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Hedging Activities - Summary of Derivative Instruments Gain (Loss) (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023
Derivatives, Fair Value [Line Items] |  |  |  |
Derivatives designated as cash flow and other hedges: | $ 0 | $ 0 | $ 0 | $ 0
Derivatives designated for hedge accounting | Cross-currency swaps | Net Investment Hedging |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivatives designated as net investment hedges: | (20,000,000) | 27,000,000 | (13,000,000) | 7,000,000
Derivatives designated for hedge accounting | Cross-currency swaps | Cash Flow Hedges |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivatives designated as cash flow and other hedges: | (14,000,000) | 33,000,000 | (14,000,000) | 27,000,000
Derivatives designated for hedge accounting | Foreign currency forwards | Cash Flow Hedges |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivatives designated as cash flow and other hedges: | 2,000,000 | 0 | 2,000,000 | 0
Derivatives designated for hedge accounting | Fixed interest rate swaps | Cash Flow Hedges |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivatives designated as cash flow and other hedges: | $ 0 | $ 0 | $ 0 | $ 16,000,000

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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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