Loans and Leases - Major Classes of Loans And Leases (Detail) - USD ($) $ in Thousands |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Commercial, financial and agricultural: | ||
| Total commercial, financial & agricultural | $ 14,985,145 | $ 14,274,274 |
| Residential real estate | 6,257,512 | 6,098,262 |
| Construction & land development | 3,398,426 | 3,570,902 |
| Consumer: | ||
| Bankcard | 9,215 | 9,686 |
| Other consumer | 823,184 | 767,496 |
| Less: Unearned income | (13,224) | (11,498) |
| Loans and leases, net of unearned income | 25,460,258 | 24,709,122 |
| Owner-Occupied Commercial Real Estate [Member] | ||
| Commercial, financial and agricultural: | ||
| Total commercial, financial & agricultural | 2,177,293 | 2,145,921 |
| Nonowner-Occupied Commercial Real Estate [Member] | ||
| Commercial, financial and agricultural: | ||
| Total commercial, financial & agricultural | 9,033,200 | 8,343,520 |
| Other Commercial Loans And Leases [Member] | ||
| Commercial, financial and agricultural: | ||
| Total commercial, financial & agricultural | $ 3,774,652 | $ 3,784,833 |