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REGULATORY CAPITAL AND DIVIDENDS - Narrative (Details) |  | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Apr. 01, 2022 USD ($) $ / shares shares | Dec. 31, 2024 USD ($) $ / shares shares | Dec. 31, 2023 USD ($) $ / shares shares | Dec. 31, 2022 USD ($) $ / shares | Jun. 30, 2024 USD ($) | Mar. 31, 2024 USD ($) | Jan. 27, 2021 USD ($) shares | Nov. 01, 2013 USD ($) investor
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Private debt issuance, number of institutional investors | investor |  |  |  |  |  |  |  | 4
Debt face amount |  |  |  |  |  |  |  | $ 70,000,000
Repayment of borrowings |  | $ 509,708,000 | $ 1,119,200,000 | $ 1,332,889,000 |  |  |  |
Dividends available |  | 283,400,000 |  |  |  |  |  |
Dividend reinvestment and stock purchase plan, stockholder's maximum amount of cash payments per quarter in purchase of common stock |  | $ 5,000 |  |  |  |  |  |
Cash dividends on preferred stock (in dollars per share) | $ / shares |  | $ 187.52 | $ 187.52 | $ 140.64 |  |  |  |
Cash dividends on preferred stock |  | $ 1,875,000 | $ 1,875,000 | $ 1,406,000 |  |  |  |
Stock Repurchase Program |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Stock authorized to be repurchased (in shares) | shares |  |  |  |  |  |  | 3,333,000 |
Stock authorized to be repurchased (in shares) |  |  |  |  |  |  | $ 100,000,000 |
Percent of outstanding shares |  |  |  |  |  |  | 6.00% |
Common stock repurchased (in shares) | shares |  | 1,648,466 |  |  |  |  |  |
Available to repurchase (in shares) | shares |  | 1,000,000 |  |  |  |  |  |
Available to repurchase |  | $ 18,400,000 |  |  |  |  |  |
Excise tax |  | $ 500,000 |  |  |  |  |  |
Series A Preferred Stock |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Preferred Stock, issued (in shares) | shares |  | 10,000 | 10,000 |  |  |  |  |
Liquidation value per share (in dollars per share) | $ / shares |  | $ 2,500 | $ 2,500 |  |  |  |  |
Cash dividends on preferred stock (in dollars per share) | $ / shares |  | 187.52 | 187.52 |  |  |  |  |
Depository share dividends (in dollars per share) | $ / shares |  | $ 1.88 | $ 1.88 |  |  |  |  |
Cash dividends on preferred stock |  | $ 1,900,000 | $ 1,900,000 |  |  |  |  |
Series A Preferred Stock | Level One |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Preferred Stock, issued (in shares) | shares | 10,000 |  |  |  |  |  |  |
Dividend rate, percentage | 7.50% |  |  |  |  |  |  |
Liquidation value per share (in dollars per share) | $ / shares | $ 2,500 |  |  |  |  |  |  |
Outstanding preferred stock |  | $ 25,000,000 | $ 25,000,000 |  |  |  |  |
Senior Notes |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Private debt issuance, number of institutional investors | investor |  |  |  |  |  |  |  | 4
Debt face amount |  |  |  |  |  |  |  | $ 70,000,000
Phase out period |  |  | 5 years |  |  |  |  |
Phase out annual percent |  |  | 20.00% |  |  |  |  |
Phase out annual amount |  |  | $ 13,000,000 |  |  |  |  |
Senior Notes | Fixed-to-Floating Rate Senior Notes due 2028 |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Debt face amount |  |  |  |  |  |  |  | $ 5,000,000
Interest rate on notes (as a percent) |  |  |  |  |  |  |  | 5.00%
Senior Notes | Fixed-to-Floating Rate Subordinated Notes due 2028 |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Debt face amount |  |  |  |  |  |  |  | $ 65,000,000
Interest rate on notes (as a percent) |  |  |  |  |  |  |  | 6.75%
Principal redemption |  |  |  |  | $ 25,000,000 | $ 40,000,000 |  |
Senior Notes | Subordinated Notes due 2029 | Level One |  |  |  |  |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |  |  |  |  |
Phase out period |  | 5 years |  |  |  |  |  |
Assumed debt | $ 30,000,000 |  |  |  |  |  |  |

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