Loan Quality and Allowance for Loan Losses (Troubled Debt Restructuring Loans) (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018 USD ($) item contract	Jun. 30, 2017 item	Jun. 30, 2018 USD ($) item contract	Jun. 30, 2017 item	Dec. 31, 2017 USD ($) contract
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Number of Contracts | contract		17		17		17
Troubled Debt Restructurings: Recorded Investment		$ 11,942		$ 11,942		$ 12,186
Troubled Debt Restructurings That Have Defaulted on Modified Terms in the Last Twelve Months: Number of Contracts | contract
Troubled Debt Restructurings That Have Defaulted on Modified Terms in the Last Twelve Months: Recorded Investment
New During Period, Number of Contracts | item		0	0	0	0
Performing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Recorded Investment	[1]	$ 9,700		$ 9,700		11,555
Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Recorded Investment	[1]	$ 2,242		$ 2,242		$ 631
Residential Real Estate - Construction [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Number of Contracts | contract		1		1		1
Troubled Debt Restructurings: Recorded Investment		$ 462		$ 462		$ 466
Troubled Debt Restructurings That Have Defaulted on Modified Terms in the Last Twelve Months: Number of Contracts | contract
Troubled Debt Restructurings That Have Defaulted on Modified Terms in the Last Twelve Months: Recorded Investment
Residential Real Estate - Construction [Member] | Performing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Recorded Investment	[1]					$ 466
Residential Real Estate - Construction [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Recorded Investment	[1]	$ 462		$ 462
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Number of Contracts | contract		5		5		5
Troubled Debt Restructurings: Recorded Investment		$ 726		$ 726		$ 737
Troubled Debt Restructurings That Have Defaulted on Modified Terms in the Last Twelve Months: Number of Contracts | contract
Troubled Debt Restructurings That Have Defaulted on Modified Terms in the Last Twelve Months: Recorded Investment
Residential Real Estate [Member] | Performing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Recorded Investment	[1]	690		690		701
Residential Real Estate [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Recorded Investment	[1]	$ 36		$ 36		$ 36
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Number of Contracts | contract		11		11		11
Troubled Debt Restructurings: Recorded Investment		$ 10,754		$ 10,754		$ 10,983
Troubled Debt Restructurings That Have Defaulted on Modified Terms in the Last Twelve Months: Number of Contracts | contract
Troubled Debt Restructurings That Have Defaulted on Modified Terms in the Last Twelve Months: Recorded Investment
Commercial Real Estate [Member] | Performing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Recorded Investment	[1]	9,010		9,010		10,388
Commercial Real Estate [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructurings: Recorded Investment	[1]	$ 1,744		$ 1,744		$ 595

[1] The performing status is determined by the loan's compliance with the modified terms.