FHLB Borrowings and Other Borrowings (Details)	12 Months Ended
Sep. 30, 2025 USD ($) loan	Sep. 30, 2024 USD ($) loan
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
FHLB borrowings, ratio of maximum borrowing capacity to total assets	45.00%
Number of short-term borrowings \| loan	3	3
Minimum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest rate, stated percentage	3.95%	3.95%
Maximum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest rate, stated percentage	4.03%	4.03%
Pacific Coast Banker's Bank
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Short-term overnight borrowings, maximum borrowing capacity	$ 50,000,000
Overnight line of credit, amount outstanding	0	$ 0
Federal Home Loan Bank Advances
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Long-term FHLB advances	20,000,000	0
Short-term FHLB borrowings, maximum borrowing capacity	70,571,000
Federal Home Loan Bank Advances
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Long-term FHLB advances	0	$ 20,000,000
Short-term FHLB borrowings, maximum borrowing capacity	$ 639,915,000

Federal Home Loan Bank, Advances, Ratio Of Maximum Borrowing Capacity To Total Assets

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Number Of Short Term Debt Instruments

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

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Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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