| **FAIR VALUE - Reconciliation of Assets and Liabilities Using Level 3 Inputs (Details) - Level 3 - Recurring - USD ($) $ in Thousands** | 3 Months Ended | 6 Months Ended |
|-----------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|
||
| **Fair Value, Assets, Unobservable Input Reconciliation [Roll Forward]**                                                                |           |           |   |   |
| Balances, beginning of period                                                                                                           | $ 127,615      | $ 185,727      | $ 113,162 | $ 187,777 |
| Losses in OCI                                                                                                                           | 0              | (175)          | 0 | (331) |
| Gains/(losses) in earnings                                                                                                              | 8,811          | (5,723)        | 29,662 | 2,676 |
| Additions/Issuances                                                                                                                     | 2,312          | 4,015          | 4,832 | 7,626 |
| Settlements                                                                                                                             | (8,118)        | (11,144)       | (17,036) | (25,048) |
| Balances, end of period                                                                                                                 | 130,620        | 172,700        | 130,620 | 172,700 |
| Changes in unrealized gains (losses) included in earnings related to balances still held at end of period                               | 8,707          | (5,409)        | 32,514 | 10,363 |
| RICs HFI                                                                                                                                |           |           |   |   |
| **Fair Value, Assets, Unobservable Input Reconciliation [Roll Forward]**                                                                |           |           |   |   |
| Balances, beginning of period                                                                                                           | 29,485         | 44,568         | 33,529 | 50,391 |
| Losses in OCI                                                                                                                           | 0              | 0              | 0 | 0 |
| Gains/(losses) in earnings                                                                                                              | 0              | 0              | 0 | 0 |
| Additions/Issuances                                                                                                                     | 47             | 0              | 47 | 0 |
| Settlements                                                                                                                             | (3,360)        | (5,132)        | (7,404) | (10,955) |
| Balances, end of period                                                                                                                 | 26,172         | 39,436         | 26,172 | 39,436 |
| Changes in unrealized gains (losses) included in earnings related to balances still held at end of period                               | 0              | 0              | 0 | 0 |
| MSRs                                                                                                                                    |           |           |   |   |
| **Fair Value, Assets, Unobservable Input Reconciliation [Roll Forward]**                                                                |           |           |   |   |
| Balances, beginning of period                                                                                                           | 99,517         | 86,653         | 79,107 | 77,545 |
| Losses in OCI                                                                                                                           | 0              | 0              | 0 | 0 |
| Gains/(losses) in earnings                                                                                                              | 8,789          | (4,925)        | 31,553 | 8,653 |
| Additions/Issuances                                                                                                                     | 863            | 4,015          | 3,383 | 7,626 |
| Settlements                                                                                                                             | (4,758)        | (6,013)        | (9,632) | (14,094) |
| Balances, end of period                                                                                                                 | 104,411        | 79,730         | 104,411 | 79,730 |
| Changes in unrealized gains (losses) included in earnings related to balances still held at end of period                               | 8,789          | (4,925)        | 31,553 | 8,653 |
| Derivatives, net                                                                                                                        |           |           |   |   |
| **Fair Value, Assets, Unobservable Input Reconciliation [Roll Forward]**                                                                |           |           |   |   |
| Balances, beginning of period                                                                                                           | (1,387)        | 4,269          | 526 | 9,448 |
| Losses in OCI                                                                                                                           | 0              | 0              | 0 | 0 |
| Gains/(losses) in earnings                                                                                                              | 22             | (798)          | (1,891) | (5,977) |
| Additions/Issuances                                                                                                                     | 0              | 0              | 0 | 0 |
| Settlements                                                                                                                             | 0              | 0              | 0 | 0 |
| Balances, end of period                                                                                                                 | (1,365)        | 3,471          | (1,365) | 3,471 |
| Changes in unrealized gains (losses) included in earnings related to balances still held at end of period                               | (82)           | (484)          | 961 | 1,710 |
| Other                                                                                                                                   |           |           |   |   |
| **Fair Value, Assets, Unobservable Input Reconciliation [Roll Forward]**                                                                |           |           |   |   |
| Balances, beginning of period                                                                                                           | 0              |           | 0 |   |
| Losses in OCI                                                                                                                           | 0              |           | 0 |   |
| Gains/(losses) in earnings                                                                                                              | 0              |           | 0 |   |
| Additions/Issuances                                                                                                                     | 1,402          |           | 1,402 |   |
| Settlements                                                                                                                             | 0              |           | 0 |   |
| Balances, end of period                                                                                                                 | 1,402          |           | 1,402 |   |
| Changes in unrealized gains (losses) included in earnings related to balances still held at end of period                               | $ 0            |           | $ 0 |   |
| Investments AFS                                                                                                                         |           |           |   |   |
| **Fair Value, Assets, Unobservable Input Reconciliation [Roll Forward]**                                                                |           |           |   |   |
| Balances, beginning of period                                                                                                           |           | 50,237         |   | 50,393 |
| Losses in OCI                                                                                                                           |           | (175)          |   | (331) |
| Gains/(losses) in earnings                                                                                                              |           | 0              |   | 0 |
| Additions/Issuances                                                                                                                     |           | 0              |   | 0 |
| Settlements                                                                                                                             |           | 1              |   | 1 |
| Balances, end of period                                                                                                                 |           | 50,063         |   | 50,063 |
| Changes in unrealized gains (losses) included in earnings related to balances still held at end of period                               |           | $ 0            |   | $ 0 |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.
+ References
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| - Definition
A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.
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No definition available.
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| - Definition
Amount of gain (loss) recognized in income from derivative asset (liability) after deduction of derivative liability (asset), measured at fair value on recurring basis using unobservable input (level 3).
+ References
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| - Definition
Amount of gain (loss) recognized in other comprehensive income from derivative asset (liability) after deduction of derivative liability (asset), measured at fair value on recurring basis using unobservable input (level 3).
+ References
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| - Definition
Amount of issuances of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.
+ References
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| - Definition
Amount of settlements of financial instrument classified as a derivative asset (liability) after deduction of derivative liability, measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.
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