Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] |
| | Fair Value Measurements at March 31, 2017 Using | | | | | Quoted Prices in | | | | | | | | | Active Markets | | Significant Other | | Significant | | | | | for Identical | | Observable Inputs | | Unobservable | | | | | Assets (Level 1) | | (Level 2) | | Inputs (Level 3) | | Total | Assets Measured on a Recurring Basis: | | (In Thousands) | Available for sale debt securities: | | | | | | | | | | | | | | | | | U.S. Treasury and government sponsored agencies | | $ | | | | $ | | | | $ | | | | $ | | | Mortgage-backed securities | | | | | | | | | | | | | | | | | State and municipal securities | | | | | | | | | | | | | | | | | Corporate debt | | | | | | | | | | | | | | | | | Total assets at fair value | | $ | | | | $ | | | | $ | | | | $ | | |
| | Fair Value Measurements at December 31, 2016 Using | | | | Quoted Prices in | | | | | | | | | Active Markets | | Significant Other | | Significant | | | | | for Identical | | Observable Inputs | | Unobservable | | | | | Assets (Level 1) | | (Level 2) | | Inputs (Level 3) | | Total | Assets Measured on a Recurring Basis: | | (In Thousands) | Available for sale debt securities: | | | | | | | | | | | | | | | | | U.S. Treasury and government sponsored agencies | | $ | | | | $ | | | | $ | | | | $ | | | Mortgage-backed securities | | | | | | | | | | | | | | | | | State and municipal securities | | | | | | | | | | | | | | | | | Corporate debt | | | | | | | | | | | | | | | | | Total assets at fair value | | $ | | | | $ | | | | $ | | | | $ | | |
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Fair Value Measurements, Nonrecurring [Table Text Block] |
| | Fair Value Measurements at March 31, 2017 Using | | | | | Quoted Prices in | | | | | | | | | Active Markets | | Significant Other | | Significant | | | | | for Identical | | Observable | | Unobservable | | | | | Assets (Level 1) | | Inputs (Level 2) | | Inputs (Level 3) | | Total | Assets Measured on a Nonrecurring Basis: | | (In Thousands) | Impaired loans | | $ | | | | $ | | | | $ | | | | $ | | | Other real estate owned and repossessed assets | | | | | | | | | | | | | | | | | Total assets at fair value | | $ | | | | $ | | | | $ | | | | $ | | |
| | Fair Value Measurements at December 31, 2016 Using | | | | | Quoted Prices in | | | | | | | | | Active Markets | | Significant Other | | Significant | | | | | for Identical | | Observable | | Unobservable | | | | | Assets (Level 1) | | Inputs (Level 2) | | Inputs (Level 3) | | Total | Assets Measured on a Nonrecurring Basis: | | (In Thousands) | Impaired loans | | $ | | | | $ | | | | $ | | | | $ | | | Other real estate owned | | | | | | | | | | | | | | | | | Total assets at fair value | | $ | | | | $ | | | | $ | | | | $ | | |
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Fair Value, by Balance Sheet Grouping [Table Text Block] |
| | March 31, 2017 | | December 31, 2016 | | | Carrying | | | | Carrying | | | | | Amount | | Fair Value | | Amount | | Fair Value | | | (In Thousands) | Financial Assets: | | | | | | | | | | | | | | | | | Level 1 inputs: | | | | | | | | | | | | | | | | | Cash and due from banks | | $ | 338,174 | | | $ | 338,174 | | | $ | 623,562 | | | $ | 623,562 | | | | | | | | | | | | | | | | | | | Level 2 inputs: | | | | | | | | | | | | | | | | | Available for sale debt securities | | $ | 453,956 | | | $ | 453,956 | | | $ | 422,375 | | | $ | 422,375 | | Held to maturity debt securities | | | 34,547 | | | | 34,892 | | | | 25,052 | | | | 25,431 | | Equity securities | | | 1,034 | | | | 1,034 | | | | 1,024 | | | | 1,024 | | Federal funds sold | | | 127,390 | | | | 127,390 | | | | 160,435 | | | | 160,435 | | Mortgage loans held for sale | | | 6,599 | | | | 6,718 | | | | 4,675 | | | | 4,736 | | Bank owned life insurance contracts | | | 115,112 | | | | 115,112 | | | | 114,388 | | | | 114,388 | | | | | | | | | | | | | | | | | | | Level 3 Inputs: | | | | | | | | | | | | | | | | | Held to maturity debt securities | | $ | 37,510 | | | $ | 38,288 | | | $ | 37,512 | | | $ | 37,871 | | Loans, net | | | 5,098,092 | | | | 5,111,532 | | | | 4,859,877 | | | | 4,872,689 | | | | | | | | | | | | | | | | | | | Financial Liabilities: | | | | | | | | | | | | | | | | | Level 2 inputs: | | | | | | | | | | | | | | | | | Deposits | | $ | 5,361,532 | | | $ | 5,358,573 | | | $ | 5,420,311 | | | $ | 5,417,320 | | Federal funds purchased | | | 358,241 | | | | 358,241 | | | | 355,944 | | | | 355,944 | | Other borrowings | | | 55,169 | | | | 54,234 | | | | 55,262 | | | | 54,203 | |
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