INVESTMENT SECURITIES (Details) - USD ($) |
Sep. 30, 2017 |
Dec. 31, 2016 |
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|---|---|---|---|---|---|
| Available-for-sale | |||||
| Amortized Cost | $ 511,009,000 | $ 523,412,000 | |||
| Unrealized Gains | 1,050,000 | 898,000 | |||
| Unrealized Losses | 1,213,000 | 1,576,000 | |||
| Market Value | 510,846,000 | 522,734,000 | |||
| Held to Maturity | |||||
| Amortized Cost | 184,262,000 | 177,365,000 | |||
| Unrealized Gains | 88,000 | 137,000 | |||
| Unrealized Losses | 827,000 | 756,000 | |||
| Market Value | 183,523,000 | 176,746,000 | |||
| Total | |||||
| Amortized Cost | 695,271,000 | 700,777,000 | |||
| Unrealized Gain | 1,138,000 | 1,035,000 | |||
| Unrealized Loss | 2,040,000 | 2,332,000 | |||
| Fair Value | 694,369,000 | 699,480,000 | |||
| U.S. Government Treasury [Member] | |||||
| Available-for-sale | |||||
| Amortized Cost | 257,635,000 | 286,867,000 | |||
| Unrealized Gains | 32,000 | 262,000 | |||
| Unrealized Losses | 869,000 | 851,000 | |||
| Market Value | 256,798,000 | 286,278,000 | |||
| U.S. Government Agency [Member] | |||||
| Available-for-sale | |||||
| Amortized Cost | 147,550,000 | 131,489,000 | |||
| Unrealized Gains | 729,000 | 495,000 | |||
| Unrealized Losses | 290,000 | 344,000 | |||
| Market Value | 147,989,000 | 131,640,000 | |||
| States and Political Subdivisions [Member] | |||||
| Available-for-sale | |||||
| Amortized Cost | 95,869,000 | 95,197,000 | |||
| Unrealized Gains | 175,000 | 23,000 | |||
| Unrealized Losses | 54,000 | 381,000 | |||
| Market Value | 95,990,000 | 94,839,000 | |||
| Mortgage-Backed Securities [Member] | |||||
| Available-for-sale | |||||
| Amortized Cost | 1,218,000 | 1,312,000 | |||
| Unrealized Gains | 114,000 | 118,000 | |||
| Unrealized Losses | 0 | 0 | |||
| Market Value | 1,332,000 | 1,430,000 | |||
| Equity Securities [Member] | |||||
| Available-for-sale | |||||
| Amortized Cost | [1] | 8,737,000 | 8,547,000 | ||
| Unrealized Gains | 0 | 0 | |||
| Unrealized Losses | 0 | 0 | |||
| Market Value | [1] | 8,737,000 | 8,547,000 | ||
| Federal Home Loan Bank | 3,200,000 | 3,300,000 | |||
| Federal Reserve Bank stock | 4,800,000 | 4,800,000 | |||
| FNBB, Inc. stock | 800,000 | 500,000 | |||
| U.S. Government Treasury [Member] | |||||
| Held to Maturity | |||||
| Amortized Cost | 93,309,000 | 119,131,000 | |||
| Unrealized Gains | 2,000 | 107,000 | |||
| Unrealized Losses | 183,000 | 81,000 | |||
| Market Value | 93,128,000 | 119,157,000 | |||
| U.S. Government Agency [Member] | |||||
| Held to Maturity | |||||
| Amortized Cost | 0 | 0 | |||
| Unrealized Gains | 0 | 0 | |||
| Unrealized Losses | 0 | 0 | |||
| Market Value | 0 | 0 | |||
| States and Political Subdivisions [Member] | |||||
| Held to Maturity | |||||
| Amortized Cost | 7,051,000 | 8,175,000 | |||
| Unrealized Gains | 31,000 | 1,000 | |||
| Unrealized Losses | 2,000 | 38,000 | |||
| Market Value | 7,080,000 | 8,138,000 | |||
| Mortgage-Backed Securities [Member] | |||||
| Held to Maturity | |||||
| Amortized Cost | 83,902,000 | 50,059,000 | |||
| Unrealized Gains | 55,000 | 29,000 | |||
| Unrealized Losses | 642,000 | 637,000 | |||
| Market Value | $ 83,315,000 | $ 49,451,000 | |||
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