Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans Segregated by Class of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Total	$ 7,653,341	$ 7,183,969
Nonaccrual	22,947	19,052	$ 66,291
Current
Financing Receivable, Past Due [Line Items]
Total	7,615,273	7,144,576
Total Past Due Loans
Financing Receivable, Past Due [Line Items]
Total	38,068	39,393
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	7,247	18,093
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	7,874	2,248
Commercial Loans | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total	2,659,135	2,538,839
Nonaccrual	6,320	7,100	31,488
Commercial Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total	1,436,183	1,510,392
Nonaccrual	878	283	15,239
Commercial Loans | Commercial construction
Financing Receivable, Past Due [Line Items]
Total	350,583	381,963
Nonaccrual	4,960	384	2,471
Commercial Loans | Business banking
Financing Receivable, Past Due [Line Items]
Total	1,360,765	1,205,944
Nonaccrual	4,147	4,490	9,641
Commercial Loans | Current | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total	2,649,412	2,523,315
Commercial Loans | Current | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total	1,435,301	1,505,805
Commercial Loans | Current | Commercial construction
Financing Receivable, Past Due [Line Items]
Total	345,623	381,579
Commercial Loans | Current | Business banking
Financing Receivable, Past Due [Line Items]
Total	1,351,048	1,199,586
Commercial Loans | Total Past Due Loans | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total	9,723	15,524
Commercial Loans | Total Past Due Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total	882	4,587
Commercial Loans | Total Past Due Loans | Commercial construction
Financing Receivable, Past Due [Line Items]
Total	4,960	384
Commercial Loans | Total Past Due Loans | Business banking
Financing Receivable, Past Due [Line Items]
Total	9,717	6,358
Commercial Loans | 30-59 Days Past Due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total	0	8,424
Commercial Loans | 30-59 Days Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total	4	4,304
Commercial Loans | 30-59 Days Past Due | Commercial construction
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Loans | 30-59 Days Past Due | Business banking
Financing Receivable, Past Due [Line Items]
Total	3,525	1,583
Commercial Loans | 60-89 Days Past Due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total	3,403	0
Commercial Loans | 60-89 Days Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Loans | 60-89 Days Past Due | Commercial construction
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Loans | 60-89 Days Past Due | Business banking
Financing Receivable, Past Due [Line Items]
Total	2,045	285
Consumer Loans | Consumer real estate
Financing Receivable, Past Due [Line Items]
Total	1,731,778	1,421,953
Nonaccrual	6,312	6,526	7,294
Consumer Loans | Other consumer
Financing Receivable, Past Due [Line Items]
Total	114,897	124,878
Nonaccrual	330	269	$ 158
Consumer Loans | Current | Consumer real estate
Financing Receivable, Past Due [Line Items]
Total	1,719,751	1,409,907
Consumer Loans | Current | Other consumer
Financing Receivable, Past Due [Line Items]
Total	114,138	124,384
Consumer Loans | Total Past Due Loans | Consumer real estate
Financing Receivable, Past Due [Line Items]
Total	12,027	12,046
Consumer Loans | Total Past Due Loans | Other consumer
Financing Receivable, Past Due [Line Items]
Total	759	494
Consumer Loans | 30-59 Days Past Due | Consumer real estate
Financing Receivable, Past Due [Line Items]
Total	3,352	3,617
Consumer Loans | 30-59 Days Past Due | Other consumer
Financing Receivable, Past Due [Line Items]
Total	366	165
Consumer Loans | 60-89 Days Past Due | Consumer real estate
Financing Receivable, Past Due [Line Items]
Total	2,363	1,903
Consumer Loans | 60-89 Days Past Due | Other consumer
Financing Receivable, Past Due [Line Items]
Total	$ 63	$ 60