| **DERIVATIVES (Income Statement Effect) (Details) - USD ($) $ in Thousands** | 3 Months Ended | 9 Months Ended |
|------------------------------------------------------------------------------|----------------|----------------|
||
| Cross-currency swaps | Miscellaneous income | Fair value hedges              |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | $ 0            |           | $ 174 | $ 110 |
| Interest rate swaps | Miscellaneous income | Fair value hedges               |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | 190            | $ (3,985)      | 1,959 | (5,437) |
| Interest rate swaps | Net interest income | Cash flow hedges                 |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | (254)          | (1,775)        | (4,379) | (9,957) |
| Forward commitments to sell loans | Mortgage banking income                  |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | 4,128          | (10,663)       | (4,348) | (1,729) |
| Interest rate lock commitments | Mortgage banking income                     |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | (793)          | 3,595          | 6,645 | 2,417 |
| Mortgage servicing | Mortgage banking income                                 |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | (2,803)        | 11,736         | 21,024 | 1,302 |
| Customer related derivatives | Miscellaneous income                          |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | 24,108         | (1,376)        | 18,985 | (1,049) |
| Foreign exchange | Miscellaneous income                                      |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | 967            | 2,142          | 4,694 | 4,618 |
| Interest rate swaps, caps, and options | Miscellaneous income                |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | 4,329          | (3,825)        | (1,790) | 1,501 |
| Interest rate swaps, caps, and options | Net interest income                 |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | 12,391         | 21,093         | 42,563 | 58,453 |
| Total return settlement | Other administrative expenses                      |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | 343            | 3,836          | (2,337) | (10,197) |
| Other | Miscellaneous income                                                 |           |           |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                         |           |           |   |   |
| Gain (loss) recognized on all derivatives                                    | $ (765)        | $ (1,649)      | $ 974 | $ (2,107) |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
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