| **DERIVATIVES (Tables)**                                                              | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
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| **Derivative [Line Items]**                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| Impact of Derivative Activities in the Condensed Consolidated Statement of Operations | The following Condensed Consolidated Statement of Operations line items were impacted by the Company’s derivative activities for the three-month and six-month periods endedJune 30, 2016 and 2015:    Three-Month PeriodEnded June 30,  Six-Month Period Ended June 30,Derivative Activity(1) Line Item 2016 2015 2016 2015    (in thousands)Fair value hedges:          Cross-currency swaps Miscellaneous income $— $185 $174 $149Interest rate swaps Miscellaneous income 6,253 1,541 1,769 (1,452)Cash flow hedges:          Pay fixed-receive variable interestrate swaps Net interest income (1,462) (3,731) (4,125) (8,182)Other derivative activities:          Forward commitments to sell loans Mortgage banking income (4,625) 9,122 (8,537) 8,935Interest rate lock commitments Mortgage banking income 2,986 (5,115) 7,438 (1,178)Mortgage servicing Mortgage banking income 8,757 (9,215) 23,827 (10,434)Customer related derivatives Miscellaneous income (6,481) 654 (4,971) 1,072Foreign exchange Miscellaneous income (7) (990) 216 (1,864)SC non-hedging derivatives Miscellaneous income (698) 6,854 (6,197) 4,457 Net interest income 15,033 19,316 30,172 37,360 Other administrative expense (1,364) (2,078) (2,680) (14,033)Other Miscellaneous income 2,870 987 1,739 (458)(1)  Gains are disclosed as positive numbers while losses are shown as a negative number regardless of the line item being affected.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| Offsetting Assets                                                                     | Information about financial assets and liabilities that are eligible for offset on the Condensed Consolidated Balance Sheet as of June 30, 2016 and December 31, 2015, respectively, is presented in the following tables:  Offsetting of Financial Assets         Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet  Gross Amounts of Recognized Assets Gross Amounts Offset in the Condensed Consolidated Balance Sheet Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet Financial Instruments Cash Collateral Received Net Amount  (in thousands)June 30, 2016            Fair value hedges $575 $— $575 $— $— $575Cash flow hedges 45 — 45 — — 45Other derivative activities(1) 551,276 6,747 544,529 4,663 6,394 533,472Total derivatives subject to a master netting arrangement or similar arrangement 551,896 6,747 545,149 4,663 6,394 534,092Total derivatives not subject to a master netting arrangement or similar arrangement(2) 9,978 — 9,978 — — 9,978Total Derivative Assets $561,874 $6,747 $555,127 $4,663 $6,394 $544,070             Total Financial Assets  $561,874 $6,747 $555,127 $4,663 $6,394 $544,070             December 31, 2015            Fair value hedges $3,742 $— $3,742 $— $— $3,742Cash flow hedges 7,295 — 7,295 — — 7,295Other derivative activities(1) 351,761 10,161 341,600 8,008 16,424 317,168Total derivatives subject to a master netting arrangement or similar arrangement 362,798 10,161 352,637 8,008 16,424 328,205Total derivatives not subject to a master netting arrangement or similar arrangement(2) 2,532 — 2,532 — — 2,532Total Derivative Assets $365,330 $10,161 $355,169 $8,008 $16,424 $330,737             Total Financial Assets  $365,330 $10,161 $355,169 $8,008 $16,424 $330,737(1)Includes customer-related and other derivatives(2)Includes mortgage banking derivatives |
| Offsetting Liabilities                                                                |   Offsetting of Financial Liabilities        Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet  Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Condensed Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Condensed Consolidated Balance Sheet Financial Instruments Cash Collateral Pledged Net Amount  (in thousands)June 30, 2016            Fair value hedges $575 $— $575 $— $— $575Cash flow hedges 94,499 — 94,499 — 82,473 12,026Other derivative activities(1) 511,129 83,758 427,371 3,037 346,646 77,688Total derivatives subject to a master netting arrangement or similar arrangement 606,203 83,758 522,445 3,037 429,119 90,289Total derivatives not subject to a master netting arrangement or similar arrangement(2) 54,672 — 54,672 — — 54,672Total Derivative Liabilities  $660,875 $83,758 $577,117 $3,037 $429,119 $144,961             Total Financial Liabilities $660,875 $83,758 $577,117 $3,037 $429,119 $144,961             December 31, 2015            Fair value hedges $2,098 $— $2,098 $87 $10,602 $(8,591)Cash flow hedges 23,047 — 23,047 — 39,388 (16,341)Other derivative activities(1) 319,296 77,734 241,562 4,265 208,305 28,992Total derivatives subject to a master netting arrangement or similar arrangement 344,441 77,734 266,707 4,352 258,295 4,060Total derivatives not subject to a master netting arrangement or similar arrangement(2) 53,432 — 53,432 — — 53,432Total Derivative Liabilities  $397,873 $77,734 $320,139 $4,352 $258,295 $57,492             Total Financial Liabilities $397,873 $77,734 $320,139 $4,352 $258,295 $57,492(1)Includes customer-related and other derivatives(2)Includes mortgage banking derivatives                                                                                                                                                                          |
| Designated as hedging instrument                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| **Derivative [Line Items]**                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| Schedule of Derivative Instruments                                                    | Derivatives designated as accounting hedges at June 30, 2016 and December 31, 2015 included: NotionalAmount Asset Liability Weighted Average ReceiveRate Weighted Average PayRate Weighted Average  Life(Years) (dollars in thousands)June 30, 2016           Fair value hedges:           Interest rate swaps$42,000 $575 $575 2.06% 2.06% 2.98Cash flow hedges:           Pay fixed — receive floating interest rate swaps9,430,103 45 94,499 0.51% 1.06% 2.79Total$9,472,103 $620 $95,074 0.52% 1.06% 2.79            December 31, 2015           Fair Value hedges:           Cross-currency swaps$16,390 $3,695 $92 4.76% 4.75% 0.11    Interest rate swaps318,000 47 2,006 1.07% 2.31% 3.50Cash flow hedges:           Pay fixed — receive floating interest rate swaps11,030,431 7,295 23,047 0.32% 1.13% 3.00Total$11,364,821 $11,037 $25,145 0.35% 1.17% 3.01                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| Not designated as hedging instrument                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| **Derivative [Line Items]**                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| Schedule of Other Derivative Activities                                               | Other derivative activities at June 30, 2016 and December 31, 2015 included: Notional Asset derivativesFair value Liability derivativesFair value June 30, 2016 December 31, 2015 June 30, 2016 December 31, 2015 June 30, 2016 December 31, 2015 (in thousands)Mortgage banking derivatives:           Forward commitments to sell loans$661,980 $396,518 $— $542 $7,996 $—Interest rate lock commitments380,757 187,930 9,978 2,540 — —Mortgage servicing435,000 435,000 24,734 679 3,729 3,502Total mortgage banking risk management1,477,737 1,019,448 34,712 3,761 11,725 3,502            Customer related derivatives:           Swaps receive fixed9,735,090 9,060,134 419,483 205,397 1 6,023Swaps pay fixed9,975,469 9,273,627 193 16,183 386,146 177,114Other2,859,230 3,035,085 49,083 53,418 48,235 52,502Total customer related derivatives22,569,789 21,368,846 468,759 274,998 434,382 235,639            Other derivative activities:           Foreign exchange contracts2,605,759 2,513,305 31,846 30,262 31,512 30,144Interest rate swap agreements1,582,000 2,399,000 — 1,176 7,225 2,481Interest rate cap agreements8,851,540 10,013,912 6,547 32,950 — —Options for interest rate cap agreements8,851,540 10,013,912 — — 6,550 32,977Total return settlement1,404,726 1,404,726 — — 53,543 53,432Other1,006,199 899,394 19,390 11,146 20,864 14,553Total$48,349,290 $49,632,543 $561,254 $354,293 $565,801 $372,728                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |

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| - Definition
Tabular disclosure of the location and amount of derivative instruments and nonderivative instruments designated as hedging instruments reported before netting adjustments, and the amount of gain (loss) on derivative instruments and nonderivative instruments designated and qualified as hedging instruments.
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| - Definition
Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.
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