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STOCKHOLDERS' EQUITY - Narrative (Details) $ / shares in Units, $ in Millions |  | 12 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 12, 2020 USD ($) $ / shares shares | Dec. 31, 2024 vote $ / shares | Dec. 31, 2023 $ / shares | Jan. 03, 2022 $ / shares
Class of Stock [Line Items] |  |  |  |
Depositary shares, shares issued (in shares) | shares | 13,800,000 |  |  |
Depository shares, percentage of preferred stock | 0.025 |  |  |
Depository shares, equivalent value per preferred share | $ 1,000 |  |  |
Depositary shares, shares issued, value | $ | $ 345 |  |  |
CIT Group Inc. |  |  |  |
Class of Stock [Line Items] |  |  |  |
Common stock, par value (in dollars per share) |  |  |  | $ 0.01
Class A |  |  |  |
Class of Stock [Line Items] |  |  |  |
Common stock, par value (in dollars per share) |  | $ 1 | $ 1 |
Common stock, voting right per share | vote |  | 1 |  |
Class B |  |  |  |
Class of Stock [Line Items] |  |  |  |
Common stock, par value (in dollars per share) |  | $ 1 | $ 1 |
Common stock, voting right per share | vote |  | 16 |  |
Series A |  |  |  |
Class of Stock [Line Items] |  |  |  |
Dividend | 5.375% | 5.375% |  |
Series B | CIT Group Inc. |  |  |  |
Class of Stock [Line Items] |  |  |  |
Common stock, terms of conversion, conversion ratio |  |  |  | 1
Series C |  |  |  |
Class of Stock [Line Items] |  |  |  |
Dividend |  | 5.625% |  |
Series C | CIT Group Inc. |  |  |  |
Class of Stock [Line Items] |  |  |  |
Common stock, terms of conversion, conversion ratio |  |  |  | 1

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