Commitments And Contingent Liabilities (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2020	Sep. 30, 2019
Unfunded And Commitments To Originate [Line Items]
Commitment to securitize and sell mortgage loans	$ 51,446	$ 3,706
Unfunded Commitments, Equity Lines of Credit Including Suspended Accounts
Unfunded And Commitments To Originate [Line Items]
Unfunded commitments on home equity lines of credit (including commitments for suspended accounts)	2,521,450
Subject To Pending Agency Contracts
Unfunded And Commitments To Originate [Line Items]
Commitment to securitize and sell mortgage loans	$ 45,231	$ 0
Minimum
Unfunded And Commitments To Originate [Line Items]
Fixed expiration of commitments to extend credit (in days)	60 days
Home equity line of credit unfunded commitments expiration, years	5 years
Maximum
Unfunded And Commitments To Originate [Line Items]
Fixed expiration of commitments to extend credit (in days)	360 days
Home equity line of credit unfunded commitments expiration, years	10 years