Allowance for Credit Losses - Loan Balances by Year of Origination and Internally Assigned Risk Rating (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 952,159	$ 1,380,130
Year two	1,250,192	772,783
Year three	614,941	961,071
Year four	782,546	606,970
Year five	474,779	431,724
More than five years	1,608,076	1,591,979
Revolving	1,387,431	1,226,925
Revolving-Term	26,792	28,408
Total	7,096,916	6,999,990
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	952,121	1,379,856
Year two	1,231,943	768,961
Year three	610,210	879,574
Year four	734,404	576,166
Year five	429,064	370,013
More than five years	1,388,217	1,361,826
Revolving	1,357,489	1,209,363
Revolving-Term	23,224	24,964
Total	6,726,672	6,570,723
Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	150
Year two	14,934	151
Year three	189	42,832
Year four	20,036	10,312
Year five	25,356	41,574
More than five years	131,736	88,094
Revolving	13,587	9,047
Revolving-Term	95	111
Total	205,933	192,271
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	38	124
Year two	3,315	3,671
Year three	4,542	36,888
Year four	28,106	20,492
Year five	20,359	20,137
More than five years	88,123	142,059
Revolving	16,355	8,515
Revolving-Term	3,473	3,333
Total	164,311	235,219
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	1,777
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	1,777
Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,239,648	5,406,584
Commercial Loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	228,599	385,347
Year two	366,573	317,359
Year three	279,472	468,720
Year four	454,921	334,743
Year five	273,477	266,019
More than five years	938,489	881,391
Revolving	21,051	36,948
Revolving-Term	0	0
Total	2,562,582	2,690,528
Commercial Loans | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	185,389	437,529
Year two	308,442	126,371
Year three	97,811	134,417
Year four	89,270	86,912
Year five	70,268	41,422
More than five years	146,865	136,470
Revolving	603,834	550,402
Revolving-Term	0	0
Total	1,501,879	1,513,523
Commercial Loans | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	83,458	142,321
Year two	171,331	110,562
Year three	43,840	113,532
Year four	38,514	16,838
Year five	4,331	989
More than five years	5,047	10,477
Revolving	28,758	30,036
Revolving-Term	0	0
Total	375,279	424,755
Commercial Loans | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	213,494	257,409
Year two	240,779	108,048
Year three	94,289	144,976
Year four	119,394	115,228
Year five	92,528	81,889
More than five years	307,630	318,735
Revolving	108,141	108,230
Revolving-Term	1,348	1,179
Total	1,177,603	1,135,693
Commercial Loans | Pass | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	228,599	385,347
Year two	363,347	316,003
Year three	278,153	412,191
Year four	432,862	314,303
Year five	238,351	213,019
More than five years	760,947	698,992
Revolving	21,051	35,448
Revolving-Term	0	0
Total	2,323,310	2,375,303
Commercial Loans | Pass | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	185,389	437,483
Year two	293,593	126,371
Year three	97,811	115,359
Year four	72,039	83,030
Year five	66,958	37,176
More than five years	137,693	132,182
Revolving	574,820	536,554
Revolving-Term	0	0
Total	1,428,303	1,468,155
Commercial Loans | Pass | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	83,458	142,321
Year two	171,331	108,405
Year three	43,840	111,512
Year four	32,949	16,838
Year five	4,331	989
More than five years	3,150	3,539
Revolving	28,758	30,036
Revolving-Term	0	0
Total	367,817	413,640
Commercial Loans | Pass | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	213,494	257,264
Year two	240,694	107,791
Year three	91,018	141,411
Year four	116,429	110,586
Year five	86,469	79,187
More than five years	287,074	293,215
Revolving	107,849	107,093
Revolving-Term	679	443
Total	1,143,706	1,096,990
Commercial Loans | Special mention | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	37,786
Year four	9,407	6,401
Year five	20,189	40,445
More than five years	118,852	75,938
Revolving	0	0
Revolving-Term	0	0
Total	148,448	160,570
Commercial Loans | Special mention | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	46
Year two	14,849	0
Year three	0	3,060
Year four	4,213	2,546
Year five	2,091	72
More than five years	7,193	832
Revolving	13,466	8,887
Revolving-Term	0	0
Total	41,812	15,443
Commercial Loans | Special mention | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	5,565	0
Year five	0	0
More than five years	0	4,458
Revolving	0	0
Revolving-Term	0	0
Total	5,565	4,458
Commercial Loans | Special mention | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	104
Year two	85	151
Year three	189	1,986
Year four	851	1,365
Year five	3,076	1,057
More than five years	4,796	5,929
Revolving	121	160
Revolving-Term	95	111
Total	9,213	10,863
Commercial Loans | Substandard | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	3,226	1,356
Year three	1,319	18,743
Year four	12,652	14,039
Year five	14,937	12,555
More than five years	58,690	106,461
Revolving	0	1,500
Revolving-Term	0	0
Total	90,824	154,654
Commercial Loans | Substandard | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	14,221
Year four	13,018	1,336
Year five	1,219	4,174
More than five years	1,979	3,456
Revolving	15,548	4,961
Revolving-Term	0	0
Total	31,764	28,148
Commercial Loans | Substandard | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	2,157
Year three	0	2,020
Year four	0	0
Year five	0	0
More than five years	1,897	2,480
Revolving	0	0
Revolving-Term	0	0
Total	1,897	6,657
Commercial Loans | Substandard | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	41
Year two	0	106
Year three	3,082	1,579
Year four	2,114	3,277
Year five	2,983	1,645
More than five years	15,760	19,591
Revolving	171	977
Revolving-Term	574	625
Total	24,684	27,841
Commercial Loans | Doubtful | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Commercial Loans | Doubtful | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	1,777
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	1,777
Commercial Loans | Doubtful | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Commercial Loans | Doubtful | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Consumer Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,857,268	1,593,406
Consumer Loans | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Total		357,900
Consumer Loans | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	224,092	137,465
Year two	151,021	100,995
Year three	93,140	92,165
Year four	76,389	50,156
Year five	32,776	40,384
More than five years	209,197	238,462
Revolving	542,184	443,406
Revolving-Term	24,166	24,552
Total	1,352,965	1,127,585
Consumer Loans | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	17,127	20,059
Year two	12,046	9,448
Year three	6,389	7,261
Year four	4,058	3,093
Year five	1,399	1,021
More than five years	848	6,444
Revolving	83,463	57,903
Revolving-Term	1,278	2,677
Total	126,608	107,906
Consumer Loans | Pass | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	224,054	137,465
Year two	150,932	100,995
Year three	93,003	91,981
Year four	76,097	48,531
Year five	31,556	39,029
More than five years	198,505	231,861
Revolving	541,548	442,530
Revolving-Term	21,267	23,391
Total	1,336,962	1,115,783
Consumer Loans | Pass | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	17,127	19,976
Year two	12,046	9,396
Year three	6,385	7,120
Year four	4,028	2,878
Year five	1,399	613
More than five years	848	2,037
Revolving	83,463	57,702
Revolving-Term	1,278	1,130
Total	126,574	100,852
Consumer Loans | Special mention | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	895	937
Revolving	0	0
Revolving-Term	0	0
Total	895	937
Consumer Loans | Special mention | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Consumer Loans | Substandard | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	38	0
Year two	89	0
Year three	137	184
Year four	292	1,625
Year five	1,220	1,355
More than five years	9,797	5,664
Revolving	636	876
Revolving-Term	2,899	1,161
Total	15,108	10,865
Consumer Loans | Substandard | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	83
Year two	0	52
Year three	4	141
Year four	30	215
Year five	0	408
More than five years	0	4,407
Revolving	0	201
Revolving-Term	0	1,547
Total	34	7,054
Consumer Loans | Doubtful | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Consumer Loans | Doubtful | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	$ 0	$ 0