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SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) |  |  |  | 9 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
May 20, 2025 $ / shares shares | Mar. 01, 2025 $ / shares shares | Apr. 01, 2024 USD ($) | Sep. 30, 2025 USD ($) segment shares | Dec. 31, 2024 USD ($) shares | Sep. 30, 2024 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |
Total assets | $ |  |  |  | $ 18,188,628,000 | $ 12,046,722,000 |
Preferred stock phares per depository share (in dollars per share) | $ / shares | $ 0.025 |  |  |  |  |
Number of reportable segments | segment |  |  |  | 3 |  |
Number of operating segments | segment |  |  |  | 3 |  |
Income tax examination, penalties and interest accrued | $ |  |  |  | $ 100,000 |  |
Accruals for payments of interest and penalties | $ |  |  |  | $ 0 |  | $ 0
Preferred shares issued (in shares) | shares |  |  |  | 222,750 | 0 |
Preferred stock redemption price per share (in dollars per share) | $ / shares |  | $ 1,000 |  |  |  |
M&M | 5.25% Notes Maturing December 4, 2030 | Subordinated Debt |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Principal balance | $ |  |  | $ 4,000,000 |  |  |
Fixed to floating interest rate (as a percent) |  |  | 5.25% |  |  |
Series A Preferred Stock |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Preferred shares issued (in shares) | shares |  | 7,750 |  |  |  |
Preferred stock, dividend rate |  | 8.00% |  |  |  |
Preferred stock, liquidation preference (in dollars per share) | $ / shares |  | $ 1,000 |  |  |  |
Preferred stock redemption price per share (in dollars per share) | $ / shares |  | $ 1,000 |  |  |  |
Depository Shares |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Preferred stock, liquidation preference (in dollars per share) | $ / shares | $ 25 |  |  |  |  |
Stock issued depositary shares (in shares) | shares | 8,600,000 |  |  |  |  |
Series B Preferred Stock |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Preferred stock, liquidation preference (in dollars per share) | $ / shares | $ 1,000 |  |  |  |  |
Preferred stock redemption price per share (in dollars per share) | $ / shares | $ 1,000 |  |  |  |  |
Derivative | Collateral Pledged |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Restricted cash and cash equivalents | $ |  |  |  | $ 14,400,000 |  |
Third-Party Service Provider |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Restricted cash and cash equivalents | $ |  |  |  | 13,600,000 |  |
Federal Reserve Bank |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Restricted cash and cash equivalents | $ |  |  |  | $ 68,100,000 |  |

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