Loans and Allowance for Credit Losses - Loan Balances by Year of Origination and Performing and Nonperforming Status (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 875,940	$ 1,271,764
Year two	1,301,309	1,214,107
Year three	1,118,263	586,544
Year four	513,435	725,517
Year five	668,747	449,759
More than five years	1,712,993	1,528,088
Revolving	1,295,848	1,381,517
Revolving-Term	29,383	26,673
Total	7,515,918	7,183,969
Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	875,940	1,271,764
Year two	1,300,933	1,213,905
Year three	1,118,219	585,892
Year four	513,157	724,629
Year five	667,958	448,121
More than five years	1,704,170	1,513,912
Revolving	1,295,410	1,380,980
Revolving-Term	27,454	25,714
Total	7,503,241	7,164,917
Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	376	202
Year three	44	652
Year four	278	888
Year five	789	1,638
More than five years	8,823	14,176
Revolving	438	537
Revolving-Term	1,929	959
Total	12,677	19,052
Commercial Loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	221,775	292,732
Year two	268,261	360,423
Year three	422,345	269,049
Year four	245,339	449,493
Year five	426,370	261,941
More than five years	971,630	883,535
Revolving	35,469	21,666
Revolving-Term	0	0
Total	2,591,189	2,538,839
Commercial Loans | Commercial real estate | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	221,775	292,732
Year two	268,261	360,423
Year three	422,345	269,049
Year four	245,339	449,493
Year five	426,370	261,941
More than five years	970,368	876,435
Revolving	35,469	21,666
Revolving-Term	0	0
Total	2,589,927	2,531,739
Commercial Loans | Commercial real estate | Nonaccrual
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	1,262	7,100
Revolving	0	0
Revolving-Term	0	0
Total	1,262	7,100
Commercial Loans | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	143,170	253,696
Year two	235,058	289,448
Year three	224,893	88,544
Year four	58,238	73,998
Year five	59,273	65,911
More than five years	184,340	147,273
Revolving	519,169	591,522
Revolving-Term	0	0
Total	1,424,141	1,510,392
Commercial Loans | Commercial and industrial | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	143,170	253,696
Year two	235,058	289,448
Year three	224,893	88,544
Year four	58,238	73,998
Year five	59,273	65,858
More than five years	183,651	147,273
Revolving	518,939	591,292
Revolving-Term	0	0
Total	1,423,222	1,510,109
Commercial Loans | Commercial and industrial | Nonaccrual
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	53
More than five years	689	0
Revolving	230	230
Revolving-Term	0	0
Total	919	283
Commercial Loans | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	44,519	120,655
Year two	188,037	170,691
Year three	97,525	40,762
Year four	13,266	14,442
Year five	10,815	3,953
More than five years	6,202	4,176
Revolving	12,475	27,284
Revolving-Term	0	0
Total	372,839	381,963
Commercial Loans | Commercial construction | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	44,519	120,655
Year two	188,037	170,691
Year three	97,525	40,762
Year four	13,266	14,442
Year five	10,815	3,953
More than five years	5,818	3,792
Revolving	12,475	27,284
Revolving-Term	0	0
Total	372,455	381,579
Commercial Loans | Commercial construction | Nonaccrual
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	384	384
Revolving	0	0
Revolving-Term	0	0
Total	384	384
Commercial Loans | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	230,663	287,679
Year two	270,110	233,723
Year three	216,729	91,149
Year four	91,167	109,731
Year five	102,761	84,889
More than five years	351,469	292,211
Revolving	98,585	105,271
Revolving-Term	1,830	1,291
Total	1,363,314	1,205,944
Commercial Loans | Business banking | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	230,663	287,679
Year two	270,110	233,656
Year three	216,729	91,149
Year four	91,128	109,479
Year five	102,469	83,689
More than five years	347,909	289,435
Revolving	98,585	105,172
Revolving-Term	1,711	1,195
Total	1,359,304	1,201,454
Commercial Loans | Business banking | Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	67
Year three	0	0
Year four	39	252
Year five	292	1,200
More than five years	3,560	2,776
Revolving	0	99
Revolving-Term	119	96
Total	4,010	4,490
Consumer Loans | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	225,529	296,948
Year two	326,707	149,003
Year three	149,242	91,613
Year four	101,938	74,583
Year five	67,984	32,031
More than five years	198,475	200,169
Revolving	554,347	553,649
Revolving-Term	24,834	23,957
Total	1,649,056	1,421,953
Consumer Loans | Consumer real estate | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	225,529	296,948
Year two	326,331	148,868
Year three	149,205	91,085
Year four	101,895	73,947
Year five	67,487	31,646
More than five years	195,678	196,384
Revolving	554,139	553,441
Revolving-Term	23,024	23,108
Total	1,643,288	1,415,427
Consumer Loans | Consumer real estate | Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	376	135
Year three	37	528
Year four	43	636
Year five	497	385
More than five years	2,797	3,785
Revolving	208	208
Revolving-Term	1,810	849
Total	5,768	6,526
Consumer Loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	10,284	20,054
Year two	13,136	10,819
Year three	7,529	5,427
Year four	3,487	3,270
Year five	1,544	1,034
More than five years	877	724
Revolving	75,803	82,125
Revolving-Term	2,719	1,425
Total	115,379	124,878
Consumer Loans | Other consumer | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	10,284	20,054
Year two	13,136	10,819
Year three	7,522	5,303
Year four	3,291	3,270
Year five	1,544	1,034
More than five years	746	593
Revolving	75,803	82,125
Revolving-Term	2,719	1,411
Total	115,045	124,609
Consumer Loans | Other consumer | Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	7	124
Year four	196	0
Year five	0	0
More than five years	131	131
Revolving	0	0
Revolving-Term	0	14
Total	$ 334	$ 269