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DERIVATIVES AND HEDGING ACTIVITIES - Impact of Derivative Instruments on AOCI (Details) - Cash flow hedging - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Derivative [Line Items]
Total pre-tax gain/(loss) recognized in AOCI	$ (18,040)	$ (67,102)
Pay fixed/receive floating swaps on cash flow hedges of borrowings
Derivative [Line Items]
Pay fixed/receive floating swaps on cash flow hedges of borrowings	$ (18,040)	$ (67,102)

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Amount, before tax and after reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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