Quarterly report [Sections 13 or 15(d)]

Securities - Summary of Investment Securities Available for Sale (Detail)

v3.26.3
Securities - Summary of Investment Securities Available for Sale (Detail) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost $ 957,828 $ 941,760
Gross Unrealized Gain 54 3,108
Gross Unrealized Loss (88,383) (64,244)
Estimated Fair Value 869,499 880,624
U.S. Treasury securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 226,273 128,569
Gross Unrealized Gain   298
Gross Unrealized Loss (1,222) (157)
Estimated Fair Value 225,051 128,710
Mortgage-backed securities - residential    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 384,273 411,223
Gross Unrealized Gain 8 926
Gross Unrealized Loss (50,734) (38,741)
Estimated Fair Value 333,547 373,408
Mortgage-backed securities - commercial    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 78,566 71,751
Gross Unrealized Gain   116
Gross Unrealized Loss (14,752) (11,295)
Estimated Fair Value 63,814 60,572
Collateralized mortgage obligations    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 159,907 188,120
Gross Unrealized Gain 46 1,768
Gross Unrealized Loss (8,894) (5,933)
Estimated Fair Value 151,059 183,955
Other U.S. government agency obligations    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 34,567 67,059
Gross Unrealized Loss (484) (1,105)
Estimated Fair Value 34,083 65,954
Total U.S. government agency and sponsored agency obligations    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 657,313 738,153
Gross Unrealized Gain 54 2,810
Gross Unrealized Loss (74,864) (57,074)
Estimated Fair Value 582,503 683,889
Municipal bonds-tax exempt    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 74,242 75,038
Gross Unrealized Loss (12,297) (7,013)
Estimated Fair Value $ 61,945 $ 68,025