Loans and Allowance for Credit Losses (Rollforward of TDRs) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	$ 18,504	$ 20,923
New TDRs	345	3,598
Disbursements (payments)	(1,119)	(3,000)
Charge offs	(89)	(629)
Reclassifications/transfer in/(out)	(108)
Payoffs	(584)	(179)
TDR ending balance	16,949	20,713
TDR, related allowance	923	1,176
Impaired Nonaccrual Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	5,504	5,428
New TDRs	345	2,570
Disbursements (payments)	(916)	(2,163)
Charge offs		(512)
Reclassifications/transfer in/(out)	(108)	2,053
TDR ending balance	4,825	7,376
TDR, related allowance	690	923
Impaired Nonaccrual Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	1,603	445
Disbursements (payments)	(44)	(293)
Reclassifications/transfer in/(out)		1,595
TDR ending balance	1,559	1,747
TDR, related allowance	110	72
Impaired Nonaccrual Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	83
Charge offs		(258)
Reclassifications/transfer in/(out)		458
TDR ending balance	83	200
TDR, related allowance		112
Impaired Nonaccrual Loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
New TDRs	345
TDR ending balance	345
Impaired Nonaccrual Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance		23
Disbursements (payments)		(23)
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	3,818	4,960
New TDRs		2,570
Disbursements (payments)	(872)	(1,847)
Charge offs		(254)
Reclassifications/transfer in/(out)	(108)
TDR ending balance	2,838	5,429
TDR, related allowance	580	739
Impaired Accruing Restructured Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	13,000	15,495
New TDRs		1,028
Disbursements (payments)	(203)	(837)
Charge offs	(89)	(117)
Reclassifications/transfer in/(out)		(2,053)
Payoffs	(584)	(179)
TDR ending balance	12,124	13,337
TDR, related allowance	233	253
Impaired Accruing Restructured Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	3,875	5,686
New TDRs		533
Disbursements (payments)	(102)	(350)
Charge offs	(89)
Reclassifications/transfer in/(out)		(1,595)
Payoffs	(450)	(179)
TDR ending balance	3,234	4,095
TDR, related allowance	145	73
Impaired Accruing Restructured Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR beginning balance	4,936	5,740
New TDRs		495
Disbursements (payments)	(83)	(659)
Charge offs		(117)
Reclassifications/transfer in/(out)		(458)
TDR ending balance	4,853	5,001
TDR, related allowance	75	155
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	4,189	4,069
Disbursements (payments)	(18)	172
Payoffs	(134)
TDR ending balance	4,037	4,241
TDR, related allowance	$ 13	$ 25