v3.25.2
Investment securities - Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Detail) - USD ($)
$ in Thousands
Jun. 30, 2025
Dec. 31, 2024
Debt securities available for sale:    
Due in one year or less $ 2,895,000  
Due after one year through five years 4,912,000  
Due after five years through ten years 0  
Due after ten years 0  
Total available for sale (amortized cost) 7,807,000  
Mortgage-backed securities 13,651,000  
Investment securities available for sale, amortized cost 21,458,000 $ 19,054,000
Debt securities held to maturity:    
Due in one year or less 82,000  
Due after one year through five years 641,000  
Due after five years through ten years 1,399,000  
Due after ten years 548,000  
Total available for held to maturity (amortized cost) 2,670,000  
Mortgage-backed securities 10,354,000  
Amortized cost for held to maturity 13,024,000 14,195,000
Debt securities available for sale:    
Due in one year or less 2,900,000  
Due after one year through five years 4,940,000  
Due after five years through ten years 0  
Due after ten years 0  
Total available for sale (fair value) 7,840,000  
Mortgage-backed securities 13,700,000  
Investment securities available for sale, estimated fair value 21,540,000 18,849,000
Debt securities held to maturity:    
Due in one year or less 82,000  
Due after one year through five years 631,000  
Due after five years through ten years 1,360,000  
Due after ten years 487,000  
Total available for held to maturity (fair value) 2,560,000  
Mortgage-backed securities 9,513,000  
Estimated fair value for held to maturity $ 12,073,000 $ 12,955,000