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Fair Value (Recorded amount of assets and liabilities measured at fair value) (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017
--- | --- | ---
AFS Securities |  |
AFS securities | $ 501,139 | $ 548,730
Available-for-sale Securities, Equity Securities | 0 | 3,577
Fair value, total | 530,870 | 568,554
Level 1 [Member] |  |
AFS Securities |  |
Fair value, total | $ 0 | $ 3,577
Percent of assets and liabilities measured at fair value | 0.00% | 0.63%
Level 2 [Member] |  |
AFS Securities |  |
Fair value, total | $ 501,590 | $ 549,021
Percent of assets and liabilities measured at fair value | 94.48% | 96.56%
Level 3 [Member] |  |
AFS Securities |  |
Fair value, total | $ 29,280 | $ 15,956
Percent of assets and liabilities measured at fair value | 5.52% | 2.81%
Recurring items [Member] |  |
AFS Securities |  |
AFS securities | $ 501,139 | $ 548,730
Available-for-sale Securities, Equity Securities | 0 | 3,577
Derivative instruments | (451) | 291
Recurring items [Member] | Government sponsored enterprises [Member] |  |
AFS Securities |  |
AFS securities | 180 | 216
Recurring items [Member] | States and political subdivisions [Member] |  |
AFS Securities |  |
AFS securities | 193,957 | 208,474
Recurring items [Member] | Auction rate money market preferred [Member] |  |
AFS Securities |  |
AFS securities | 3,108 | 3,049
Recurring items [Member] | Mortgage-backed securities [Member] |  |
AFS Securities |  |
AFS securities | 188,136 | 208,797
Recurring items [Member] | Collateralized mortgage obligations [Member] |  |
AFS Securities |  |
AFS securities | 115,758 | 128,194
Recurring items [Member] | Level 1 [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Available-for-sale Securities, Equity Securities | 0 | 3,577
Derivative instruments | 0 | 0
Recurring items [Member] | Level 1 [Member] | Government sponsored enterprises [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 1 [Member] | States and political subdivisions [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 1 [Member] | Auction rate money market preferred [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 1 [Member] | Mortgage-backed securities [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 1 [Member] | Collateralized mortgage obligations [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 2 [Member] |  |
AFS Securities |  |
AFS securities | 501,139 | 548,730
Available-for-sale Securities, Equity Securities | 0 | 0
Derivative instruments | 451 | 291
Recurring items [Member] | Level 2 [Member] | Government sponsored enterprises [Member] |  |
AFS Securities |  |
AFS securities | 180 | 216
Recurring items [Member] | Level 2 [Member] | States and political subdivisions [Member] |  |
AFS Securities |  |
AFS securities | 193,957 | 208,474
Recurring items [Member] | Level 2 [Member] | Auction rate money market preferred [Member] |  |
AFS Securities |  |
AFS securities | 3,108 | 3,049
Recurring items [Member] | Level 2 [Member] | Mortgage-backed securities [Member] |  |
AFS Securities |  |
AFS securities | 188,136 | 208,797
Recurring items [Member] | Level 2 [Member] | Collateralized mortgage obligations [Member] |  |
AFS Securities |  |
AFS securities | 115,758 | 128,194
Recurring items [Member] | Level 3 [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Available-for-sale Securities, Equity Securities | 0 | 0
Derivative instruments | 0 | 0
Recurring items [Member] | Level 3 [Member] | Government sponsored enterprises [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 3 [Member] | States and political subdivisions [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 3 [Member] | Auction rate money market preferred [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 3 [Member] | Mortgage-backed securities [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Recurring items [Member] | Level 3 [Member] | Collateralized mortgage obligations [Member] |  |
AFS Securities |  |
AFS securities | 0 | 0
Nonrecurring items [Member] |  |
AFS Securities |  |
Impaired loans (net of the allowance for loan losses) | 29,280 | 15,956
Nonrecurring items [Member] | Level 1 [Member] |  |
AFS Securities |  |
Impaired loans (net of the allowance for loan losses) | 0 | 0
Nonrecurring items [Member] | Level 2 [Member] |  |
AFS Securities |  |
Impaired loans (net of the allowance for loan losses) | 0 | 0
Nonrecurring items [Member] | Level 3 [Member] |  |
AFS Securities |  |
Impaired loans (net of the allowance for loan losses) | $ 29,280 | $ 15,956

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