Allowance for Credit Losses - Amortized Cost Basis by Year of Origination and Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Credit quality
Total loans and leases	$ 12,961,999	$ 13,279,097	$ 13,211,650
Loss
Credit quality
Total loans and leases	0	0
Residential mortgage
Credit quality
2020/2021	1,304,978	864,559
2019/2020	753,668	482,495
2018/2019	363,415	389,725
2017/2018	266,368	471,962
2016/2017	332,041	391,156
Prior	1,062,135	1,089,580
Revolving Loans Amortized Cost Basis	44	578
Revolving Loans Converted to Term Loans Amortized Cost Basis	718	163
Total loans and leases	4,083,367	3,690,218
Residential mortgage | 740 and greater
Credit quality
2020/2021	1,101,958	728,807
2019/2020	635,061	384,248
2018/2019	286,993	290,484
2017/2018	198,622	361,297
2016/2017	251,906	314,971
Prior	829,175	830,795
Total loans and leases	3,303,715	2,910,602
Residential mortgage | 680 - 739
Credit quality
2020/2021	140,997	85,151
2019/2020	81,590	53,090
2018/2019	45,163	44,616
2017/2018	27,315	50,703
2016/2017	32,855	39,230
Prior	125,906	144,537
Total loans and leases	453,826	417,327
Residential mortgage | 620 - 679
Credit quality
2020/2021	15,781	15,767
2019/2020	11,943	7,604
2018/2019	5,268	11,460
2017/2018	10,149	9,628
2016/2017	9,069	7,982
Prior	37,404	43,393
Total loans and leases	89,614	95,834
Residential mortgage | 550 - 619
Credit quality
2020/2021	1,735
2019/2020	873	1,971
2018/2019	698	2,818
2017/2018	533	2,920
2016/2017	2,033	4,474
Prior	7,475	10,144
Total loans and leases	13,347	22,327
Residential mortgage | Less than 550
Credit quality
2019/2020		861
2018/2019		593
2017/2018	345	2,916
2016/2017	2,603	594
Prior	2,838	2,138
Total loans and leases	5,786	7,102
Residential mortgage | No Score
Credit quality
2020/2021	18,882	13,823
2019/2020	7,938	18,861
2018/2019	15,051	21,214
2017/2018	18,107	21,821
2016/2017	17,333	14,355
Prior	42,185	45,147
Total loans and leases	119,496	135,221
Residential mortgage | Fico Other
Credit quality
2020/2021	25,625	21,011
2019/2020	16,263	15,860
2018/2019	10,242	18,540
2017/2018	11,297	22,677
2016/2017	16,242	9,550
Prior	17,152	13,426
Revolving Loans Amortized Cost Basis	44	578
Revolving Loans Converted to Term Loans Amortized Cost Basis	718	163
Total loans and leases	97,583	101,805
Home equity
Credit quality
Revolving Loans Amortized Cost Basis		833,521
Revolving Loans Converted to Term Loans Amortized Cost Basis		8,103
Total loans and leases		841,624
Home equity | 740 and greater
Credit quality
Revolving Loans Amortized Cost Basis		608,282
Revolving Loans Converted to Term Loans Amortized Cost Basis		2,163
Total loans and leases		610,445
Home equity | 680 - 739
Credit quality
Revolving Loans Amortized Cost Basis		159,886
Revolving Loans Converted to Term Loans Amortized Cost Basis		3,155
Total loans and leases		163,041
Home equity | 620 - 679
Credit quality
Revolving Loans Amortized Cost Basis		44,005
Revolving Loans Converted to Term Loans Amortized Cost Basis		1,571
Total loans and leases		45,576
Home equity | 550 - 619
Credit quality
Revolving Loans Amortized Cost Basis		11,644
Revolving Loans Converted to Term Loans Amortized Cost Basis		884
Total loans and leases		12,528
Home equity | Less than 550
Credit quality
Revolving Loans Amortized Cost Basis		5,159
Revolving Loans Converted to Term Loans Amortized Cost Basis		330
Total loans and leases		5,489
Home equity | No Score
Credit quality
Revolving Loans Amortized Cost Basis		4,545
Total loans and leases		4,545
Consumer loans
Credit quality
2020/2021		250,019
2019/2020		295,128
2018/2019		226,757
2017/2018		139,788
2016/2017		62,534
Prior		25,576
Revolving Loans Amortized Cost Basis		349,158
Revolving Loans Converted to Term Loans Amortized Cost Basis		4,882
Total loans and leases		1,353,842
Consumer loans | 740 and greater
Credit quality
2020/2021		113,373
2019/2020		122,965
2018/2019		99,678
2017/2018		54,691
2016/2017		24,029
Prior		6,034
Revolving Loans Amortized Cost Basis		114,748
Revolving Loans Converted to Term Loans Amortized Cost Basis		275
Total loans and leases		535,793
Consumer loans | 680 - 739
Credit quality
2020/2021		83,316
2019/2020		90,853
2018/2019		66,143
2017/2018		36,426
2016/2017		16,358
Prior		4,985
Revolving Loans Amortized Cost Basis		76,391
Revolving Loans Converted to Term Loans Amortized Cost Basis		773
Total loans and leases		375,245
Consumer loans | 620 - 679
Credit quality
2020/2021		40,469
2019/2020		48,904
2018/2019		33,917
2017/2018		24,705
2016/2017		11,144
Prior		3,788
Revolving Loans Amortized Cost Basis		36,622
Revolving Loans Converted to Term Loans Amortized Cost Basis		1,221
Total loans and leases		200,770
Consumer loans | 550 - 619
Credit quality
2020/2021		9,125
2019/2020		20,274
2018/2019		17,693
2017/2018		15,126
2016/2017		7,825
Prior		2,883
Revolving Loans Amortized Cost Basis		12,980
Revolving Loans Converted to Term Loans Amortized Cost Basis		1,458
Total loans and leases		87,364
Consumer loans | Less than 550
Credit quality
2020/2021		3,017
2019/2020		10,139
2018/2019		9,189
2017/2018		6,517
2016/2017		3,123
Prior		1,118
Revolving Loans Amortized Cost Basis		5,261
Revolving Loans Converted to Term Loans Amortized Cost Basis		799
Total loans and leases		39,163
Consumer loans | No Score
Credit quality
2020/2021		339
2019/2020		103
2018/2019		64
2017/2018		109
2016/2017		10
Revolving Loans Amortized Cost Basis		33,854
Revolving Loans Converted to Term Loans Amortized Cost Basis		356
Total loans and leases		34,835
Consumer loans | Fico Other
Credit quality
2020/2021		380
2019/2020		1,890
2018/2019		73
2017/2018		2,214
2016/2017		45
Prior		6,768
Revolving Loans Amortized Cost Basis		69,302
Total loans and leases		80,672
Residential and consumer
Credit quality
2020/2021	3,157,488	2,543,705
2019/2020	1,588,735	2,120,213
2018/2019	1,632,764	1,644,201
2017/2018	1,164,714	1,291,172
2016/2017	954,259	882,520
Prior	2,359,432	2,236,923
Revolving Loans Amortized Cost Basis	2,033,383	2,516,240
Revolving Loans Converted to Term Loans Amortized Cost Basis	71,224	44,123
Total loans and leases	12,961,999	13,279,097
Residential Mortgage
Credit quality
Total loans and leases	4,083,367	3,690,218	4,662,175
Residential Mortgage | Home equity
Credit quality
2020/2021		864,559
2019/2020		482,495
2018/2019		389,725
2017/2018		471,962
2016/2017		391,156
Prior		1,089,580
Revolving Loans Amortized Cost Basis		834,099
Revolving Loans Converted to Term Loans Amortized Cost Basis		8,266
Total loans and leases		4,531,842
Home equity Line
Credit quality
Total loans and leases	876,608	841,624
Consumer
Credit quality
2020/2021	306,140
2019/2020	174,166
2018/2019	184,913
2017/2018	124,197
2016/2017	67,459
Prior	24,158
Revolving Loans Amortized Cost Basis	344,870
Revolving Loans Converted to Term Loans Amortized Cost Basis	4,036
Total loans and leases	1,229,939	1,353,842	1,620,556
Consumer | 740 and greater
Credit quality
2020/2021	155,929
2019/2020	83,337
2018/2019	79,617
2017/2018	56,707
2016/2017	24,525
Prior	8,067
Revolving Loans Amortized Cost Basis	117,843
Revolving Loans Converted to Term Loans Amortized Cost Basis	209
Total loans and leases	526,234
Consumer | 680 - 739
Credit quality
2020/2021	93,214
2019/2020	56,327
2018/2019	55,126
2017/2018	34,049
2016/2017	17,527
Prior	6,315
Revolving Loans Amortized Cost Basis	69,366
Revolving Loans Converted to Term Loans Amortized Cost Basis	707
Total loans and leases	332,631
Consumer | 620 - 679
Credit quality
2020/2021	41,671
2019/2020	21,986
2018/2019	28,491
2017/2018	19,403
2016/2017	12,952
Prior	5,324
Revolving Loans Amortized Cost Basis	31,165
Revolving Loans Converted to Term Loans Amortized Cost Basis	1,175
Total loans and leases	162,167
Consumer | 550 - 619
Credit quality
2020/2021	7,836
2019/2020	8,265
2018/2019	13,265
2017/2018	10,497
2016/2017	7,469
Prior	3,244
Revolving Loans Amortized Cost Basis	10,359
Revolving Loans Converted to Term Loans Amortized Cost Basis	1,089
Total loans and leases	62,024
Consumer | Less than 550
Credit quality
2020/2021	2,272
2019/2020	3,867
2018/2019	6,646
2017/2018	3,484
2016/2017	2,739
Prior	1,175
Revolving Loans Amortized Cost Basis	3,195
Revolving Loans Converted to Term Loans Amortized Cost Basis	536
Total loans and leases	23,914
Consumer | No Score
Credit quality
2020/2021	481
2019/2020	19
2018/2019	56
2017/2018	40
2016/2017	65
Prior	2
Revolving Loans Amortized Cost Basis	35,414
Revolving Loans Converted to Term Loans Amortized Cost Basis	320
Total loans and leases	36,397
Consumer | Fico Other
Credit quality
2020/2021	4,737
2019/2020	365
2018/2019	1,712
2017/2018	17
2016/2017	2,182
Prior	31
Revolving Loans Amortized Cost Basis	77,528
Total loans and leases	86,572
Residential Mortgage.
Credit quality
2020/2021	1,304,978
2019/2020	753,668
2018/2019	363,415
2017/2018	266,368
2016/2017	332,041
Prior	1,062,135
Revolving Loans Amortized Cost Basis	867,295
Revolving Loans Converted to Term Loans Amortized Cost Basis	10,075
Total loans and leases	4,959,975
Home Equity Loans and Lines of Credit
Credit quality
Revolving Loans Amortized Cost Basis	867,251
Revolving Loans Converted to Term Loans Amortized Cost Basis	9,357
Total loans and leases	876,608
Home Equity Loans and Lines of Credit | 740 and greater
Credit quality
Revolving Loans Amortized Cost Basis	671,566
Revolving Loans Converted to Term Loans Amortized Cost Basis	1,873
Total loans and leases	673,439
Home Equity Loans and Lines of Credit | 680 - 739
Credit quality
Revolving Loans Amortized Cost Basis	141,889
Revolving Loans Converted to Term Loans Amortized Cost Basis	3,968
Total loans and leases	145,857
Home Equity Loans and Lines of Credit | 620 - 679
Credit quality
Revolving Loans Amortized Cost Basis	37,815
Revolving Loans Converted to Term Loans Amortized Cost Basis	2,500
Total loans and leases	40,315
Home Equity Loans and Lines of Credit | 550 - 619
Credit quality
Revolving Loans Amortized Cost Basis	9,090
Revolving Loans Converted to Term Loans Amortized Cost Basis	948
Total loans and leases	10,038
Home Equity Loans and Lines of Credit | Less than 550
Credit quality
Revolving Loans Amortized Cost Basis	2,574
Revolving Loans Converted to Term Loans Amortized Cost Basis	68
Total loans and leases	2,642
Home Equity Loans and Lines of Credit | No Score
Credit quality
Revolving Loans Amortized Cost Basis	4,317
Total loans and leases	4,317
Commercial and Industrial
Credit quality
2020/2021	637,126	931,522
2019/2020	142,497	349,849
2018/2019	237,293	215,307
2017/2018	106,699	81,113
2016/2017	32,409	56,095
Prior	177,825	111,069
Revolving Loans Amortized Cost Basis	711,028	1,243,900
Revolving Loans Converted to Term Loans Amortized Cost Basis	42,222	30,652
Total loans and leases	2,087,099	3,019,507	2,743,242
Commercial and Industrial | Pass
Credit quality
2020/2021	623,098	873,639
2019/2020	129,665	324,030
2018/2019	223,388	183,329
2017/2018	88,409	73,000
2016/2017	29,380	49,886
Prior	168,591	94,360
Revolving Loans Amortized Cost Basis	644,947	1,058,786
Revolving Loans Converted to Term Loans Amortized Cost Basis	40,193	28,853
Total loans and leases	1,947,671	2,685,883
Commercial and Industrial | Special mention
Credit quality
2020/2021	397	20,937
2019/2020	4,382	10,370
2018/2019	4,213	20,164
2017/2018	12,552	2,099
2016/2017	974	279
Prior	5,313	8,316
Revolving Loans Amortized Cost Basis	4,804	101,183
Revolving Loans Converted to Term Loans Amortized Cost Basis	986	1,549
Total loans and leases	33,621	164,897
Commercial and Industrial | Substandard
Credit quality
2020/2021	354	23,804
2019/2020	1,380	2,023
2018/2019	1,951	2,568
2017/2018	1,285	677
2016/2017	60	4,063
Prior	3,551	8,113
Revolving Loans Amortized Cost Basis	17,893	33,775
Revolving Loans Converted to Term Loans Amortized Cost Basis	1,043	250
Total loans and leases	27,517	75,273
Commercial and Industrial | Other Indicator
Credit quality
2020/2021	13,277	13,142
2019/2020	7,070	13,426
2018/2019	7,741	9,246
2017/2018	4,453	5,337
2016/2017	1,995	1,867
Prior	370	280
Revolving Loans Amortized Cost Basis	43,384	50,156
Total loans and leases	78,290	93,454
Commercial real estate
Credit quality
2020/2021	693,370	344,374
2019/2020	338,140	678,824
2018/2019	582,386	586,274
2017/2018	496,985	484,627
2016/2017	440,863	343,882
Prior	986,450	894,258
Revolving Loans Amortized Cost Basis	86,538	60,114
Revolving Loans Converted to Term Loans Amortized Cost Basis	14,891	323
Total loans and leases	3,639,623	3,392,676	3,463,953
Commercial real estate | Pass
Credit quality
2020/2021	693,370	342,845
2019/2020	338,140	611,243
2018/2019	533,887	541,104
2017/2018	487,739	447,366
2016/2017	415,186	295,426
Prior	940,732	814,398
Revolving Loans Amortized Cost Basis	78,479	47,604
Revolving Loans Converted to Term Loans Amortized Cost Basis	14,891	323
Total loans and leases	3,502,424	3,100,309
Commercial real estate | Special mention
Credit quality
2020/2021		1,500
2019/2020		63,617
2018/2019	48,499	26,187
2017/2018	7,470	33,482
2016/2017	25,513	37,841
Prior	30,255	61,279
Revolving Loans Amortized Cost Basis	7,600	2,999
Total loans and leases	119,337	226,905
Commercial real estate | Substandard
Credit quality
2020/2021		29
2019/2020		3,964
2018/2019		18,983
2017/2018	1,776	3,779
2016/2017	164	10,615
Prior	15,303	18,083
Revolving Loans Amortized Cost Basis	459	9,511
Total loans and leases	17,702	64,964
Commercial real estate | Other Indicator
Credit quality
Prior	160	498
Total loans and leases	160	498
Construction
Credit quality
2020/2021	181,393	70,509
2019/2020	116,642	250,631
2018/2019	214,875	211,831
2017/2018	160,689	94,034
2016/2017	65,454	25,492
Prior	51,264	54,353
Revolving Loans Amortized Cost Basis	23,652	28,969
Total loans and leases	813,969	735,819	519,241
Construction | Pass
Credit quality
2020/2021	154,558	53,931
2019/2020	107,767	233,730
2018/2019	210,314	202,808
2017/2018	155,311	83,792
2016/2017	62,770	23,171
Prior	48,021	41,536
Revolving Loans Amortized Cost Basis	22,859	28,386
Total loans and leases	761,600	667,354
Construction | Special mention
Credit quality
2019/2020		508
2018/2019	244	707
2017/2018	707	4,717
Prior	356	9,172
Total loans and leases	1,307	15,104
Construction | Substandard
Credit quality
2018/2019		541
2017/2018	363	1,840
2016/2017		521
Prior	839	989
Total loans and leases	1,202	3,891
Construction | Other Indicator
Credit quality
2020/2021	26,835	16,578
2019/2020	8,875	16,393
2018/2019	4,317	7,775
2017/2018	4,308	3,685
2016/2017	2,684	1,800
Prior	2,048	2,656
Revolving Loans Amortized Cost Basis	793	583
Total loans and leases	49,860	49,470
Lease financing
Credit quality
2020/2021	34,481	82,722
2019/2020	63,622	63,286
2018/2019	49,882	14,307
2017/2018	9,776	19,648
2016/2017	16,033	3,361
Prior	57,600	62,087
Total loans and leases	231,394	245,411	$ 202,483
Lease financing | Pass
Credit quality
2020/2021	33,980	79,064
2019/2020	60,650	60,717
2018/2019	48,236	13,669
2017/2018	9,449	17,207
2016/2017	15,009	3,010
Prior	57,130	61,266
Total loans and leases	224,454	234,933
Lease financing | Special mention
Credit quality
2020/2021	501	950
2019/2020	2,702	892
2018/2019	1,506	311
2017/2018	311	1,300
2016/2017	153	351
Prior		295
Total loans and leases	5,173	4,099
Lease financing | Substandard
Credit quality
2020/2021		2,708
2019/2020	270	1,677
2018/2019	140	327
2017/2018	16	1,141
2016/2017	871
Prior	470	526
Total loans and leases	1,767	6,379
Commercial Lending
Credit quality
2020/2021	1,546,370	1,429,127
2019/2020	660,901	1,342,590
2018/2019	1,084,436	1,027,719
2017/2018	774,149	679,422
2016/2017	554,759	428,830
Prior	1,273,139	1,121,767
Revolving Loans Amortized Cost Basis	821,218	1,332,983
Revolving Loans Converted to Term Loans Amortized Cost Basis	57,113	30,975
Total loans and leases	$ 6,772,085	$ 7,393,413