Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk - Schedule of Notional Values For Derivatives Instrument (Details) - Derivative contracts designated as hedging instruments £ in Millions, zł in Millions, $ in Millions |
Jun. 30, 2026
USD ($)
|
Jun. 30, 2026
PLN (zł)
|
Jun. 30, 2026
GBP (£)
|
Sep. 30, 2025
USD ($)
|
Sep. 30, 2025
PLN (zł)
|
Sep. 30, 2025
GBP (£)
|
|---|---|---|---|---|---|---|
| Interest rate contracts | ||||||
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] | ||||||
| Derivative, notional amount | $ 2,550.0 | $ 0.0 | ||||
| Foreign currency forward contracts | Polish Zloty | ||||||
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] | ||||||
| Derivative, notional amount | 55.3 | zł 210.0 | 45.0 | zł 180.0 | ||
| Foreign currency forward contracts | British Pound Sterling | ||||||
| Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items] | ||||||
| Derivative, notional amount | $ 165.4 | £ 124.0 | $ 120.4 | £ 93.0 |