Loans (Residential, Home Equity and Consumer Loans Based on Payment Activity) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 3,225,232		$ 3,081,973
Consumer Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	25,194
2019	21,679
2018	9,779
2017	2,878
2016	1,292
Prior	2,506
Revolving Loans Amortized Cost Basis	1,591
Total	64,919	$ 69,264	81,217
Consumer Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	25,189
2019	21,676
2018	9,777
2017	2,876
2016	1,292
Prior	2,444
Revolving Loans Amortized Cost Basis	1,560
Total	64,814
Consumer Loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
2020	5
2019	3
2018	2
2017	2
2016	0
Prior	62
Revolving Loans Amortized Cost Basis	31
Total	105
Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	34
2017	46
2016	68
Prior	425
Revolving Loans Amortized Cost Basis	218,067
Total	218,640	225,790	225,755
Home Equity Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	34
2017	46
2016	68
Prior	425
Revolving Loans Amortized Cost Basis	217,866
Total	218,439
Home Equity Loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	201
Total	201
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	27,378
2019	28,514
2018	33,281
2017	32,530
2016	29,788
Prior	110,948
Revolving Loans Amortized Cost Basis	0
Total	262,439	$ 305,002	$ 304,855
Residential Mortgage Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	27,378
2019	28,514
2018	33,281
2017	32,530
2016	29,701
Prior	109,972
Revolving Loans Amortized Cost Basis	0
Total	261,376
Residential Mortgage Loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	87
Prior	976
Revolving Loans Amortized Cost Basis	0
Total	$ 1,063