| **Accumulated Other Comprehensive Income - Reclassifications (Details) (USD $)In Thousands, unless otherwise specified**                                                                                                                                                                                                                                                                                                   | 3 Months Ended | 9 Months Ended |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|
||
| **Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]**                                                                                                                                                                                                                                                                                                                                |           |                |   |  |   |  |   |  |
| Other income - net realized gains on sales of available for sale securities                                                                                                                                                                                                                                                                                                                                                |      |                | $ 843 |  | $ 487 |  | $ 2,134 |  |
| Interest expense - subordinated debentures and term loans                                                                                                                                                                                                                                                                                                                                                                  | (731)          |                | (1,187) |  | (2,189) |  | (4,460) |  |
| Other expenses - salaries and employee benefits                                                                                                                                                                                                                                                                                                                                                                            | (20,616)       |                | (20,083) |  | (61,943) |  | (59,078) |  |
| Income tax expense (benefit)                                                                                                                                                                                                                                                                                                                                                                                               | (2,667)        |                | (3,926) |  | (11,490) |  | (12,714) |  |
| NET INCOME                                                                                                                                                                                                                                                                                                                                                                                                                 | 10,403         |                | 11,236 |  | 33,083 |  | 34,812 |  |
| Amount Reclassified from Accumulated Other Comprehensive Income for the Period                                                                                                                                                                                                                                                                                                                                             |           |                |   |  |   |  |   |  |
| **Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]**                                                                                                                                                                                                                                                                                                                                |           |                |   |  |   |  |   |  |
| NET INCOME                                                                                                                                                                                                                                                                                                                                                                                                                 | (208)          |                | 339 |  | (851) |  | 447 |  |
| Amount Reclassified from Accumulated Other Comprehensive Income for the Period | Unrealized gains (losses) on available for sale securities                                                                                                                                                                                                                                                                                |           |                |   |  |   |  |   |  |
| **Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]**                                                                                                                                                                                                                                                                                                                                |           |                |   |  |   |  |   |  |
| Other income - net realized gains on sales of available for sale securities                                                                                                                                                                                                                                                                                                                                                |      | [1]            | 843 | [1] | 487 | [1] | 2,134 | [1] |
| Income tax expense (benefit)                                                                                                                                                                                                                                                                                                                                                                                               |      | [1]            | (294) | [1] | (170) | [1] | (747) | [1] |
| NET INCOME                                                                                                                                                                                                                                                                                                                                                                                                                 |      | [1]            | 549 | [1] | 317 | [1] | 1,387 | [1] |
| Amount Reclassified from Accumulated Other Comprehensive Income for the Period | Unrealized gains (losses) on cash flow hedges                                                                                                                                                                                                                                                                                             |           |                |   |  |   |  |   |  |
| **Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]**                                                                                                                                                                                                                                                                                                                                |           |                |   |  |   |  |   |  |
| Interest expense - subordinated debentures and term loans                                                                                                                                                                                                                                                                                                                                                                  | (207)          | [2]            |    | [2] | (587) | [2] |    | [2] |
| Income tax expense (benefit)                                                                                                                                                                                                                                                                                                                                                                                               | 72             | [2]            |    | [2] | 205 | [2] |    | [2] |
| NET INCOME                                                                                                                                                                                                                                                                                                                                                                                                                 | (135)          | [2]            |    | [2] | (382) | [2] |    | [2] |
| Amount Reclassified from Accumulated Other Comprehensive Income for the Period | Unrealized gains (losses) on defined benefit plans                                                                                                                                                                                                                                                                                        |           |                |   |  |   |  |   |  |
| **Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]**                                                                                                                                                                                                                                                                                                                                |           |                |   |  |   |  |   |  |
| Other expenses - salaries and employee benefits                                                                                                                                                                                                                                                                                                                                                                            | (112)          |                | (323) |  | (1,209) |  | (1,446) |  |
| Income tax expense (benefit)                                                                                                                                                                                                                                                                                                                                                                                               | 39             |                | 113 |  | 423 |  | 506 |  |
| NET INCOME                                                                                                                                                                                                                                                                                                                                                                                                                 | $ (73)         |                | $ (210) |  | $ (786) |  | $ (940) |  |
|                                                                                                                                                                                                                                                                                                                                                                                                                            |
| [1]For additional detail related to unrealized gains (losses) on available for sale securities and related amounts reclassified from accumulated other comprehensive income see NOTE 3. INVESTMENT SECURITIES.[2]For additional detail related to unrealized gains (losses) on cash flow hedges and related amounts reclassified from accumulated other comprehensive income see NOTE 6. DERIVATIVE FINANCIAL INSTRUMENTS. |

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| - Definition
This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.
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| - Definition
Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.
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| - Definition
Amount of the cost of borrowed funds accounted for as interest expense for debt.
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| - Definition
The aggregate amount of expenditures for salaries, wages, profit sharing and incentive compensation, and other employee benefits, including equity-based compensation, and pension and other postretirement benefit expense.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.
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