Loans (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Deferred Income	$ 12,000,000		$ 12,000,000		$ 11,100,000
Troubled Debt Restructuring, Classification removed		$ 335,000	0	$ 2,000,000
Partial Charge-Offs On Impaired Loans			9,946,000		24,943,000
Impaired Financing Receivable, Related Allowance	5,102,000		5,102,000		548,000
Recorded investment, related to loans	18,000,000		18,000,000		2,100,000
Troubled Debt Restructuring Included In Nonaccrual Loans	42,100,000		42,100,000		46,900,000
TDRs included in accruing loan totals	19,500,000		19,500,000		18,200,000
Nonaccrual Trouble Debt Restructuring Current	35,600,000		35,600,000		38,000,000
Commitments to lend additional funds to borrowers whose terms had been modified in a TDR	500,000		500,000		700,000
Specific reserves related to troubled debt restructuring	800,000		800,000		200,000
Additional Specific Reserves Related To Troubled Debt Restructuring	0	0	290,000	975,000
Financing Receivable, Modifications, Recorded Investment, During Period	4,938,000	12,422,000	10,765,000	18,779,000
Loan Modifications on Nonacrrual status	500,000	7,600,000	$ 3,000,000	8,500,000
Loan past due period before entering default status			30 days
Financing Receivable, Modifications, Subsequent Default, Recorded Investment, During Period	825,000	3,869,000	$ 1,088,000	3,951,000
Deposit Liabilities Reclassified as Loans Receivable	1,800,000		1,800,000		2,900,000
Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Partial Charge-Offs On Impaired Loans			7,500,000		24,700,000
Financing Receivable With A Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Partial Charge-Offs On Impaired Loans			2,400,000		200,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	1,455,000	1,777,000	2,320,000	5,118,000
Financing Receivable, Modifications, Subsequent Default, Recorded Investment, During Period	72,000	808,000	248,000	808,000
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	320,000		320,000		$ 309,000
Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	2,061,000	246,000	3,608,000	3,214,000
Loans modified during period	0	14,000	2,000	14,000
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	974,000		1,525,000	2,812,000
Nonaccrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	2,877,000	12,176,000	7,157,000	15,565,000
Loans modified during period		3,900,000	1,100,000	3,900,000
Nonaccrual [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	481,000	1,777,000	795,000	2,306,000
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	3,100,000	1,300,000	6,700,000	5,100,000
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	$ 918,000	$ 425,000	$ 1,000,000	$ 437,000