Fair Value Of Financial Instruments (Schedule Of Carrying Amounts And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Assets:
AFS securities	$ 2,014,608
AFS securities		$ 1,560,950
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Loans receivable	7,400	5,700
Carrying Amount [Member]
Assets:
Cash and cash equivalents	42,262	185,148
AFS securities	2,014,608
AFS securities		1,560,950
Loans receivable	7,081,142	7,202,851
FHLB stock	73,421	93,862
Liabilities:
Deposits	6,597,396	6,191,408
Borrowings	1,582,850	1,789,313
Interest rate swaps	27,719	53,149
Estimated Fair Value [Member]
Assets:
Cash and cash equivalents	42,262	185,148
AFS securities	2,014,608
AFS securities		1,560,950
Loans receivable	7,534,278	7,663,000
FHLB stock	73,421	93,862
Liabilities:
Deposits	6,649,954	6,259,080
Borrowings	1,611,414	1,840,605
Interest rate swaps	27,719	53,149
Estimated Fair Value [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Cash and cash equivalents	42,262	185,148
AFS securities	0
AFS securities		0
Loans receivable	0	0
FHLB stock	73,421	93,862
Liabilities:
Deposits	3,838,656	3,170,164
Borrowings	0	0
Interest rate swaps	0	0
Estimated Fair Value [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets:
Cash and cash equivalents	0	0
AFS securities	2,014,608
AFS securities		1,560,950
Loans receivable	0	0
FHLB stock	0	0
Liabilities:
Deposits	2,811,298	3,088,916
Borrowings	1,611,414	1,840,605
Interest rate swaps	27,719	53,149
Estimated Fair Value [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Assets:
Cash and cash equivalents	0	0
AFS securities	0
AFS securities		0
Loans receivable	7,534,278	7,663,000
FHLB stock	0	0
Liabilities:
Deposits	0	0
Borrowings	0	0
Interest rate swaps	$ 0	$ 0

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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