Investment Securities (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) security	Dec. 31, 2016 USD ($)
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses | $	$ 754	$ 2,063
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses | $	6,695	7,767
Available-for-sale securities pledged as collateral | $	$ 125,000	121,800
US government agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	U.S. Government Agencies – Available for Sale – There was one U.S. government agency in an unrealized loss position for less than 12 months as of December 31, 2017. There were four U.S. government agencies in an unrealized loss position for 12 months or more. The securities are of the highest investment grade and the Corporation does not intend to sell them, and it is not more likely than not that the Corporation will be required to sell them before recovery of their amortized cost basis, which may be at maturity. Accordingly, management does not consider these investments to be other-than-temporarily impaired at December 31, 2017.
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year	1
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	4
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses | $	$ 69	747
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses | $	$ 675	0
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	U.S. Government Agencies – Held to Maturity – There were no U.S. government agencies in an unrealized loss position as of December 31, 2017.
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	0
Residential mortgage-backed agencies [Member]
Schedule of Investments [Line Items]
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Residential Mortgage-Backed Agencies – Held to Maturity – There were eleven residential mortgage-backed agencies that have been in an unrealized loss position for less than 12 months as of December 31, 2017. There were eleven residential mortgage-backed agencies in an unrealized loss position for 12 months or more as of December 31, 2017. The securities are of the highest investment grade and the Corporation has the intent and ability to hold the investments to maturity. Accordingly, management does not consider these investments to be other-than-temporarily impaired at December 31, 2017.
Held To Maturity Securities in unrealized loss positions qualitative disclosure number of positions less than one year	11
Held to maturity securities in unrealized loss positions qualitative disclosure number of positions greater than or equal to one year	11
Commercial mortgage-backed agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Commercial Mortgage-Backed Agencies – Available for Sale – There were two commercial mortgage-backed agencies in an unrealized loss position for less than 12 months as of December 31, 2017. There were six commercial mortgage-backed agency securities in an unrealized loss position for 12 months or more. The securities are of the highest investment grade and the Corporation does not intend to sell them, and it is not more likely than not that the Corporation will be required to sell them before recovery of their amortized cost basis, which may be at maturity. Accordingly, management does not consider these investments to be other-than-temporarily impaired at December 31, 2017.
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year	2
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	6
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses | $	$ 169	757
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses | $	$ 711	0
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Commercial Mortgage-Backed Agencies – Held to Maturity – There was one commercial mortgage-backed agency in an unrealized loss position for less than 12 months as of December 31, 2017. The security is of the highest investment grade and the Corporation has the intent and ability to hold the investment to maturity. Accordingly, management does not consider this investment to be other-than-temporarily impaired at December 31, 2017. There were no commercial mortgage-backed agencies in an unrealized loss position for 12 months or more.
Held To Maturity Securities in unrealized loss positions qualitative disclosure number of positions less than one year	1
Held to maturity securities in unrealized loss positions qualitative disclosure number of positions greater than or equal to one year	0
Collateralized mortgage obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Collateralized Mortgage Obligations – Available for Sale – There were six collateralized mortgage obligations in an unrealized loss position for less than 12 months as of December 31, 2017. There were two collateralized mortgage obligations in an unrealized loss position for 12 months or more. The securities are of the highest investment grade and the Corporation does not intend to sell them, and it is not more likely than not that the Corporation will be required to sell them before recovery of the amortized cost basis, which may be at maturity. Accordingly, management does not consider these investments to be other-than-temporarily impaired at December 31, 2017.
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year	6
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses | $	$ 472	399
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses | $	$ 443	0
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Collateralized Mortgage Obligations – Held to Maturity – There was one collateralized mortgage obligation in an unrealized loss position for 12 months or more as of December 31, 2017. The security is of the highest investment grade and the Corporation has the intent and ability to hold the investment to maturity. Accordingly, management does not consider this investment to be other-than-temporarily impaired at December 31, 2017. There were no collateralized mortgage obligations in an unrealized loss position for less than 12 months.
Held To Maturity Securities in unrealized loss positions qualitative disclosure number of positions less than one year	1
Held to maturity securities in unrealized loss positions qualitative disclosure number of positions greater than or equal to one year	0
Obligations of states and political subdivisions [Member]
Schedule of Investments [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Obligations of State and Political Subdivisions – Available for Sale – There was one obligation of state and political subdivisions that has been in an unrealized loss position for less than 12 months at December 31, 2017. There were two securities that have been in an unrealized loss position for 12 months or more. These investments are of investment grade as determined by the major rating agencies and management reviews the ratings of the underlying issuers and performs an in-depth credit analysis on the securities. Management believes that this portfolio is well-diversified throughout the United States, and all bonds continue to perform according to their contractual terms. The Corporation does not intend to sell these investments and it is not more likely than not that the Corporation will be required to sell the investments before recovery of their amortized cost basis, which may be at maturity. Accordingly, management does not consider these investments to be other-than-temporarily impaired at December 31, 2017.
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year	1
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses | $	$ 44	160
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses | $	$ 75	91
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Obligations of State and Political Subdivisions – Held to Maturity – There was one obligation of state and political subdivision in an unrealized loss position for less than 12 months as of December 31, 2017. This bond is a Tax Increment Fund (TIF) bond. Management performs an in-depth credit analysis on this security. The Corporation has the intent and ability to hold the investment to maturity. Accordingly, management does not consider this investment to be other-than-temporarily impaired at December 31, 2017. There were no obligations of state and political subdivisions in an unrealized loss position for greater than12 months.
Held To Maturity Securities in unrealized loss positions qualitative disclosure number of positions less than one year	1
Held to maturity securities in unrealized loss positions qualitative disclosure number of positions greater than or equal to one year	0
Collateralized debt obligations [Member]
Schedule of Investments [Line Items]
Impairment losses | $	$ 3,200	3,200
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Collateralized Debt Obligations – Available for Sale - The $4.8 million in unrealized losses greater than 12 months at December 31, 2017 relates to ten pooled trust preferred securities that are included in the CDO portfolio. See Note 23 for a discussion of the methodology used by management to determine the fair values of these securities. Based upon a review of credit quality and the cash flow tests performed by the independent third party, management determined that there were no securities that had credit-related non-cash OTTI charges during 2017. The unrealized losses on the remaining securities in the portfolio are primarily attributable to continued depression in market interest rates, marketability, liquidity and the current economic environment.
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	10
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses | $	$ 0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses | $	$ 4,791	$ 7,676