cash Flow Hedging | Cross-currency swaps |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivatives designated as cash flow and other hedges: | (4,000,000) | 39,000,000 | (54,000,000)
Derivatives designated for hedge accounting | Cash Flow Hedging | Fixed interest rate swaps |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivatives designated as cash flow and other hedges: | 0 | 14,000,000 | (30,000,000)
Derivatives designated for hedge accounting | Cash Flow Hedging | Interest rate swap locks, Foreign currency forwards and Other |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivatives designated as cash flow and other hedges: | $ (6,000,000) | $ 0 | $ 0

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- Definition Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-11 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-15 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (c) -SubTopic 10 -Topic 815 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C + Details
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- Definition Amount, before tax, of reclassification from accumulated other comprehensive income (AOCI) for gain (loss) from derivative designated and qualifying as net investment hedge. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4CCC -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4CCC + Details
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