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Borrowings - Narrative (Details) |  |  |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Jun. 30, 2023 | Aug. 01, 2022 USD ($) | Oct. 29, 2021 USD ($) extension_option | Oct. 31, 2020 USD ($) | Feb. 29, 2020 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Oct. 28, 2021 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Line of credit outstanding, long-term |  |  |  |  |  | $ 0 | $ 30,000,000 |
Overnight repurchase agreements with depositors |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Daily average interest rate |  |  |  |  |  | 2.21% | 0.24% |
Line of credit |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  |  |  |  | $ 145,000,000 | $ 140,000,000 |
Line of credit outstanding, short-term |  |  |  |  |  | 0 | 0 |
Amount held on deposit |  |  |  |  |  | 250,000 |  |
Secured repurchase line of credit |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  |  |  |  | 75,000,000 | 75,000,000 |
FHLB advances |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Subordinated indebtedness, net |  |  |  |  |  | 6,474,000 |  |
Line of credit | Revolving credit loans |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  | $ 100,000,000 |  |  |  |  | $ 50,000,000.0
Incremental revolving loan maximum |  |  | $ 50,000,000.0 |  |  |  |  |
Debt instrument, option to extend, term |  |  | 364 days |  |  |  |  |
Number of options to extend term | extension_option |  |  | 2 |  |  |  |  |
Line of credit | Revolving credit loans | Secured Overnight Financing Rate (SOFR) |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  |  | 3.35% |  |  |  |  |
Subordinated indebtedness, net |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  |  |  | 4.50% | 4.25% |  |  |
Interest Rate |  |  |  | 4.32% |  |  |  |
Subordinated indebtedness, net |  |  |  |  |  | 194,279,000 | $ 201,765,000 |
Principal amount |  |  |  | $ 80,000,000 | $ 70,000,000 |  |  |
Repurchased amount of notes |  |  |  |  |  | 5,000,000 |  |
Subordinated indebtedness, net | BTH |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Subordinated indebtedness, net |  | $ 37,600,000 |  |  |  | 34,700,000 |  |
Debt instrument, floor rate |  | 3.875% |  |  |  |  |  |
Debt instrument, redemption period, term threshold |  | 5 years |  |  |  |  |  |
Debt instrument, redemption notice period |  | 10 days |  |  |  |  |  |
Subordinated indebtedness, net | Secured Overnight Financing Rate (SOFR) |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate | 3.08% |  |  |  |  |  |  |
Subordinated indebtedness, net | LIBOR |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  |  |  |  | 2.82% |  |  |
Junior Subordinated Debt |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Subordinated indebtedness, net |  |  |  |  |  | 16,356,000 |  |
Remaining purchase discount |  |  |  |  |  | $ 1,016,000 |  |
Junior Subordinated Debt | BTH |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Subordinated indebtedness, net |  | $ 7,200,000 |  |  |  |  |  |
Debt instrument, redemption price, percentage |  | 100.00% |  |  |  |  |  |
Minimum | FHLB advances |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  |  |  |  |  | 1.99% | 1.99% |
Minimum | Line of credit | Revolving credit loans |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Written request prior to maturity, term |  |  | 30 days |  |  |  |  |
Minimum | Subordinated indebtedness, net | BTH |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  | 6.125% |  |  |  |  |  |
Minimum | Subordinated indebtedness, net | Prime Rate | BTH |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  | 0.50% |  |  |  |  |  |
Maximum | FHLB advances |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  |  |  |  |  | 4.57% | 4.57% |
Maximum | Line of credit | Revolving credit loans |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Written request prior to maturity, term |  |  | 60 days |  |  |  |  |
Maximum | Subordinated indebtedness, net | BTH |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  | 6.375% |  |  |  |  |  |
Maximum | Subordinated indebtedness, net | Prime Rate | BTH |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Interest Rate |  | 1.75% |  |  |  |  |  |
FHLB |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Net amounts available under the blanket floating lien |  |  |  |  |  | $ 2,010,000,000.00 | $ 1,290,000,000 |
Federal Reserve Bank of Dallas | Line of credit |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Current borrowing capacity |  |  |  |  |  | 1,420,000,000 | 1,230,000,000 |
Total Loans Receivable |  |  |  |  |  | 1,690,000,000 | 1,760,000,000 |
Line of credit outstanding, long-term |  |  |  |  |  | $ 0 | $ 0 |

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