Loans and Allowance for Loan Losses (Credit Risk Exposure Indicators by Portfolio Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 3,095,023	$ 3,026,222	$ 2,782,439
Pass (Grades 1 – 6)
Financing Receivable, Recorded Investment [Line Items]
Loans	2,696,045	2,636,966
Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	336,401	346,512
Special Mention (Grade 7)
Financing Receivable, Recorded Investment [Line Items]
Loans	34,859	12,619
Substandard (Grade 8)
Financing Receivable, Recorded Investment [Line Items]
Loans	25,568	28,250
Non-performing
Financing Receivable, Recorded Investment [Line Items]
Loans	2,150	1,875
Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans	1,070,374	992,866	858,369
Residential real estate | Pass (Grades 1 – 6)
Financing Receivable, Recorded Investment [Line Items]
Loans	1,062,825	983,086
Residential real estate | Special Mention (Grade 7)
Financing Receivable, Recorded Investment [Line Items]
Loans	473	887
Residential real estate | Substandard (Grade 8)
Financing Receivable, Recorded Investment [Line Items]
Loans	7,076	8,893
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans	1,243,397	1,269,533	1,164,023
Commercial real estate | Pass (Grades 1 – 6)
Financing Receivable, Recorded Investment [Line Items]
Loans	1,196,683	1,247,190
Commercial real estate | Special Mention (Grade 7)
Financing Receivable, Recorded Investment [Line Items]
Loans	31,753	7,921
Commercial real estate | Substandard (Grade 8)
Financing Receivable, Recorded Investment [Line Items]
Loans	14,961	14,422
Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans	421,108	381,780	373,400
Commercial | Pass (Grades 1 – 6)
Financing Receivable, Recorded Investment [Line Items]
Loans	415,870	374,429
Commercial | Special Mention (Grade 7)
Financing Receivable, Recorded Investment [Line Items]
Loans	2,544	3,688
Commercial | Substandard (Grade 8)
Financing Receivable, Recorded Investment [Line Items]
Loans	2,694	3,663
Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans	312,779	327,763	323,378
Home equity | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	310,653	325,917
Home equity | Non-performing
Financing Receivable, Recorded Investment [Line Items]
Loans	2,126	1,846
Consumer
Financing Receivable, Recorded Investment [Line Items]
Loans	25,772	20,624	18,149
Consumer | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	25,748	20,595
Consumer | Non-performing
Financing Receivable, Recorded Investment [Line Items]
Loans	24	29
HPFC Portfolio Segment
Financing Receivable, Recorded Investment [Line Items]
Loans	21,593	33,656	$ 45,120
HPFC Portfolio Segment | Pass (Grades 1 – 6)
Financing Receivable, Recorded Investment [Line Items]
Loans	20,667	32,261
HPFC Portfolio Segment | Special Mention (Grade 7)
Financing Receivable, Recorded Investment [Line Items]
Loans	89	123
HPFC Portfolio Segment | Substandard (Grade 8)
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 837	$ 1,272