Loans and Allowance for Credit Losses (Rollforward of TDRs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	$ 11,781	$ 16,624
Disbursements (Payments)	(676)	(81)
Charge offs		(379)
Payoffs	(197)	(3,006)
TDR ending balance	10,908	13,158
TDR, Related Allowance	492	757
Impaired Nonaccrual Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	3,118	3,298
Disbursements (Payments)	(38)	(20)
Reclassifications/Transfer In/(Out)		154
TDR ending balance	3,080	3,432
TDR, Related Allowance	291	457
Impaired Nonaccrual Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassifications/Transfer In/(Out)		154
TDR ending balance		154
Impaired Nonaccrual Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance		83
TDR ending balance		83
Impaired Nonaccrual Loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	320	337
Disbursements (Payments)	(4)	(4)
TDR ending balance	315	333
TDR, Related Allowance	12	29
Impaired Nonaccrual Loans [Member] | Construction Loans [Member] | Commercial and Residential Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	2,798	2,878
Disbursements (Payments)	(33)	(16)
TDR ending balance	2,765	2,862
TDR, Related Allowance	279	428
Impaired Accruing Restructured Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	8,663	13,326
Disbursements (Payments)	(638)	(61)
Charge offs		(379)
Reclassifications/Transfer In/(Out)		(154)
Payoffs	(197)	(3,006)
TDR ending balance	7,828	9,726
TDR, Related Allowance	201	300
Impaired Accruing Restructured Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	4,454	4,536
Disbursements (Payments)	(23)	(25)
Reclassifications/Transfer In/(Out)		(154)
Payoffs	(197)	(187)
TDR ending balance	4,234	4,170
TDR, Related Allowance	174	223
Impaired Accruing Restructured Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	4,158	4,818
Disbursements (Payments)	(613)	(33)
Payoffs		(219)
TDR ending balance	3,545	4,566
TDR, Related Allowance	27	36
Impaired Accruing Restructured Loans [Member] | Construction Loans [Member] | Commercial and Residential Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	51	3,972
Disbursements (Payments)	(2)	(3)
Charge offs		(379)
Payoffs		(2,600)
TDR ending balance	$ 49	990
TDR, Related Allowance		$ 41