Derivative Instruments and Hedging Activities - Narrative (Details) - USD ($)	3 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023
Derivative [Line Items]
Hedge percentage for foreign exchange transactional exposures, minimum	70.00%
Hedge percentage for foreign exchange transactional exposures, maximum	90.00%
Interest rate swaps
Derivative [Line Items]
Derivative, notional amount	$ 600,000,000		$ 600,000,000
Debt instrument, face amount	800,000,000		$ 800,000,000
Net Investment Hedging
Derivative [Line Items]
Pre-tax gains (losses) related to net investment hedges recorded in other comprehensive income	145,000,000	$ 269,000,000
Pre-tax gains (losses) related to net investment hedges reclassified from other comprehensive income	$ 0	$ 0

Hedge percentage for foreign exchange transactional exposures, Maximum.

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Hedge percentage for foreign exchange transactional exposures, Minimum.

+ References

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Face (par) amount of debt instrument at time of issuance.

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Nominal or face amount used to calculate payment on derivative.

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Amount, before tax and reclassification, of gain (loss) from derivative designated and qualifying as net investment hedge.

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Amount, before tax, of reclassification from accumulated other comprehensive income (AOCI) for gain (loss) from derivative designated and qualifying as net investment hedge.

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