Allowance for Credit Losses - Loan Balances by Year of Origination and Performing and Nonperforming Status (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
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	637,499	1,380,089
Year two	1,267,784	771,819
Year three	667,355	940,641
Year four	839,552	602,938
Year five	517,372	421,125
More than five years	1,691,803	1,564,501
Revolving	1,361,217	1,224,949
Revolving-Term	26,537	27,638
Total	7,009,119	6,933,699
Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	41
Year two	0	964
Year three	1,046	20,430
Year four	3,486	4,032
Year five	2,763	10,599
More than five years	23,019	27,478
Revolving	440	1,976
Revolving-Term	1,021	770
Total	31,775	66,291
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 real estate | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	179,496	385,347
Year two	362,454	317,359
Year three	297,630	461,613
Year four	451,998	332,482
Year five	307,380	259,723
More than five years	989,515	865,567
Revolving	22,509	36,948
Revolving-Term	0	0
Total	2,610,982	2,659,039
Commercial Loans | Commercial real estate | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0
Year three	0	7,107
Year four	2,400	2,261
Year five	609	6,296
More than five years	12,013	15,824
Revolving	0	0
Revolving-Term	0	0
Total	15,022	31,488
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 and industrial | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	100,561	437,529
Year two	340,495	126,371
Year three	101,459	123,944
Year four	99,768	86,852
Year five	74,087	38,540
More than five years	147,634	136,427
Revolving	615,240	548,622
Revolving-Term	0	0
Total	1,479,244	1,498,285
Commercial Loans | Commercial and industrial | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	10,473
Year four	0	60
Year five	57	2,882
More than five years	55	43
Revolving	230	1,780
Revolving-Term	0	0
Total	342	15,239
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 | Commercial construction | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	56,592	142,321
Year two	153,742	110,562
Year three	65,974	111,445
Year four	77,767	16,838
Year five	4,660	989
More than five years	9,145	10,093
Revolving	26,591	30,036
Revolving-Term	0	0
Total	394,471	422,284
Commercial Loans | Commercial construction | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	2,087
Year four	480	0
Year five	0	0
More than five years	384	384
Revolving	0	0
Revolving-Term	0	0
Total	864	2,471
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 | Business banking | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	142,538	257,368
Year two	249,086	107,984
Year three	99,139	144,689
Year four	126,702	113,820
Year five	96,028	81,195
More than five years	329,746	311,673
Revolving	108,530	108,202
Revolving-Term	1,114	1,122
Total	1,152,883	1,126,052
Commercial Loans | Business banking | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	41
Year two	0	64
Year three	0	287
Year four	355	1,408
Year five	1,858	694
More than five years	5,464	7,062
Revolving	102	28
Revolving-Term	128	57
Total	7,907	9,641
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 | Consumer real estate | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	146,070	137,465
Year two	148,208	100,253
Year three	96,073	91,689
Year four	78,369	49,853
Year five	33,317	39,657
More than five years	214,842	234,297
Revolving	511,065	443,238
Revolving-Term	23,924	23,839
Total	1,251,868	1,120,291
Consumer Loans | Consumer real estate | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	742
Year three	921	476
Year four	251	303
Year five	239	727
More than five years	4,972	4,165
Revolving	108	168
Revolving-Term	893	713
Total	7,384	7,294
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 | Other Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	12,242	20,059
Year two	13,799	9,290
Year three	7,080	7,261
Year four	4,948	3,093
Year five	1,900	1,021
More than five years	921	6,444
Revolving	77,282	57,903
Revolving-Term	1,499	2,677
Total	119,671	107,748
Consumer Loans | Other Consumer | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	158
Year three	125	0
Year four	0	0
Year five	0	0
More than five years	131	0
Revolving	0	0
Revolving-Term	0	0
Total	$ 256	$ 158