Shareholders' Equity (Details) - USD ($) $ in Thousands		12 Months Ended
Oct. 08, 2015	Dec. 31, 2018	Dec. 31, 2017
Total risk-based capital:
Actual Regulatory Capital - Amount		$ 434,331	$ 396,451
Capital To Risk Weighted Assets		0.00%	0.00%
Minimum Requirement for capital Adequacy Including Capital Buffer Total Risk-Based Capital Ratio		9.875%
Minimum Regulatory Capital Required - Ratio		8.00%	9.25%
Tier 1 capital:
Actual Regulatory Capital - Amount		$ 394,597	$ 357,261
Actual Regulatory Capital - Ratio		0.00%	0.00%
Minimum Requirement for capital Adequacy Including Capital Buffer Tier I Risk-Based Capital Ratio		7.875%
Minimum Regulatory Capital Required - Ratio		6.00%	7.25%
Common equity tier I capital		$ 351,597	$ 316,677
Tier 1 leverage capital ratio:
Actual Regulatory Capital - Amount		$ 394,597	$ 357,261
Actual Regulatory Capital - Ratio		0.00%	0.00%
Minimum Regulatory Capital Required - Ratio		4.00%	4.00%
Common Equity Tier I Risk Based Capital Ratio		0.00%	0.00%
Minimum Requirement for capital Adequacy Including Capital Buffer Common Equity Tier I Risk-Based Capital Ratio		6.375%
Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets		4.50%	5.75%
Capital Conservation Buffer		2.50%
Value Of Trust Preferred Securities Included In Tier One Capital	$ 43,000	$ 43,000
Subordinated Debt	$ 15,000	$ 59,067	$ 58,911
Debt Instrument, Term		10 years
Subordinated Borrowing, Interest Rate	5.50%
Subsidiaries [Member]
Total risk-based capital:
Actual Regulatory Capital - Amount		$ 398,773	$ 369,540
Capital To Risk Weighted Assets		0.00%	0.00%
Minimum Requirement for capital Adequacy Including Capital Buffer Total Risk-Based Capital Ratio		9.875%
Minimum Regulatory Capital Required - Ratio			9.25%
Minimum Regulatory Provision To Be Well Capitalized - Ratio		10.00%	10.00%
Tier 1 capital:
Actual Regulatory Capital - Amount		$ 374,039	$ 345,350
Actual Regulatory Capital - Ratio		0.00%	0.00%
Minimum Requirement for capital Adequacy Including Capital Buffer Tier I Risk-Based Capital Ratio		7.875%
Minimum Regulatory Capital Required - Ratio			7.25%
Minimum Regulatory Provision To Be Well Capitalized - Ratio		8.00%	8.00%
Common equity tier I capital		$ 374,039	$ 345,350
Tier 1 leverage capital ratio:
Actual Regulatory Capital - Amount		$ 374,039	$ 345,350
Actual Regulatory Capital - Ratio		0.00%	0.00%
Minimum Regulatory Capital Required - Ratio		4.00%	4.00%
Minimum Regulatory Provision To Be Well Capitalized - Ratio		5.00%	5.00%
Common Equity Tier I Risk Based Capital Ratio		0.00%	0.00%
Minimum Requirement for capital Adequacy Including Capital Buffer Common Equity Tier I Risk-Based Capital Ratio		6.375%
Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets			5.75%
Common Equity Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets		6.50%	6.50%
Tier II Capital [Domain]
Tier 1 leverage capital ratio:
Subordinated Debt		$ 15,000
Minimum [Member]
Tier 1 leverage capital ratio:
Capital Conservation Buffer		1.875%

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Common equity tier I capital

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Value of trust preferred securities included in Tier I Capital.

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The amount of total capital as defined in the regulations.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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The amount of excess Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Stated interest rate of the subordinated debt.

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Tier 1 Risk Based Capital as defined in the regulations.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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