Fair Value (Fair Value Measurement and Assumptions) (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Assets:
Impaired Loans	$ 22,948,000	$ 22,948,000	$ 53,267,000
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Charges to allowance for probable loan losses in connection with other real estate owned	8,000	170,000	30,000
Adjustment to fair value in connection with other real estate owned	635,000	3,033,000	710,000
Impaired commercial collateral dependent loans	22,948,000	22,948,000	53,267,000
Impaired commercial collateral dependent receivables appraisals to determine fair value within immediately preceding twelve months	16,083,000	16,083,000	18,585,000
Impaired collateral dependent commercial loans with internal evaluation completed within last twelve months	0	0	0
Measured on a non-recurring basis
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Change in net provision, impaired loans	716,000	716,000	2,138,000
Change in net provision, other real estate owned	3,033,000	3,033,000	710,000
Measured on a non-recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Impaired Loans	8,665,000	8,665,000	11,210,000
Non-financial assets:
Other real estate owned	8,886,000	8,886,000	2,000,000
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Impaired commercial collateral dependent loans	8,665,000	8,665,000	11,210,000
Measured on a non-recurring basis | Assets/liabilities measured at fair value
Assets:
Impaired Loans	8,665,000	8,665,000	11,210,000
Non-financial assets:
Other real estate owned	8,886,000	8,886,000	2,000,000
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Impaired commercial collateral dependent loans	$ 8,665,000	$ 8,665,000	$ 11,210,000