Loans and Allowance for Credit Losses (Impaired Financing Receivables by Loan Class) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	$ 20,932		$ 20,150
Recorded investment with no allowance	16,156		13,354
Recorded investment with an allowance	3,549		6,063
Related allowance	353		975
Quarter-to-date average recorded investment	18,172	$ 23,680
Interest income recognized	63	85
Impaired Nonaccrual Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	12,767		11,323
Recorded investment with no allowance	10,106		6,656
Recorded investment with an allowance	1,434		3,934
Related allowance	161		776
Quarter-to-date average recorded investment	10,704	15,772
Impaired Accruing Restructured Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	7,444		7,501
Recorded investment with no allowance	5,329		5,372
Recorded investment with an allowance	2,115		2,129
Related allowance	192		199
Quarter-to-date average recorded investment	7,468	7,908
Interest income recognized	63	85
Other Impaired Accruing Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	721		1,326
Recorded investment with no allowance	721		1,326
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	8,056		7,257
Recorded investment with no allowance	4,835		3,817
Recorded investment with an allowance	2,817		3,255
Related allowance	268		395
Quarter-to-date average recorded investment	6,894	7,646
Interest income recognized	38	39
Residential Portfolio Segment [Member] | Impaired Nonaccrual Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	3,854		2,660
Recorded investment with no allowance	2,083		678
Recorded investment with an allowance	1,367		1,797
Related allowance	94		215
Quarter-to-date average recorded investment	2,871	3,338
Residential Portfolio Segment [Member] | Impaired Accruing Restructured Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	4,013		4,041
Recorded investment with no allowance	2,563		2,583
Recorded investment with an allowance	1,450		1,458
Related allowance	174		180
Quarter-to-date average recorded investment	4,023	4,308
Interest income recognized	38	39
Residential Portfolio Segment [Member] | Other Impaired Accruing Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	189		556
Recorded investment with no allowance	189		556
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	11,857		12,431
Recorded investment with no allowance	10,429		9,198
Recorded investment with an allowance	732		2,808
Related allowance	85		580
Quarter-to-date average recorded investment	10,758	12,868
Interest income recognized	24	39
Commercial Real Estate Portfolio Segment [Member] | Impaired Nonaccrual Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	7,932		8,242
Recorded investment with no allowance	7,169		5,680
Recorded investment with an allowance	67		2,137
Related allowance	67		561
Quarter-to-date average recorded investment	7,352	9,318
Commercial Real Estate Portfolio Segment [Member] | Impaired Accruing Restructured Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	3,393		3,419
Recorded investment with no allowance	2,728		2,748
Recorded investment with an allowance	665		671
Related allowance	18		19
Quarter-to-date average recorded investment	3,406	3,550
Interest income recognized	24	39
Commercial Real Estate Portfolio Segment [Member] | Other Impaired Accruing Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	532		770
Recorded investment with no allowance	532		770
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	684		421
Recorded investment with no allowance	557		298
Quarter-to-date average recorded investment	382	325
Commercial Portfolio Segment [Member] | Impaired Nonaccrual Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	684		421
Recorded investment with no allowance	557		298
Quarter-to-date average recorded investment	382	325
Construction Loans [Member] | Commercial and Residential Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	335		41
Recorded investment with no allowance	335		41
Quarter-to-date average recorded investment	138	2,841
Interest income recognized	1	7
Construction Loans [Member] | Commercial and Residential Real Estate Portfolio Segment [Member] | Impaired Nonaccrual Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	297
Recorded investment with no allowance	297
Quarter-to-date average recorded investment	99	2,791
Construction Loans [Member] | Commercial and Residential Real Estate Portfolio Segment [Member] | Impaired Accruing Restructured Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	38		41
Recorded investment with no allowance	38		$ 41
Quarter-to-date average recorded investment	39	50
Interest income recognized	$ 1	$ 7