Loans (Credit Quality Indicators Vintage) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	$ 279,628	$ 1,058,859
Term loans amortized cost, prior year	973,956	734,581
Term loans amortized cost, two years ago	701,571	554,968
Term loans amortized cost, three years ago	497,658	476,043
Term loans amortized cost, four years ago	431,071	325,496
Term loans amortized cost, five years ago or more	967,209	699,479
Revolving loans amortized cost	328,623	330,433
Revolving loans converted to term loans	14,950	16,131
Total	4,194,666	4,195,990
Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	54,899	285,054
Term loans amortized cost, prior year	286,378	374,110
Term loans amortized cost, two years ago	369,807	300,304
Term loans amortized cost, three years ago	263,390	252,532
Term loans amortized cost, four years ago	235,088	147,808
Term loans amortized cost, five years ago or more	398,124	259,726
Revolving loans amortized cost	8,494	11,104
Revolving loans converted to term loans	2,360	2,386
Total	1,618,540	1,633,024
Commercial Real Estate | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	54,899	283,341
Term loans amortized cost, prior year	284,731	353,875
Term loans amortized cost, two years ago	340,081	260,917
Term loans amortized cost, three years ago	223,920	236,310
Term loans amortized cost, four years ago	218,914	136,490
Term loans amortized cost, five years ago or more	374,800	249,359
Revolving loans amortized cost	7,767	10,333
Revolving loans converted to term loans	2,360	2,386
Total	1,507,472	1,533,011
Commercial Real Estate | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	0	756
Term loans amortized cost, prior year	689	20,235
Term loans amortized cost, two years ago	29,726	39,387
Term loans amortized cost, three years ago	39,470	16,222
Term loans amortized cost, four years ago	16,174	11,318
Term loans amortized cost, five years ago or more	23,324	10,367
Revolving loans amortized cost	727	771
Revolving loans converted to term loans	0	0
Total	110,110	99,056
Commercial Real Estate | Classified [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	0	957
Term loans amortized cost, prior year	958	0
Term loans amortized cost, two years ago	0	0
Term loans amortized cost, three years ago	0	0
Term loans amortized cost, four years ago	0	0
Term loans amortized cost, five years ago or more	0	0
Revolving loans amortized cost	0	0
Revolving loans converted to term loans	0	0
Total	958	957
Commercial & Industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	99,420	295,019
Term loans amortized cost, prior year	235,011	96,497
Term loans amortized cost, two years ago	94,587	101,356
Term loans amortized cost, three years ago	99,970	63,631
Term loans amortized cost, four years ago	61,703	47,586
Term loans amortized cost, five years ago or more	148,001	112,344
Revolving loans amortized cost	100,656	99,623
Revolving loans converted to term loans	1,237	1,352
Total	840,585	817,408
Commercial & Industrial | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	99,420	293,493
Term loans amortized cost, prior year	233,508	95,775
Term loans amortized cost, two years ago	93,874	98,146
Term loans amortized cost, three years ago	95,248	56,792
Term loans amortized cost, four years ago	55,001	44,445
Term loans amortized cost, five years ago or more	128,130	91,128
Revolving loans amortized cost	96,981	95,817
Revolving loans converted to term loans	1,237	1,296
Total	803,399	776,892
Commercial & Industrial | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	0	1,123
Term loans amortized cost, prior year	1,105	722
Term loans amortized cost, two years ago	713	3,210
Term loans amortized cost, three years ago	4,722	6,839
Term loans amortized cost, four years ago	6,702	3,141
Term loans amortized cost, five years ago or more	13,508	14,853
Revolving loans amortized cost	3,675	3,806
Revolving loans converted to term loans	0	56
Total	30,425	33,750
Commercial & Industrial | Classified [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	0	403
Term loans amortized cost, prior year	398	0
Term loans amortized cost, two years ago	0	0
Term loans amortized cost, three years ago	0	0
Term loans amortized cost, four years ago	0	0
Term loans amortized cost, five years ago or more	6,363	6,363
Revolving loans amortized cost	0	0
Revolving loans converted to term loans	0	0
Total	6,761	6,766
Residential Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	119,706	463,715
Term loans amortized cost, prior year	438,727	254,926
Term loans amortized cost, two years ago	229,276	148,149
Term loans amortized cost, three years ago	129,592	156,862
Term loans amortized cost, four years ago	131,562	128,249
Term loans amortized cost, five years ago or more	408,627	315,411
Revolving loans amortized cost	0	0
Revolving loans converted to term loans	0	0
Total	1,457,490	1,467,312
Residential Real Estate | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	119,706	463,477
Term loans amortized cost, prior year	438,489	253,228
Term loans amortized cost, two years ago	227,838	146,839
Term loans amortized cost, three years ago	128,283	155,976
Term loans amortized cost, four years ago	130,769	128,139
Term loans amortized cost, five years ago or more	402,744	309,314
Revolving loans amortized cost	0	0
Revolving loans converted to term loans	0	0
Total	1,447,829	1,456,973
Residential Real Estate | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	0	238
Term loans amortized cost, prior year	238	1,698
Term loans amortized cost, two years ago	1,438	1,310
Term loans amortized cost, three years ago	1,309	886
Term loans amortized cost, four years ago	793	110
Term loans amortized cost, five years ago or more	5,883	6,097
Revolving loans amortized cost	0	0
Revolving loans converted to term loans	0	0
Total	9,661	10,339
Home Equity
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	1,791	9,838
Term loans amortized cost, prior year	8,710	6,806
Term loans amortized cost, two years ago	6,097	3,922
Term loans amortized cost, three years ago	3,559	1,474
Term loans amortized cost, four years ago	1,222	1,217
Term loans amortized cost, five years ago or more	4,855	4,141
Revolving loans amortized cost	219,213	219,395
Revolving loans converted to term loans	11,352	12,392
Total	256,799	259,185
Home Equity | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	1,791	9,838
Term loans amortized cost, prior year	8,710	6,771
Term loans amortized cost, two years ago	6,097	3,898
Term loans amortized cost, three years ago	3,535	1,474
Term loans amortized cost, four years ago	1,222	1,217
Term loans amortized cost, five years ago or more	4,787	3,955
Revolving loans amortized cost	219,028	219,085
Revolving loans converted to term loans	10,498	11,280
Total	255,668	257,518
Home Equity | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	0	0
Term loans amortized cost, prior year	0	35
Term loans amortized cost, two years ago	0	24
Term loans amortized cost, three years ago	24	0
Term loans amortized cost, four years ago	0	0
Term loans amortized cost, five years ago or more	68	186
Revolving loans amortized cost	185	310
Revolving loans converted to term loans	854	1,112
Total	1,131	1,667
Other
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	3,812	5,233
Term loans amortized cost, prior year	5,130	2,242
Term loans amortized cost, two years ago	1,804	1,237
Term loans amortized cost, three years ago	1,147	1,544
Term loans amortized cost, four years ago	1,496	636
Term loans amortized cost, five years ago or more	7,602	7,857
Revolving loans amortized cost	260	311
Revolving loans converted to term loans	1	1
Total	21,252	19,061
Other | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	3,799	5,214
Term loans amortized cost, prior year	5,119	2,241
Term loans amortized cost, two years ago	1,804	1,237
Term loans amortized cost, three years ago	1,147	1,544
Term loans amortized cost, four years ago	1,489	548
Term loans amortized cost, five years ago or more	7,514	7,850
Revolving loans amortized cost	260	308
Revolving loans converted to term loans	1	1
Total	21,133	18,943
Other | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year	13	19
Term loans amortized cost, prior year	11	1
Term loans amortized cost, two years ago	0	0
Term loans amortized cost, three years ago	0	0
Term loans amortized cost, four years ago	7	88
Term loans amortized cost, five years ago or more	88	7
Revolving loans amortized cost	0	3
Revolving loans converted to term loans	0	0
Total	$ 119	$ 118