v3.25.2
Investment Securities - Summary of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Detail) - USD ($)
$ in Thousands
Jun. 30, 2025
Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]    
Due in one year or less, Amortized Cost, Available-for-sale $ 40,593  
Due in one year or less, Fair Value, Available-for-sale 40,552  
Due after one year through five years, Amortized Cost, Available-for-sale 258,065  
Due after one year through five years, Fair Value, Available-for-sale 243,018  
Due after five years through ten years, Amortized Cost, Available-for-sale 1,719,933  
Due after five years through ten years, Fair Value, Available-for-sale 1,495,301  
Due after ten years, Amortized Cost, Available-for-sale 821,859  
Due after ten years, Fair Value, Available-for-sale 707,435  
Amortized Cost, Available-for-sale 2,840,450 $ 2,997,047
Total Available-for-sale Securities, Debt Maturities, Available-for-sale, Fair Value 2,486,306 $ 2,542,115
Due in one year or less, Amortized Cost, Held-to-maturity 17,109  
Due after one year through five years, Amortized Cost, Held-to-maturity 47,915  
Due after five years through ten years, Amortized Cost, Held-to-maturity 314,931  
Due after ten years, Amortized Cost, Held-to-maturity 1,947,275  
Total Held-to-maturity, Debt Maturities, Amortized Cost Basis 2,327,230  
Due in one year or less, Fair Value, Held-to-maturity 16,746  
Due after one year through five years, Fair Value, Held-to-maturity 46,837  
Due after five years through ten years, Fair Value, Held-to-maturity 280,154  
Due after ten years, Fair Value, Held-to-maturity 1,591,019  
Total, Held-to-maturity, Fair Value $ 1,934,756