Allowance for Credit Losses - Loan Balances by Year of Origination and Internally Assigned Risk Rating (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 637,499	$ 1,380,130
Year two	1,267,784	772,783
Year three	668,401	961,071
Year four	843,038	606,970
Year five	520,135	431,724
More than five years	1,714,822	1,591,979
Revolving	1,361,657	1,226,925
Revolving-Term	27,558	28,408
Total	7,040,894	6,999,990
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	637,460	1,379,856
Year two	1,264,318	768,961
Year three	661,700	879,574
Year four	777,803	576,166
Year five	485,850	370,013
More than five years	1,473,625	1,361,826
Revolving	1,334,907	1,209,363
Revolving-Term	23,901	24,964
Total	6,659,564	6,570,723
Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	150
Year two	134	151
Year three	250	42,832
Year four	34,448	10,312
Year five	12,548	41,574
More than five years	127,631	88,094
Revolving	7,900	9,047
Revolving-Term	110	111
Total	183,021	192,271
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	39	124
Year two	3,332	3,671
Year three	6,451	36,888
Year four	30,787	20,492
Year five	21,737	20,137
More than five years	113,556	142,059
Revolving	18,850	8,515
Revolving-Term	3,547	3,333
Total	198,299	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	10	0
Revolving	0	0
Revolving-Term	0	0
Total	10	1,777
Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,297,126	5,406,584
Commercial Loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	179,496	385,347
Year two	362,454	317,359
Year three	297,630	468,720
Year four	454,398	334,743
Year five	307,989	266,019
More than five years	1,001,528	881,391
Revolving	22,509	36,948
Revolving-Term	0	0
Total	2,626,004	2,690,528
Commercial Loans | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	100,561	437,529
Year two	340,495	126,371
Year three	101,459	134,417
Year four	99,768	86,912
Year five	74,144	41,422
More than five years	147,689	136,470
Revolving	615,470	550,402
Revolving-Term	0	0
Total	1,479,586	1,513,523
Commercial Loans | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	56,592	142,321
Year two	153,742	110,562
Year three	65,974	113,532
Year four	78,247	16,838
Year five	4,660	989
More than five years	9,529	10,477
Revolving	26,591	30,036
Revolving-Term	0	0
Total	395,335	424,755
Commercial Loans | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	142,538	257,409
Year two	249,086	108,048
Year three	99,139	144,976
Year four	127,057	115,228
Year five	97,886	81,889
More than five years	335,210	318,735
Revolving	108,632	108,230
Revolving-Term	1,242	1,179
Total	1,160,790	1,135,693
Commercial Loans | Pass | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	179,496	385,347
Year two	359,214	316,003
Year three	296,299	412,191
Year four	432,058	314,303
Year five	284,614	213,019
More than five years	804,236	698,992
Revolving	22,509	35,448
Revolving-Term	0	0
Total	2,378,426	2,375,303
Commercial Loans | Pass | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	100,561	437,483
Year two	340,453	126,371
Year three	101,459	115,359
Year four	81,813	83,030
Year five	70,673	37,176
More than five years	145,354	132,182
Revolving	589,993	536,554
Revolving-Term	0	0
Total	1,430,306	1,468,155
Commercial Loans | Pass | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	56,592	142,321
Year two	153,742	108,405
Year three	63,832	111,512
Year four	58,690	16,838
Year five	4,656	989
More than five years	3,222	3,539
Revolving	26,591	30,036
Revolving-Term	0	0
Total	367,325	413,640
Commercial Loans | Pass | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	142,538	257,264
Year two	248,994	107,791
Year three	96,053	141,411
Year four	121,959	110,586
Year five	91,817	79,187
More than five years	311,935	293,215
Revolving	108,301	107,093
Revolving-Term	538	443
Total	1,122,135	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	8,569	6,401
Year five	7,391	40,445
More than five years	116,973	75,938
Revolving	0	0
Revolving-Term	0	0
Total	132,933	160,570
Commercial Loans | Special mention | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	46
Year two	42	0
Year three	0	3,060
Year four	3,898	2,546
Year five	2,185	72
More than five years	215	832
Revolving	7,721	8,887
Revolving-Term	0	0
Total	14,061	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	19,077	0
Year five	0	0
More than five years	4,389	4,458
Revolving	0	0
Revolving-Term	0	0
Total	23,466	4,458
Commercial Loans | Special mention | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	104
Year two	92	151
Year three	250	1,986
Year four	2,904	1,365
Year five	2,972	1,057
More than five years	5,144	5,929
Revolving	179	160
Revolving-Term	110	111
Total	11,651	10,863
Commercial Loans | Substandard | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	3,240	1,356
Year three	1,331	18,743
Year four	13,771	14,039
Year five	15,984	12,555
More than five years	80,309	106,461
Revolving	0	1,500
Revolving-Term	0	0
Total	114,635	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	14,057	1,336
Year five	1,286	4,174
More than five years	2,120	3,456
Revolving	17,756	4,961
Revolving-Term	0	0
Total	35,219	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	2,142	2,020
Year four	480	0
Year five	4	0
More than five years	1,918	2,480
Revolving	0	0
Revolving-Term	0	0
Total	4,544	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	2,836	1,579
Year four	2,194	3,277
Year five	3,097	1,645
More than five years	18,131	19,591
Revolving	152	977
Revolving-Term	594	625
Total	27,004	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	10	0
Revolving	0	0
Revolving-Term	0	0
Total	10	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	1,743,768	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	146,070	137,465
Year two	148,208	100,995
Year three	96,994	92,165
Year four	78,620	50,156
Year five	33,556	40,384
More than five years	219,814	238,462
Revolving	511,173	443,406
Revolving-Term	24,817	24,552
Total	1,259,252	1,127,585
Consumer Loans | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	12,242	20,059
Year two	13,799	9,448
Year three	7,205	7,261
Year four	4,948	3,093
Year five	1,900	1,021
More than five years	1,052	6,444
Revolving	77,282	57,903
Revolving-Term	1,499	2,677
Total	119,927	107,906
Consumer Loans | Pass | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	146,031	137,465
Year two	148,128	100,995
Year three	96,856	91,981
Year four	78,335	48,531
Year five	32,192	39,029
More than five years	207,827	231,861
Revolving	510,231	442,530
Revolving-Term	21,874	23,391
Total	1,241,474	1,115,783
Consumer Loans | Pass | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	12,242	19,976
Year two	13,787	9,396
Year three	7,201	7,120
Year four	4,948	2,878
Year five	1,898	613
More than five years	1,051	2,037
Revolving	77,282	57,702
Revolving-Term	1,489	1,130
Total	119,898	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	910	937
Revolving	0	0
Revolving-Term	0	0
Total	910	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	39	0
Year two	80	0
Year three	138	184
Year four	285	1,625
Year five	1,364	1,355
More than five years	11,077	5,664
Revolving	942	876
Revolving-Term	2,943	1,161
Total	16,868	10,865
Consumer Loans | Substandard | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	83
Year two	12	52
Year three	4	141
Year four	0	215
Year five	2	408
More than five years	1	4,407
Revolving	0	201
Revolving-Term	10	1,547
Total	29	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