Derivative Instruments (Schedule Of Derivative Instruments In Statement Of Financial Position, Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Sep. 30, 2019
Not Designated as Hedging Instrument | Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 18,238	$ 10,358
Fair Value	592	44
Not Designated as Hedging Instrument | Interest Rate Lock Commitments | Other Assets
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	18,238	10,358
Fair Value	592	44
Cash Flow Hedge | Designated as Hedging Instrument | Interest Rate Swap
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,000,000	2,750,000
Fair Value	0	0
Cash Flow Hedge | Designated as Hedging Instrument | Interest Rate Swap | Other Assets
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	50,000	825,000
Fair Value	0	0
Cash Flow Hedge | Designated as Hedging Instrument | Interest Rate Swap | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,950,000	1,925,000
Fair Value	$ 0	$ 0