Loans And Allowance For Loan Losses (Schedule Of Forbearance Plans According To Payment Deferrals) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Financing Receivable, Loan Forbearance [Line Items]
Real estate loans	$ 13,421,002	$ 13,234,658
Active Forbearance Plans
Financing Receivable, Loan Forbearance [Line Items]
Real estate loans	230,337
Active Forbearance Plans | Payment Deferrals Ending 7/31/2020
Financing Receivable, Loan Forbearance [Line Items]
Real estate loans	5,217
Active Forbearance Plans | Payment Deferrals Ending 8/31/2020
Financing Receivable, Loan Forbearance [Line Items]
Real estate loans	39,503
Active Forbearance Plans | Payment Deferrals Ending 9/30/2020
Financing Receivable, Loan Forbearance [Line Items]
Real estate loans	87,717
Active Forbearance Plans | Payment Deferrals Ending 10/31/2020
Financing Receivable, Loan Forbearance [Line Items]
Real estate loans	97,759
Active Forbearance Plans | Payment Deferrals Ending 11/30/2020
Financing Receivable, Loan Forbearance [Line Items]
Real estate loans	$ 141