Derivative Instruments (Schedule Of Derivative Instruments In Statement Of Financial Position, Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Not Designated as Hedging Instrument | Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 57,400	$ 10,358
Fair Value	694	44
Not Designated as Hedging Instrument | Interest Rate Lock Commitments | Other Assets
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	14,164	10,358
Fair Value	681	44
Cash Flow Hedge | Designated as Hedging Instrument | Interest Rate Swap
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,075,000	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	0	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	3,075,000	1,925,000
Fair Value	$ 0	$ 0