| **Investment Securities - Amortized Cost and Fair Value of Available for Sale Securities and Held to Maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands** | Dec. 31, 2015 | Dec. 31, 2014 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Available for Sale, Amortized Cost**                                                                                                                                                |          |          |
| Due in one year or less                                                                                                                                                               | $ 4,658       |          |
| Due after one through five years                                                                                                                                                      | 13,725        |          |
| Due after five through ten years                                                                                                                                                      | 52,878        |          |
| Due after ten years                                                                                                                                                                   | 220,600       |          |
| Amortized Cost                                                                                                                                                                        | 291,861       |          |
| Total Investment Securities                                                                                                                                                           | 640,499       |          |
| **Available for Sale, Fair Value**                                                                                                                                                    |          |          |
| Due in one year or less                                                                                                                                                               | 4,704         |          |
| Due after one through five years                                                                                                                                                      | 14,295        |          |
| Due after five through ten years                                                                                                                                                      | 55,375        |          |
| Due after ten years                                                                                                                                                                   | 231,672       |          |
| Fair Value                                                                                                                                                                            | 306,046       |          |
| Total Investment Securities                                                                                                                                                           | 658,400       |          |
| **Held to Maturity, Amortized Cost**                                                                                                                                                  |          |          |
| Due in one year or less                                                                                                                                                               | 4,144         |          |
| Due after one through five years                                                                                                                                                      | 28,054        |          |
| Due after five through ten years                                                                                                                                                      | 81,483        |          |
| Due after ten years                                                                                                                                                                   | 106,086       |          |
| Amortized Cost                                                                                                                                                                        | 219,767       |          |
| Total Investment Securities                                                                                                                                                           | 618,599       | $ 631,088     |
| **Held to Maturity, Fair Value**                                                                                                                                                      |          |          |
| Due in one year or less                                                                                                                                                               | 4,148         |          |
| Due after one through five years                                                                                                                                                      | 29,175        |          |
| Due after five through ten years                                                                                                                                                      | 83,646        |          |
| Due after ten years                                                                                                                                                                   | 109,765       |          |
| Fair Value                                                                                                                                                                            | 226,734       |          |
| Total Investment Securities                                                                                                                                                           | 632,380       | 647,723       |
| U.S. Government-sponsored mortgage-backed securities                                                                                                                                  |          |          |
| **Available for Sale, Amortized Cost**                                                                                                                                                |          |          |
| Without single maturity date                                                                                                                                                          | 342,550       |          |
| **Available for Sale, Fair Value**                                                                                                                                                    |          |          |
| Without single maturity date                                                                                                                                                          | 346,266       |          |
| **Held to Maturity, Amortized Cost**                                                                                                                                                  |          |          |
| Total Investment Securities                                                                                                                                                           | 398,832       | 426,645       |
| **Held to Maturity, Fair Value**                                                                                                                                                      |          |          |
| Total Investment Securities                                                                                                                                                           | 405,646       | $ 437,660     |
| Equity securities                                                                                                                                                                     |          |          |
| **Available for Sale, Amortized Cost**                                                                                                                                                |          |          |
| Without single maturity date                                                                                                                                                          | 3,912         |          |
| **Available for Sale, Fair Value**                                                                                                                                                    |          |          |
| Without single maturity date                                                                                                                                                          | 3,912         |          |
| Certificates of deposit                                                                                                                                                               |          |          |
| **Available for Sale, Amortized Cost**                                                                                                                                                |          |          |
| Without single maturity date                                                                                                                                                          | 2,176         |          |
| **Available for Sale, Fair Value**                                                                                                                                                    |          |          |
| Without single maturity date                                                                                                                                                          | $ 2,176       |          |

| X                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Available-For-Sale Securities, Debt Maturity, with Single Maturity Date, Amortized Cost
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| - Definition
Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized and fair value hedge accounting adjustments, maturing in the next rolling twelve months following the latest balance sheet presented.
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| - Definition
Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized and fair value hedge accounting adjustments, maturing after the tenth rolling twelve months following the latest balance sheet presented.
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Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized and fair value hedge accounting adjustments, maturing in the sixth rolling twelve months through the tenth rolling twelve months following the latest balance sheet presented.
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Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized and fair value hedge accounting adjustments, maturing in the second rolling twelve months through the fifth rolling twelve months following the latest balance sheet presented
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This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.
+ References
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| - Definition
Amount after adjustments of available-for-sale debt securities at cost, maturing in the next rolling twelve months following the latest balance sheet. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings less cumulative-effect adjustments and fair value hedge accounting adjustments. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Fair value of available-for-sale debt securities maturing in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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Amount after adjustments of available-for-sale debt securities at cost, maturing after the tenth rolling twelve months following the latest balance sheet. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings less cumulative-effect adjustments, and fair value hedge accounting adjustments. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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Fair value of available-for-sale debt securities maturing after the tenth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Amount after adjustments of available-for-sale debt securities at cost, maturing in the sixth through tenth rolling twelve months following the latest balance sheet. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings less cumulative-effect adjustments, and fair value hedge accounting adjustments. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Fair value of available-for-sale debt securities maturing in the sixth through tenth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Amount after adjustments of available-for-sale debt securities at cost, maturing in the second through fifth rolling twelve months following the latest balance sheet. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings less cumulative-effect adjustments, and fair value hedge accounting adjustments. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Fair value of available-for-sale debt securities maturing in the second through fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Amount of available-for-sale debt securities at cost, net of adjustments, that do not have a single maturity date and which the entity has decided to disclose separately rather than allocating the cost over several maturity groupings. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.
+ References
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| - Definition
Amount of available-for-sale debt securities at fair value that do not have a single maturity date and which the entity has decided to disclose separately rather than allocating the fair value over several maturity groupings.
+ References
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| - Definition
Amount of debt securities categorized neither as held-to-maturity nor trading.
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| - Definition
Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.
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Fair value of held-to-maturity debt securities maturing in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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Fair value of held-to-maturity debt securities maturing after the tenth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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No definition available.
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Fair value of held-to-maturity debt securities maturing in the sixth through tenth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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Fair value of held-to-maturity debt securities maturing in the second through fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Fair value of investments in debt securities classified as held-to-maturity.
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