Loans (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Deferred Income	$ 12,300,000		$ 12,300,000		$ 12,200,000
Troubled Debt Restructuring, Classification removed	1,900,000		2,200,000	$ 0
Partial Charge-Offs On Impaired Loans			11,384,000		10,040,000
Impaired Financing Receivable, Related Allowance	1,396,000		1,396,000		684,000
Recorded investment, related to loans	5,300,000		5,300,000		3,500,000
Troubled Debt Restructuring Included In Nonaccrual Loans	23,900,000		23,900,000		38,500,000
TDRs included in accruing loan totals	16,400,000		16,400,000		20,200,000
Nonaccrual Trouble Debt Restructuring Current	18,100,000		18,100,000		32,400,000
Commitments to lend additional funds to borrowers whose terms had been modified in a TDR	600,000		600,000		1,300,000
Specific reserves related to troubled debt restructuring	500,000		500,000
Additional Specific Reserves Related To Troubled Debt Restructuring	0	$ 10,000	10,000	290,000
Financing Receivable, Modifications, Recorded Investment, During Period	2,374,000	3,036,000	3,767,000	7,569,000
Loan Modifications on Nonacrrual status	5,000	175,000	$ 400,000	2,800,000
Loan past due period before entering default status			30 days
Financing Receivable, Modifications, Subsequent Default, Recorded Investment, During Period	1,235,000	2,110,000	$ 1,380,000	2,326,000
Deposit Liabilities Reclassified as Loans Receivable	1,000,000		1,000,000		1,900,000
Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Partial Charge-Offs On Impaired Loans			9,200,000		7,900,000
Financing Receivable With A Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Partial Charge-Offs On Impaired Loans			2,200,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	589,000	802,000	720,000	1,183,000
Commercial Real Estate [Member] | Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Related Allowance	0		0		0
Commercial Real Estate [Member] | Financing Receivable With A Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Related Allowance	27,000		27,000		$ 2,000
Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	1,223,000	1,477,000	1,511,000	1,725,000
Loans modified during period	21,000	13,000	21,000	13,000
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	455,000	802,000	455,000	803,000
Nonaccrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	1,151,000	1,559,000	2,256,000	5,844,000
Loans modified during period	1,200,000	2,100,000	1,400,000	2,300,000
Nonaccrual [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	134,000		265,000	380,000
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	4,700,000	3,400,000	11,000,000	5,000,000
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	$ 100,000	$ 0	$ 200,000	$ 100,000