Loans (Credit Quality Indicators - Residential, Consumer) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Under 90 Days Past Due [Member] | Accruing Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	$ 1,159,462	$ 1,083,088
Under 90 Days Past Due [Member] | Nonaccrual Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	7,175	5,543
Under 90 Days Past Due [Member] | Homeowner Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	24,376	27,924
Under 90 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	1,191,013	1,116,555
Under 90 Days Past Due [Member] | Home Equity Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	259,880	264,200
Under 90 Days Past Due [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	34,720	36,614
Under 90 Days Past Due [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	32,753	38,375
Under 90 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	327,353	339,189
Over 90 Days Past Due [Member] | Accruing Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	0	0
Over 90 Days Past Due [Member] | Nonaccrual Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	4,524	6,193
Over 90 Days Past Due [Member] | Homeowner Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	0	0
Over 90 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	4,524	6,193
Over 90 Days Past Due [Member] | Home Equity Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	0	0
Over 90 Days Past Due [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	57	658
Over 90 Days Past Due [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	15	110
Over 90 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable	$ 72	$ 768