v3.26.1
Loans and the Allowance for Credit Losses - Summary of Age Analysis of Loan Categories (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income $ 19,478,966 $ 19,226,432
90 Days or More Past Due and Accruing 21,783 37,783
Loans held for sale 57,318 87,454
Total loans, current 19,322,851 19,113,248
Total loans 19,536,284 19,313,886
Home Equity [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 1,191,809 1,129,394
90 Days or More Past Due and Accruing 2,030 2,882
Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 11,093,370 10,938,834
90 Days or More Past Due and Accruing 5,313 20,507
Residential Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 3,939,813 3,938,585
90 Days or More Past Due and Accruing 12,581 12,479
Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 304,111 355,726
90 Days or More Past Due and Accruing 709 1,138
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 1,505,492 1,783,637
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 9,587,878 9,155,197
90 Days or More Past Due and Accruing 5,313 20,507
Commercial and Industrial [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 2,949,863 2,863,893
90 Days or More Past Due and Accruing 1,150 777
Non-Accrual Loans [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 146,058 91,584
Current [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 19,265,533 19,025,794
Loans held for sale, current 57,318 87,454
Current [Member] | Home Equity [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 1,173,135 1,106,652
Current [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 10,981,162 10,845,474
Current [Member] | Residential Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 3,889,233 3,889,494
Current [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 298,240 345,927
Current [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 1,475,666 1,755,314
Current [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 9,505,496 9,090,160
Current [Member] | Commercial and Industrial [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 2,923,763 2,838,247
Current [Member] | Non-Accrual Loans [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 21,796 19,928
30-59 Days Past Due [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 39,647 45,847
30-59 Days Past Due [Member] | Home Equity [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 7,588 9,938
30-59 Days Past Due [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 24,780 26,997
30-59 Days Past Due [Member] | Residential Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 956 738
30-59 Days Past Due [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 3,967 6,119
30-59 Days Past Due [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 1,184 13,535
30-59 Days Past Due [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 23,596 13,462
30-59 Days Past Due [Member] | Commercial and Industrial [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 2,356 2,055
30-59 Days Past Due [Member] | Non-Accrual Loans [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 726 1,215
60-89 Days Past Due [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 30,775 48,523
60-89 Days Past Due [Member] | Home Equity [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 2,897 4,162
60-89 Days Past Due [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 7,996 21,592
60-89 Days Past Due [Member] | Residential Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 14,950 13,513
60-89 Days Past Due [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 1,422 1,822
60-89 Days Past Due [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 497 13,956
60-89 Days Past Due [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 7,499 7,636
60-89 Days Past Due [Member] | Commercial and Industrial [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 3,510 7,434
60-89 Days Past Due [Member] | Non-Accrual Loans [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 2,308 1,956
90 Days or More Past Due [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 143,011 106,268
90 Days or More Past Due [Member] | Home Equity [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 8,189 8,642
90 Days or More Past Due [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 79,432 44,771
90 Days or More Past Due [Member] | Residential Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 34,674 34,840
90 Days or More Past Due [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 482 1,858
90 Days or More Past Due [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 28,145 832
90 Days or More Past Due [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 51,287 43,939
90 Days or More Past Due [Member] | Commercial and Industrial [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 20,234 16,157
90 Days or More Past Due [Member] | Non-Accrual Loans [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 121,228 68,485
Total Past Due [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 213,433 200,638
Total Past Due [Member] | Home Equity [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 18,674 22,742
Total Past Due [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 112,208 93,360
Total Past Due [Member] | Residential Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 50,580 49,091
Total Past Due [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 5,871 9,799
Total Past Due [Member] | Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 29,826 28,323
Total Past Due [Member] | Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 82,382 65,037
Total Past Due [Member] | Commercial and Industrial [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income 26,100 25,646
Total Past Due [Member] | Non-Accrual Loans [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Portfolio loans, net of unearned income $ 124,262 $ 71,656