v3.26.1
Loans and the Allowance for Credit Losses - Summary of Aging Analysis of Portfolio Loans Restructured (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan $ 19,478,966 $ 19,226,432  
Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 97,426   $ 125,381
Home Equity [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 1,191,809 1,129,394  
Home Equity [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 1,280   1,744
Commercial and Industrial [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 2,949,863 2,863,893  
Commercial and Industrial [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 10,122   13,062
Commercial Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 11,093,370 10,938,834  
Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 1,505,492 1,783,637  
Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     25,050
Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 9,587,878 9,155,197  
Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 81,056   79,509
Residential Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 3,939,813 3,938,585  
Residential Real Estate [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 4,511   5,351
Consumer [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 304,111 355,726  
Consumer [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 457   665
30-59 Days Past Due [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 39,647 45,847  
30-59 Days Past Due [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 129   328
30-59 Days Past Due [Member] | Home Equity [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 7,588 9,938  
30-59 Days Past Due [Member] | Home Equity [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 25   297
30-59 Days Past Due [Member] | Commercial and Industrial [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 2,356 2,055  
30-59 Days Past Due [Member] | Commercial and Industrial [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 75    
30-59 Days Past Due [Member] | Commercial Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 24,780 26,997  
30-59 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 1,184 13,535  
30-59 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 23,596 13,462  
30-59 Days Past Due [Member] | Residential Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 956 738  
30-59 Days Past Due [Member] | Consumer [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 3,967 6,119  
30-59 Days Past Due [Member] | Consumer [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 29   31
60-89 Days Past Due [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 30,775 48,523  
60-89 Days Past Due [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 66   3,194
60-89 Days Past Due [Member] | Home Equity [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 2,897 4,162  
60-89 Days Past Due [Member] | Home Equity [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     132
60-89 Days Past Due [Member] | Commercial and Industrial [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 3,510 7,434  
60-89 Days Past Due [Member] | Commercial and Industrial [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     489
60-89 Days Past Due [Member] | Commercial Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 7,996 21,592  
60-89 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 497 13,956  
60-89 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 7,499 7,636  
60-89 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     1,446
60-89 Days Past Due [Member] | Residential Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 14,950 13,513  
60-89 Days Past Due [Member] | Residential Real Estate [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 66    
60-89 Days Past Due [Member] | Consumer [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 1,422 1,822  
60-89 Days Past Due [Member] | Consumer [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     88
90 Days or More Past Due [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 143,011 106,268  
90 Days or More Past Due [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 20,648   12,683
90 Days or More Past Due [Member] | Home Equity [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 8,189 8,642  
90 Days or More Past Due [Member] | Home Equity [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 415   343
90 Days or More Past Due [Member] | Commercial and Industrial [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 20,234 16,157  
90 Days or More Past Due [Member] | Commercial and Industrial [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 190   6,995
90 Days or More Past Due [Member] | Commercial Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 79,432 44,771  
90 Days or More Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 28,145 832  
90 Days or More Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     832
90 Days or More Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 51,287 43,939  
90 Days or More Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 19,324   3,468
90 Days or More Past Due [Member] | Residential Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 34,674 34,840  
90 Days or More Past Due [Member] | Residential Real Estate [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 719   953
90 Days or More Past Due [Member] | Consumer [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 482 1,858  
90 Days or More Past Due [Member] | Consumer [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     92
Total Past Due [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 213,433 200,638  
Total Past Due [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 20,843   16,205
Total Past Due [Member] | Home Equity [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 18,674 22,742  
Total Past Due [Member] | Home Equity [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 440   772
Total Past Due [Member] | Commercial and Industrial [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 26,100 25,646  
Total Past Due [Member] | Commercial and Industrial [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 265   7,484
Total Past Due [Member] | Commercial Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 112,208 93,360  
Total Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 29,826 28,323  
Total Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     832
Total Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 82,382 65,037  
Total Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 19,324   4,914
Total Past Due [Member] | Residential Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 50,580 49,091  
Total Past Due [Member] | Residential Real Estate [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 785   1,992
Total Past Due [Member] | Consumer [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 5,871 9,799  
Total Past Due [Member] | Consumer [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 29   211
Current [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 19,265,533 19,025,794  
Current [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 76,583   109,176
Current [Member] | Home Equity [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 1,173,135 1,106,652  
Current [Member] | Home Equity [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 840   972
Current [Member] | Commercial and Industrial [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 2,923,763 2,838,247  
Current [Member] | Commercial and Industrial [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 9,857   5,578
Current [Member] | Commercial Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 10,981,162 10,845,474  
Current [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 1,475,666 1,755,314  
Current [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan     24,218
Current [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 9,505,496 9,090,160  
Current [Member] | Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 61,732   74,595
Current [Member] | Residential Real Estate [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 3,889,233 3,889,494  
Current [Member] | Residential Real Estate [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 3,726   3,359
Current [Member] | Consumer [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan 298,240 $ 345,927  
Current [Member] | Consumer [Member] | Loan Modification [Member]      
Financing Receivable, Modified, Past Due [Line Items]      
Total modified loan $ 428   $ 454