v3.26.1
Loans and Allowance for Credit Losses - Additional Information (Detail) - USD ($)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Non Accrual Status Of Loans After Number Of Days Past Due     90 days    
Default Status Of TDRs After Number Of Days Past Due     90 days    
Charge-offs $ 12,960,000 $ 4,426,000 $ 22,397,000 $ 12,436,000 $ 38,366,000
Unfunded commitments related to nonperforming loans 3,200,000   3,200,000   200,000
Off balance sheet reserve to nonperforming loans 0   0   0
Total gains or losses included in earnings     $ 0 0  
Forecasted Value, National Unemployment, Percent     4.23%    
Financing Receivable, before Allowance for Credit Loss 9,467,229,000   $ 9,467,229,000   9,508,039,000
Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery     19,600,000 5,900,000  
Post- Modification Outstanding Recorded Investment 19,594,000 32,357,000 32,434,000 36,138,000  
Small Business Administration Guarantee          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 23,300,000   23,300,000   31,500,000
Net Deferred Fees          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Unearned Deferred (Fees) Costs on Loans 24,400,000   24,400,000   21,200,000
Unearned Premiums and Discounts          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Unearned Deferred (Fees) Costs on Loans (17,600,000)   (17,600,000)   (20,200,000)
Financial Asset, 30 to 59 Days Past Due [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 26,974,000   26,974,000   22,032,000
Financial Asset, Not Past Due          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 9,339,139,000   9,339,139,000   9,379,203,000
Non Accrual Loans [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 81,640,000   $ 81,640,000   91,756,000
Weighted average [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Forecasted Value, National Unemployment, Percent     5.13%    
Maximum [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Forecasted Value, National Unemployment, Percent     5.46%    
Time and Demand Loans          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs     $ 8,060,000   16,182,000
Financing Receivable, before Allowance for Credit Loss 1,151,708,000   1,151,708,000   1,226,054,000
Multifamily          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs     0   766,000
Financing Receivable, before Allowance for Credit Loss 636,826,000   636,826,000   594,790,000
Nonowner Occupied Commercial Real Estate          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs     3,568,000   4,770,000
Financing Receivable, before Allowance for Credit Loss 1,690,230,000   1,690,230,000   1,834,016,000
Commercial, financial, agricultural and other [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs 8,264,000 1,403,000 12,278,000 5,422,000  
Financing Receivable, before Allowance for Credit Loss 2,071,387,000   2,071,387,000   2,044,989,000
Post- Modification Outstanding Recorded Investment 988,000 32,192,000 988,000 32,192,000  
Commercial, financial, agricultural and other [Member] | Financial Asset, 30 to 59 Days Past Due [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 4,085,000   4,085,000   5,127,000
Commercial, financial, agricultural and other [Member] | Financial Asset, Not Past Due          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 2,014,570,000   2,014,570,000   1,992,432,000
Commercial, financial, agricultural and other [Member] | Non Accrual Loans [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 40,682,000   40,682,000   46,618,000
Commercial, financial, agricultural and other [Member] | Time and Demand Loans          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs 6,143,000 363,000 8,060,000 3,339,000  
Financing Receivable, before Allowance for Credit Loss 1,151,708,000   1,151,708,000   1,226,054,000
Post- Modification Outstanding Recorded Investment 988,000 31,880,000 988,000    
Commercial, financial, agricultural and other [Member] | Time and Demand Loans | Financial Asset, 30 to 59 Days Past Due [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 1,425,000   1,425,000   2,666,000
Commercial, financial, agricultural and other [Member] | Time and Demand Loans | Financial Asset, Not Past Due          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 1,101,440,000   1,101,440,000   1,177,868,000
Commercial, financial, agricultural and other [Member] | Time and Demand Loans | Non Accrual Loans [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 38,004,000   38,004,000   45,288,000
Commercial Real Estate [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs 2,212,000 624,000 4,520,000 2,088,000  
Financing Receivable, before Allowance for Credit Loss 3,083,774,000   3,083,774,000   3,182,109,000
Post- Modification Outstanding Recorded Investment 18,523,000   31,363,000 3,201,000  
Commercial Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 7,849,000   7,849,000   1,975,000
Commercial Real Estate [Member] | Financial Asset, Not Past Due          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 3,048,914,000   3,048,914,000   3,139,452,000
Commercial Real Estate [Member] | Non Accrual Loans [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 25,622,000   25,622,000   30,612,000
Commercial Real Estate [Member] | Multifamily          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs 0 0 0 0  
Financing Receivable, before Allowance for Credit Loss 636,826,000   636,826,000   594,790,000
Commercial Real Estate [Member] | Multifamily | Financial Asset, 30 to 59 Days Past Due [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 0   0   417,000
Commercial Real Estate [Member] | Multifamily | Financial Asset, Not Past Due          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 625,980,000   625,980,000   594,363,000
Commercial Real Estate [Member] | Multifamily | Non Accrual Loans [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 10,846,000   10,846,000   10,000
Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs 1,552,000 1,000 3,568,000 875,000  
Financing Receivable, before Allowance for Credit Loss 1,690,230,000   1,690,230,000   1,834,016,000
Post- Modification Outstanding Recorded Investment 7,687,000   20,527,000 3,201,000  
Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate | Financial Asset, 30 to 59 Days Past Due [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 1,163,000   1,163,000   534,000
Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate | Financial Asset, Not Past Due          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 1,682,678,000   1,682,678,000   1,809,256,000
Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate | Non Accrual Loans [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 6,389,000   6,389,000   14,156,000
Loans to individuals [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Charge-offs 2,170,000 $ 2,281,000 4,814,000 4,700,000  
Financing Receivable, before Allowance for Credit Loss 1,457,236,000   1,457,236,000   1,457,870,000
Loans to individuals [Member] | Financial Asset, 30 to 59 Days Past Due [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 6,276,000   6,276,000   6,733,000
Loans to individuals [Member] | Financial Asset, Not Past Due          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 1,449,257,000   1,449,257,000   1,449,390,000
Loans to individuals [Member] | Non Accrual Loans [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Financing Receivable, before Allowance for Credit Loss 7,000   $ 7,000   32,000
Loans to individuals [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Non Accrual Status Of Loans After Number Of Days Past Due     150 days    
Nonaccrual Commercial Loans [Member]          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Loans Held for sale, Amount $ 0   $ 0   $ 0
Loans and Leases Receivable, Gain (Loss) on Sales, Net     $ 0 $ 0