Loans (Credit Quality Indicators - Commercial) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	$ 1,798,130	$ 1,746,145
Pass [Member] | Commercial Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	1,067,373	1,065,358
Pass [Member] | Commercial Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	138,008	121,371
Pass [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	592,749	559,416
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	9,804	9,714
Special Mention [Member] | Commercial Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	0	776
Special Mention [Member] | Commercial Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	0	0
Special Mention [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	9,804	8,938
Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	14,895	15,807
Classified [Member] | Commercial Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	5,114	8,052
Classified [Member] | Commercial Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	0	0
Classified [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	$ 9,781	$ 7,755