Fair Value (Quantitative Information About Level 3 Fair Value Measurements) (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		$ 933	$ 1,814
Other real estate owned, fair value		14	817
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		933	1,814
Other real estate owned, fair value		14	817
Level 3 [Member] | Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans			4
Level 3 [Member] | Commercial Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		59	46
Level 3 [Member] | Commercial Term [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		781	1,648
Level 3 [Member] | Consumer: Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		$ 93	$ 116
Level 3 [Member] | Minimum [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Disposal costs	[1],[2]	8.00%	(8.00%)
Level 3 [Member] | Minimum [Member] | Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]		0.00%
Disposal costs	[1],[2]		(8.00%)
Level 3 [Member] | Minimum [Member] | Commercial Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	0.00%
Disposal costs	[1],[2]	(8.00%)	(8.00%)
Level 3 [Member] | Minimum [Member] | Commercial Term [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	0.00%
Disposal costs	[1],[2]	(8.00%)	0.00%
Level 3 [Member] | Minimum [Member] | Consumer: Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	0.00%
Disposal costs	[1],[2]	(8.00%)	(8.00%)
Level 3 [Member] | Maximum [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Disposal costs	[1],[2]	8.00%	(8.00%)
Level 3 [Member] | Maximum [Member] | Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]		0.00%
Disposal costs	[1],[2]		(8.00%)
Level 3 [Member] | Maximum [Member] | Commercial Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	0.00%
Disposal costs	[1],[2]	(8.00%)	(8.00%)
Level 3 [Member] | Maximum [Member] | Commercial Term [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	(50.00%)
Disposal costs	[1],[2]	(11.00%)	(9.00%)
Level 3 [Member] | Maximum [Member] | Consumer: Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	0.00%
Disposal costs	[1],[2]	(8.00%)	(8.00%)
Level 3 [Member] | Weighted Average [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Disposal costs	[1],[2]	(8.00%)	(8.00%)
Level 3 [Member] | Weighted Average [Member] | Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]		0.00%
Disposal costs	[1],[2]		(8.00%)
Level 3 [Member] | Weighted Average [Member] | Commercial Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	0.00%
Disposal costs	[1],[2]	(8.00%)	(8.00%)
Level 3 [Member] | Weighted Average [Member] | Commercial Term [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	(6.00%)
Disposal costs	[1],[2]	(10.00%)	(8.00%)
Level 3 [Member] | Weighted Average [Member] | Consumer: Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Appraisal adjustments	[1],[2]	0.00%	0.00%
Disposal costs	[1],[2]	(8.00%)	(8.00%)

[1] Appraisals are adjusted by management for qualitative factors and disposal costs.

[2] Fair value is generally determined through independent appraisals or sales contracts of the underlying collateral, which generally include various level 3 inputs which are not identifiable.