Loans and Allowance for Credit Losses - Schedule of Shows the Age Analysis of Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Total	$ 14,109,919	$ 13,948,360
Total Past Due
Financing Receivable, Past Due [Line Items]
Total	49,230	57,130
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	28,477	30,936
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	7,337	9,370
90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	13,416	16,824
Current
Financing Receivable, Past Due [Line Items]
Total	14,060,689	13,891,230
Commercial and industrial | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	3,071,207	3,019,631
Commercial and industrial | Total Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	9	3,781
Commercial and industrial | 30-59 Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	3,316
Commercial and industrial | 60-89 Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial and industrial | 90 or More Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	9	465
Commercial and industrial | Current | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	3,071,198	3,015,850
Commercial real estate | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	5,437,398	5,453,847
Commercial real estate | Total Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial real estate | 30-59 Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial real estate | 60-89 Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial real estate | 90 or More Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial real estate | Current | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	5,437,398	5,453,847
Commercial construction | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	445,227	384,637
Commercial construction | Total Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial construction | 30-59 Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial construction | 60-89 Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial construction | 90 or More Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial construction | Current | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	445,227	384,637
Business banking | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	1,110,943	1,089,593
Business banking | Total Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	5,562	6,304
Business banking | 30-59 Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	3,499	3,455
Business banking | 60-89 Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	187	1,647
Business banking | 90 or More Days Past Due | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	1,876	1,202
Business banking | Current | Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	1,105,381	1,083,289
Residential real estate | Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total	2,577,765	2,582,465
Residential real estate | Total Past Due | Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total	27,522	28,768
Residential real estate | 30-59 Days Past Due | Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total	16,801	17,116
Residential real estate | 60-89 Days Past Due | Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total	5,574	4,888
Residential real estate | 90 or More Days Past Due | Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total	5,147	6,764
Residential real estate | Current | Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total	2,550,243	2,553,697
Consumer home equity | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	1,256,810	1,211,168
Consumer home equity | Total Past Due | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	15,528	17,321
Consumer home equity | 30-59 Days Past Due | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	7,880	6,517
Consumer home equity | 60-89 Days Past Due | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	1,392	2,600
Consumer home equity | 90 or More Days Past Due | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	6,256	8,204
Consumer home equity | Current | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	1,241,282	1,193,847
Other Consumer | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	210,569	207,019
Other Consumer | Total Past Due | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	609	956
Other Consumer | 30-59 Days Past Due | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	297	532
Other Consumer | 60-89 Days Past Due | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	184	235
Other Consumer | 90 or More Days Past Due | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	128	189
Other Consumer | Current | Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Total	$ 209,960	$ 206,063