Securities (Summary of Volume of State and Political Subdivision Securities Held in Portfolio) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 294,251	$ 324,771
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1,907	5,329
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	3,011	1,514
Debt Securities, Available-for-sale	293,147	$ 328,586
TEXAS
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	15,473
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	147
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	47
Debt Securities, Available-for-sale	15,573
MICHIGAN [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	15,685
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	121
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	137
Debt Securities, Available-for-sale	15,669
CALIFORNIA
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	17,858
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	208
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	86
Debt Securities, Available-for-sale	17,980
ILLINOIS
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	12,342
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	94
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	114
Debt Securities, Available-for-sale	12,322
West Virginia [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	13,171
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	89
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	66
Debt Securities, Available-for-sale	$ 13,194

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
-Name Accounting Standards Codification
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