Investments (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($) security	Dec. 31, 2016 USD ($)
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses | $	$ 5,850	$ 7,767
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 were four U.S. government agencies in an unrealized loss position for less than 12 months as of June 30, 2017. The securities are of investment grade and the Corporation does not intend to sell them, and it is not more than 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 June 30, 2017. There were no U.S. government agency investments in an unrealized loss position for more than 12 months as of June 30, 2017.
Available-for-sale, securities in unrealized loss positions, qualitative disclosure, number of positions, less than one year	4
Available-for-sale, securities in unrealized loss positions, qualitative disclosure, number of positions, greater than or equal to one year	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses | $	$ 0	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 June 30, 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 - Nineteen residential mortgage-backed agencies have been in an unrealized loss position for less than 12 months as of June 30, 2017. There were three mortgage-backed agency investments in an unrealized loss position for more than 12 months as of June 30, 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 June 30, 2017.
Held-to-maturity, securities in unrealized loss positions less than twelve months, qualitative disclosure, number of positions	19
Held-to-maturity, securities in unrealized loss positions greater than twelve months, qualitative disclosure, number of positions	3
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 five commercial mortgage-backed agencies in an unrealized loss position for less than 12 months as of June 30, 2017. There were two commercial mortgage-backed agencies in an unrealized loss position for more than 12 months as of June 30, 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 June 30, 2017.
Available-for-sale, securities in unrealized loss positions, qualitative disclosure, number of positions, less than one year	5
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, 12 months or longer, unrealized losses | $	$ 331	0
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Nature	Commercial Mortgage-Backed Agencies – Held to Maturity - There were no collateralized mortgage-backed agency investments in an unrealized loss position as of June 30, 2017.
Held-to-maturity, securities in unrealized loss positions, qualitative disclosure, number of positions	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 four collateralized mortgage obligations in an unrealized loss position for less than 12 months as of June 30, 2017. There was one collateralized mortgage obligation in an unrealized loss position for more than 12 months as of June 30, 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 June 30, 2017.
Available-for-sale, securities in unrealized loss positions, qualitative disclosure, number of positions, less than one year	4
Available-for-sale, securities in unrealized loss positions, qualitative disclosure, number of positions, greater than or equal to one year	1
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses | $	$ 54	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 less than 12 months as of June 30, 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 June 30, 2017. There were no collateralized mortgage obligations in a loss position for more than 12 months as of June 30, 2017.
Held-to-maturity, securities in unrealized loss positions less than twelve months, qualitative disclosure, number of positions	1
Held-to-maturity, securities in unrealized loss positions greater than twelve months, qualitative disclosure, number of positions	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 were three obligations of state and political subdivisions that have been in an unrealized loss position for less than 12 months and two securities that have been in an unrealized loss position for 12 months or more at June 30, 2017. 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 June 30, 2017.
Available-for-sale, securities in unrealized loss positions, qualitative disclosure, number of positions, less than one year	3
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, 12 months or longer, unrealized losses | $	$ 50	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 subdivisions that has been in an unrealized loss for less than 12 months. 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 June 30, 2017. No obligations of state and political subdivisions securities have been in an unrealized loss position for more than 12 months as of June 30, 2017.
Held-to-maturity, securities in unrealized loss positions less than twelve months, qualitative disclosure, number of positions	1
Held-to-maturity, securities in unrealized loss positions greater than twelve months, qualitative disclosure, number of positions	0
Collateralized debt obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale, securities in unrealized loss positions, qualitative disclosure, nature	Collateralized Debt Obligations – Available for Sale - The $5.4 million in unrealized losses greater than 12 months at June 30, 2017 relates to 10 pooled trust preferred securities that are included in the CDO portfolio. See Note 9 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 the first six months of 2017. The unrealized losses on the remaining securities in the portfolio are primarily attributable to continued depression in 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, 12 months or longer, unrealized losses | $	$ 5,415	$ 7,676