Loans and Allowance for Credit Losses - Loan Balances by Year of Origination and Performing and Nonperforming Status (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 532,634	$ 1,117,436
Year two	1,165,227	1,320,936
Year three	1,263,568	1,094,225
Year four	942,600	503,703
Year five	451,252	645,502
More than five years	2,036,020	1,650,211
Revolving	1,263,917	1,292,135
Revolving-Term	33,836	29,193
Total	7,689,054	7,653,341
Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	532,634	1,117,436
Year two	1,164,529	1,320,560
Year three	1,262,354	1,094,056
Year four	942,496	502,950
Year five	450,303	640,393
More than five years	2,012,919	1,635,979
Revolving	1,259,745	1,291,683
Revolving-Term	32,185	27,337
Total	7,657,165	7,630,394
Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	698	376
Year three	1,214	169
Year four	104	753
Year five	949	5,109
More than five years	23,101	14,232
Revolving	4,172	452
Revolving-Term	1,651	1,856
Total	31,889	22,947
Commercial Loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	122,012	276,677
Year two	287,445	324,469
Year three	369,944	439,308
Year four	412,477	240,256
Year five	218,149	419,371
More than five years	1,217,037	926,636
Revolving	33,752	32,418
Revolving-Term	0	0
Total	2,660,816	2,659,135
Commercial Loans | Commercial real estate | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	122,012	276,677
Year two	287,445	324,469
Year three	368,955	439,308
Year four	412,477	240,256
Year five	218,149	419,371
More than five years	1,203,855	920,316
Revolving	33,752	32,418
Revolving-Term	0	0
Total	2,646,645	2,652,815
Commercial Loans | Commercial real estate | Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	989	0
Year four	0	0
Year five	0	0
More than five years	13,182	6,320
Revolving	0	0
Revolving-Term	0	0
Total	14,171	6,320
Commercial Loans | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	61,621	171,861
Year two	168,934	231,978
Year three	217,452	210,636
Year four	162,667	54,696
Year five	42,312	52,858
More than five years	206,647	193,905
Revolving	503,844	520,249
Revolving-Term	0	0
Total	1,363,477	1,436,183
Commercial Loans | Commercial and industrial | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	61,621	171,861
Year two	168,895	231,978
Year three	217,452	210,636
Year four	162,567	54,696
Year five	42,312	52,858
More than five years	206,647	193,257
Revolving	500,681	520,019
Revolving-Term	0	0
Total	1,360,175	1,435,305
Commercial Loans | Commercial and industrial | Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	39	0
Year three	0	0
Year four	100	0
Year five	0	0
More than five years	0	648
Revolving	3,163	230
Revolving-Term	0	0
Total	3,302	878
Commercial Loans | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	70,752	75,596
Year two	116,904	154,456
Year three	115,703	82,313
Year four	44,394	14,845
Year five	12,579	4,727
More than five years	6,274	4,438
Revolving	7,693	14,208
Revolving-Term	0	0
Total	374,299	350,583
Commercial Loans | Commercial construction | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	70,752	75,596
Year two	116,904	154,456
Year three	115,703	82,313
Year four	44,394	14,845
Year five	12,579	151
More than five years	2,858	4,054
Revolving	7,693	14,208
Revolving-Term	0	0
Total	370,883	345,623
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	4,576
More than five years	3,416	384
Revolving	0	0
Revolving-Term	0	0
Total	3,416	4,960
Commercial Loans | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	103,628	270,129
Year two	244,309	262,606
Year three	225,878	207,611
Year four	179,543	88,018
Year five	78,867	99,574
More than five years	369,124	334,766
Revolving	88,495	96,754
Revolving-Term	1,236	1,307
Total	1,291,080	1,360,765
Commercial Loans | Business banking | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	103,628	270,129
Year two	244,123	262,606
Year three	225,653	207,611
Year four	179,543	87,979
Year five	78,694	99,354
More than five years	365,840	330,902
Revolving	88,495	96,754
Revolving-Term	1,201	1,283
Total	1,287,177	1,356,618
Commercial Loans | Business banking | Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	186	0
Year three	225	0
Year four	0	39
Year five	173	220
More than five years	3,284	3,864
Revolving	0	0
Revolving-Term	35	24
Total	3,903	4,147
Consumer Loans | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	167,541	311,887
Year two	339,911	335,462
Year three	326,286	147,850
Year four	139,497	102,041
Year five	97,115	67,890
More than five years	236,193	189,794
Revolving	560,726	552,080
Revolving-Term	26,878	24,774
Total	1,894,147	1,731,778
Consumer Loans | Consumer real estate | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	167,541	311,887
Year two	339,438	335,086
Year three	326,286	147,689
Year four	139,497	101,518
Year five	96,453	67,577
More than five years	233,120	186,909
Revolving	559,717	551,858
Revolving-Term	25,262	22,942
Total	1,887,314	1,725,466
Consumer Loans | Consumer real estate | Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	473	376
Year three	0	161
Year four	0	523
Year five	662	313
More than five years	3,073	2,885
Revolving	1,009	222
Revolving-Term	1,616	1,832
Total	6,833	6,312
Consumer Loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	7,080	11,286
Year two	7,724	11,965
Year three	8,305	6,507
Year four	4,022	3,847
Year five	2,230	1,082
More than five years	745	672
Revolving	69,407	76,426
Revolving-Term	5,722	3,112
Total	105,235	114,897
Consumer Loans | Other consumer | Accrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	7,080	11,286
Year two	7,724	11,965
Year three	8,305	6,499
Year four	4,018	3,656
Year five	2,116	1,082
More than five years	599	541
Revolving	69,407	76,426
Revolving-Term	5,722	3,112
Total	104,971	114,567
Consumer Loans | Other consumer | Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	8
Year four	4	191
Year five	114	0
More than five years	146	131
Revolving	0	0
Revolving-Term	0	0
Total	$ 264	$ 330