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Loans - Details and Delinquency Status of Nonperforming Loans (detail, and delinquency status, of non-performing loans (Non-Accrual Loans and Loans Past Due 90 Days or More and Still Accruing) (Details) - USD ($) $ in Thousands | Jun. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | $ 4,111,857 | $ 3,806,617
Non-accrual loans | 10,263 | 7,622
90 Days or More Past Due and Accruing | 211 | 384
Total loans held-for-investment, net | 4,111,857 | 3,806,617
Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Non-accrual loans | 4,022 | 1,882
Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Non-accrual loans | 5,330 | 5,117
Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Non-accrual loans | 304 | 314
Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Non-accrual loans | 332 | 281
Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Non-accrual loans | 275 | 28
Non-Performing Loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 10,474 | 8,006
Non-accrual loans | 10,263 | 7,622
90 Days or More Past Due and Accruing | 211 | 384
Non-Performing Loans | Real estate loans: |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 10,175 | 7,906
Non-accrual loans | 9,988 | 7,594
90 Days or More Past Due and Accruing | 187 | 312
Non-Performing Loans | Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 4,022 | 1,882
Non-accrual loans | 4,022 | 1,882
90 Days or More Past Due and Accruing | 0 | 0
Non-Performing Loans | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 5,357 | 5,264
Non-accrual loans | 5,330 | 5,117
90 Days or More Past Due and Accruing | 27 | 147
Non-Performing Loans | Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 464 | 479
Non-accrual loans | 304 | 314
90 Days or More Past Due and Accruing | 160 | 165
Non-Performing Loans | Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 332 | 281
Non-accrual loans | 332 | 281
90 Days or More Past Due and Accruing | 0 | 0
Non-Performing Loans | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 292 | 100
Non-accrual loans | 275 | 28
90 Days or More Past Due and Accruing | 17 | 72
Non-Performing Loans | Other loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Non-accrual loans | 0 |
90 Days or More Past Due and Accruing | 7 |
Total loans held-for-investment, net | 7 |
Non-Performing Loans | Substandard | Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 4,022 | 1,882
Non-accrual loans | 4,022 | 1,882
90 Days or More Past Due and Accruing | 0 | 0
Non-Performing Loans | Substandard | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 5,357 | 4,984
Non-accrual loans | 5,330 | 4,837
90 Days or More Past Due and Accruing | 27 | 147
Non-Performing Loans | Substandard | Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 464 | 479
Non-accrual loans | 304 | 314
90 Days or More Past Due and Accruing | 160 | 165
Non-Performing Loans | Substandard | Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 332 | 281
Non-accrual loans | 332 | 281
90 Days or More Past Due and Accruing | 0 | 0
Non-Performing Loans | Substandard | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 292 | 28
Non-accrual loans | 275 | 28
90 Days or More Past Due and Accruing | 17 | 0
Non-Performing Loans | Pass | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net |  | 72
Non-accrual loans |  | 0
90 Days or More Past Due and Accruing |  | 72
Non-Performing Loans | Pass | Other loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Non-accrual loans | 0 |
90 Days or More Past Due and Accruing | 7 |
Total loans held-for-investment, net | 7 |
Non-Performing Loans | Special mention | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net |  | 280
Non-accrual loans |  | 280
90 Days or More Past Due and Accruing |  | 0
Non-Performing Loans | Current |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 3,771 | 2,972
Non-Performing Loans | Current | Real estate loans: |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 3,743 | 2,944
Non-Performing Loans | Current | Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 276 | 0
Non-Performing Loans | Current | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 3,279 | 2,944
Non-Performing Loans | Current | Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 | 0
Non-Performing Loans | Current | Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 188 | 0
Non-Performing Loans | Current | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 28 | 28
Non-Performing Loans | Current | Other loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 |
Non-Performing Loans | Current | Substandard | Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 276 | 0
Non-Performing Loans | Current | Substandard | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 3,279 | 2,944
Non-Performing Loans | Current | Substandard | Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 | 0
Non-Performing Loans | Current | Substandard | Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 188 | 0
Non-Performing Loans | Current | Substandard | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 28 | 28
Non-Performing Loans | Current | Pass | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net |  | 0
Non-Performing Loans | Current | Pass | Other loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 |
Non-Performing Loans | Current | Special mention | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net |  | 0
Non-Performing Loans | 30-89 Days Past Due |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 76 | 280
Non-Performing Loans | 30-89 Days Past Due | Real estate loans: |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 76 | 280
Non-Performing Loans | 30-89 Days Past Due | Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 | 280
Non-Performing Loans | 30-89 Days Past Due | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 70 | 0
Non-Performing Loans | 30-89 Days Past Due | Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 | 0
Non-Performing Loans | 30-89 Days Past Due | Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 6 | 0
Non-Performing Loans | 30-89 Days Past Due | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 | 0
Non-Performing Loans | 30-89 Days Past Due | Other loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 |
Non-Performing Loans | 30-89 Days Past Due | Substandard | Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 | 280
Non-Performing Loans | 30-89 Days Past Due | Substandard | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 70 | 0
Non-Performing Loans | 30-89 Days Past Due | Substandard | Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 | 0
Non-Performing Loans | 30-89 Days Past Due | Substandard | Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 6 | 0
Non-Performing Loans | 30-89 Days Past Due | Substandard | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 | 0
Non-Performing Loans | 30-89 Days Past Due | Pass | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net |  | 0
Non-Performing Loans | 30-89 Days Past Due | Pass | Other loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 |
Non-Performing Loans | 30-89 Days Past Due | Special mention | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net |  | 0
Non-Performing Loans | 90 Days or More Past Due |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 6,416 | 4,370
Non-Performing Loans | 90 Days or More Past Due | Real estate loans: |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 6,169 | 4,370
Non-Performing Loans | 90 Days or More Past Due | Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 3,746 | 1,602
Non-Performing Loans | 90 Days or More Past Due | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 1,981 | 2,173
Non-Performing Loans | 90 Days or More Past Due | Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 304 | 314
Non-Performing Loans | 90 Days or More Past Due | Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 138 | 281
Non-Performing Loans | 90 Days or More Past Due | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 247 | 0
Non-Performing Loans | 90 Days or More Past Due | Other loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 0 |
Non-Performing Loans | 90 Days or More Past Due | Substandard | Real estate loans: | Multifamily |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 3,746 | 1,602
Non-Performing Loans | 90 Days or More Past Due | Substandard | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 1,981 | 1,893
Non-Performing Loans | 90 Days or More Past Due | Substandard | Real estate loans: | One-to-four family residential mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 304 | 314
Non-Performing Loans | 90 Days or More Past Due | Substandard | Real estate loans: | Home equity and lines of credit |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 138 | 281
Non-Performing Loans | 90 Days or More Past Due | Substandard | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | 247 | 0
Non-Performing Loans | 90 Days or More Past Due | Pass | Commercial and industrial loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net |  | 0
Non-Performing Loans | 90 Days or More Past Due | Pass | Other loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net | $ 0 |
Non-Performing Loans | 90 Days or More Past Due | Special mention | Real estate loans: | Commercial mortgage |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Total loans held-for-investment, net |  | $ 280

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