| **DERIVATIVES (Other Derivatives) (Details) - Not designated as hedging instrument - USD ($) $ in Thousands** | Sep. 30, 2016 | Dec. 31, 2015 |
|---------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | $ 50,425,900  | $ 53,877,846  |
| Asset derivatives Fair value                                                                                  | 496,630       | 382,158       |
| Liability derivatives Fair value                                                                              | 442,896       | 392,319       |
| Other                                                                                                         |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 1,091,431     | 899,394       |
| Asset derivatives Fair value                                                                                  | 18,625        | 11,146        |
| Liability derivatives Fair value                                                                              | 20,764        | 14,553        |
| Foreign exchange contracts                                                                                    |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 3,662,011     | 6,599,760     |
| Asset derivatives Fair value                                                                                  | 46,618        | 53,994        |
| Liability derivatives Fair value                                                                              | 39,925        | 45,418        |
| Interest rate swap agreements                                                                                 |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 1,290,484     | 2,443,991     |
| Asset derivatives Fair value                                                                                  | 4             | 1,176         |
| Liability derivatives Fair value                                                                              | 6,813         | 6,668         |
| Interest rate cap agreements                                                                                  |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 9,852,003     | 10,042,293    |
| Asset derivatives Fair value                                                                                  | 11,762        | 33,080        |
| Liability derivatives Fair value                                                                              | 7             | 0             |
| Options for interest rate cap agreements                                                                      |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 9,824,251     | 10,013,912    |
| Asset derivatives Fair value                                                                                  | 0             | 0             |
| Liability derivatives Fair value                                                                              | 11,794        | 32,977        |
| Total return settlement                                                                                       |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 658,471       | 1,404,726     |
| Asset derivatives Fair value                                                                                  | 0             | 0             |
| Liability derivatives Fair value                                                                              | 29,864        | 53,432        |
| Mortgage banking derivatives                                                                                  |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 1,592,924     | 1,019,914     |
| Asset derivatives Fair value                                                                                  | 28,208        | 3,769         |
| Liability derivatives Fair value                                                                              | 4,621         | 3,502         |
| Mortgage banking derivatives | Forward commitments to sell loans                                              |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 754,368       | 396,984       |
| Asset derivatives Fair value                                                                                  | 47            | 550           |
| Liability derivatives Fair value                                                                              | 3,846         | 0             |
| Mortgage banking derivatives | Interest rate lock commitments                                                 |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 438,556       | 187,930       |
| Asset derivatives Fair value                                                                                  | 9,185         | 2,540         |
| Liability derivatives Fair value                                                                              | 0             | 0             |
| Mortgage banking derivatives | Mortgage servicing                                                             |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 400,000       | 435,000       |
| Asset derivatives Fair value                                                                                  | 18,976        | 679           |
| Liability derivatives Fair value                                                                              | 775           | 3,502         |
| Customer related derivatives                                                                                  |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 22,454,325    | 21,453,856    |
| Asset derivatives Fair value                                                                                  | 391,413       | 278,993       |
| Liability derivatives Fair value                                                                              | 329,108       | 235,769       |
| Customer related derivatives | Swaps receive fixed                                                            |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 10,030,283    | 9,110,944     |
| Asset derivatives Fair value                                                                                  | 352,979       | 209,379       |
| Liability derivatives Fair value                                                                              | 945           | 6,023         |
| Customer related derivatives | Swaps pay fixed                                                                |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 10,312,805    | 9,279,446     |
| Asset derivatives Fair value                                                                                  | 3,683         | 16,196        |
| Liability derivatives Fair value                                                                              | 294,089       | 177,114       |
| Customer related derivatives | Other                                                                          |          |          |
| **Derivative Instruments Not Designated as Hedging Instruments [Abstract]**                                   |          |          |
| Notional                                                                                                      | 2,111,237     | 3,063,466     |
| Asset derivatives Fair value                                                                                  | 34,751        | 53,418        |
| Liability derivatives Fair value                                                                              | $ 34,074      | $ 52,632      |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B
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| - References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value as of the balance sheet date of derivative instrument not designated as hedging instrument and classified as an asset.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624163-113959
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value as of the balance sheet date of derivative instrument not designated as hedging instrument and classified as a liability.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624163-113959
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