| **Loans - Narrative (Details) $ in Thousands**                       | 3 Months Ended | 9 Months Ended | 12 Months Ended |
|----------------------------------------------------------------------|----------------|----------------|-----------------|
||
| **Accounts, Notes, Loans and Financing Receivable [Line Items]**     |           |           |            |   |   |
| Net deferred loan costs                                              | $ 6,428        | $ 5,560        | $ 6,428         | $ 5,560 | $ 5,748 |
| Qualifying first mortgage loans                                      | 311,152        | 245,000        | 311,152         | 245,000 | 239,805 |
| Loans pledged as collateral                                          | 229,769        | 297,712        | $ 229,769       | $ 297,712 | $ 290,247 |
| Loans classified as TDR (loan) | loan                                |           |           | 71              | 67 | 62 |
| Value of loans classified as TDR                                     | $ 25,661       | $ 19,760       | $ 25,661        | $ 19,760 | $ 17,801 |
| Number of Loans | loan                                               | 10             | 14             | 10              | 14 |   |
| Value of TDR loans more than 30 days past due                        | $ 1,271        | $ 1,849        | $ 1,271         | $ 1,849 |   |
| Number of TDR loans more than 30 days past due (loan) | loan         |           | 0              |            | 0 |   |
| Number of loans placed on TDR status (loan) | loan                   | 1              | 0              | 11              | 0 |   |
| Number of TDR loans involved in bankruptcy (loan) | loan             | 4              |           | 4               |   |   |
| Value of TDR loans involved in bankruptcy                            | $ 676          |           | $ 676           |   |   |
| Number of TDR loans on non-accrual status (loan) | loan              | 12             |           | 12              |   |   |
| Value of TDR loans on non-accrual status                             | $ 7,735        |           | $ 7,735         |   |   |
| Number of TDR loans in the process of foreclosure (loan) | loan      | 4              |           | 4               |   |   |
| Loans classified as TDRs in process of foreclosure                   | $ 504          |           | $ 504           |   |   |
| Number of mortgage loans in the process of foreclosure (loan) | loan | 14             | 14             | 14              | 14 |   |
| Value of mortgage loans in the process of foreclosure                | $ 1,337        | $ 1,861        | $ 1,337         | $ 1,861 |   |
| Unallocated                                                          |           |           |            |   |   |
| **Accounts, Notes, Loans and Financing Receivable [Line Items]**     |           |           |            |   |   |
| Number of days past due                                              |           |           | 30 days         | 30 days |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount of loans classified as troubled debt restructurings that are involved in bankruptcy as of the balance sheet date.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of financing receivables that have been modified by troubled debt restructurings during the current period.
+ References
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| X                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Financing Receivable Modifications Number Of Contracts Greater Than 30 Days Past Due
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of financing receivables greater than 30 days past due that have been modified by troubled debt restructurings and that have been placed in the TDR status in the previous 12 months.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Financing Receivable, Number Of Loans Classified As Troubled Debt Restructurings Involved In Foreclosure
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| X                                                                                                                                                                                                                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of loans classified as troubled debt restructurings that are involved in bankruptcy as of the balance sheet date.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of loans classified as troubled debt restructurings that were on non-accrual status as of the balance sheet date.
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No definition available.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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Financing Receivable, Number of Loans Classified As Troubled Debt Restructurings Classified As NonAccrual
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| X                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Financing receivables that are greater than 30 days past due.
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| X                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Loans classified as troubled debt restructurings that are involved in foreclosure as of the balance sheet date.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                           |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Mortgage Loans in Process of Foreclosure, Number
+ References
No definition available.
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| X                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number Of Days Past Due
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
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No definition available.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of the collateral pledged in support of federal home loan bank advances outstanding.
+ References
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| - Definition
Number of financing receivables that have been modified by troubled debt restructurings.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.
+ References
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