| **DERIVATIVES (Tables)**                                                              | 3 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 periods endedMarch 31, 2016 and 2015:    Three-Month PeriodEnded March 31, Derivative Activity Line Item 2016 2015    (in thousands)Fair value hedges:      Cross-currency swaps Miscellaneous income $174 $(36)Interest rate swaps Miscellaneous income (4,484) (2,993)Cash flow hedges:      Pay fixed-receive variable interestrate swaps Net interest income (2,663) (4,451)Other derivative activities:      Forward commitments to sell loans Mortgage banking income (3,912) (187)Interest rate lock commitments Mortgage banking income 4,452 3,937Mortgage servicing Mortgage banking income 15,070 (1,219)Customer related derivatives Miscellaneous income 1,510 418Foreign exchange Miscellaneous income 223 (874)SC non-hedging derivatives Miscellaneous income (5,499) (2,397) Net interest income 15,139 18,044Other Miscellaneous income (1,131) (1,445)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Offsetting Assets                                                                     | Information about financial assets and liabilities that are eligible for offset on the Condensed Consolidated Balance Sheet as of March 31, 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)March 31, 2016            Fair value hedges $804 $— $804 $— $— $804Cash flow hedges 189 — 189 — — 189Other derivative activities(1) 480,529 6,781 473,748 8,024 2,786 462,938Total derivatives subject to a master netting arrangement or similar arrangement 481,522 6,781 474,741 8,024 2,786 463,931Total derivatives not subject to a master netting arrangement or similar arrangement(2) 6,992 — 6,992 — — 6,992Total Derivative Assets $488,514 $6,781 $481,733 $8,024 $2,786 $470,923             Total Financial Assets  $488,514 $6,781 $481,733 $8,024 $2,786 $470,923             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)March 31, 2016            Fair value hedges $7,247 $— $7,247 $111 $11,732 $(4,596)Cash flow hedges 94,576 — 94,576 — 107,011 (12,435)Other derivative activities(1) 439,268 96,925 342,343 3,054 269,200 70,089Total derivatives subject to a master netting arrangement or similar arrangement 541,091 96,925 444,166 3,165 387,943 53,058Total derivatives not subject to a master netting arrangement or similar arrangement(2) 680 — 680 — — 680Total Derivative Liabilities  $541,771 $96,925 $444,846 $3,165 $387,943 $53,738             Total Financial Liabilities $541,771 $96,925 $444,846 $3,165 $387,943 $53,738             December 31, 2015            Fair value hedges $2,098 $— $2,098 $87 $10,602 $(8,591)Cash flow hedges 23,047 5,589 17,458 — 33,799 (16,341)Other derivative activities(1) 319,296 111,190 208,106 4,265 174,849 28,992Total derivatives subject to a master netting arrangement or similar arrangement 344,441 116,779 227,662 4,352 219,250 4,060Total derivatives not subject to a master netting arrangement or similar arrangement(2) — — — — — —Total Derivative Liabilities  $344,441 $116,779 $227,662 $4,352 $219,250 $4,060             Total Financial Liabilities $344,441 $116,779 $227,662 $4,352 $219,250 $4,060(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 March 31, 2016 and December 31, 2015 included: NotionalAmount Asset Liability Weighted Average ReceiveRate Weighted Average PayRate Weighted Average  Life(Years) (dollars in thousands)March 31, 2016           Fair value hedges:           Interest rate swaps$351,000 $804 $7,247 1.38% 2.22% 3.22Cash flow hedges:           Pay fixed — receive floating interest rate swaps11,926,299 189 94,576 0.46% 1.12% 2.92Total$12,277,299 $993 $101,823 0.49% 1.15% 2.93            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 March 31, 2016 and December 31, 2015 included: Notional Asset derivativesFair value Liability derivativesFair value March 31, 2016 December 31, 2015 March 31, 2016 December 31, 2015 March 31, 2016 December 31, 2015 (in thousands)Mortgage banking derivatives:           Forward commitments to sell loans$506,374 $396,518 $— $542 $3,371 $—Interest rate lock commitments349,468 187,930 6,992 2,540 — —Mortgage servicing435,000 435,000 14,916 679 2,669 3,502Total mortgage banking risk management1,290,842 1,019,448 21,908 3,761 6,040 3,502            Customer related derivatives:           Swaps receive fixed9,067,978 9,060,134 351,336 205,397 114 6,023Swaps pay fixed9,291,483 9,273,627 316 16,183 311,595 177,114Other2,852,757 3,035,085 50,076 53,418 49,148 52,502Total customer related derivatives21,212,218 21,368,846 401,728 274,998 360,857 235,639            Other derivative activities:           Foreign exchange contracts2,619,226 2,513,305 33,604 30,262 33,263 30,144Interest rate swap agreements1,984,000 2,399,000 — 1,176 6,580 2,481Interest rate cap agreements9,159,361 10,013,912 13,716 32,950 — —Options for interest rate cap agreements9,159,361 10,013,912 — — 13,785 32,977Other1,009,210 899,394 16,565 11,146 19,423 14,553Total$46,434,218 $48,227,817 $487,521 $354,293 $439,948 $319,296                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |

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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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