Quarterly report pursuant to Section 13 or 15(d)

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

v3.23.3
Securities - Summary of Investment Securities Available for Sale (Detail) - USD ($)
$ in Thousands
Sep. 30, 2023
Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost $ 957,272 $ 978,796
Gross Unrealized Gain   63
Gross Unrealized Loss (140,030) (125,021)
Estimated Fair Value 817,242 853,838
U.S. Treasury securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 72,561 49,690
Gross Unrealized Loss (1,639) (1,664)
Estimated Fair Value 70,922 48,026
Mortgage-backed securities - residential    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 507,922 540,590
Gross Unrealized Gain   63
Gross Unrealized Loss (85,196) (75,501)
Estimated Fair Value 422,726 465,152
Mortgage-backed securities - commercial    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 60,407 61,799
Gross Unrealized Loss (14,441) (10,507)
Estimated Fair Value 45,966 51,292
Collateralized mortgage obligations    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 98,595 98,236
Gross Unrealized Loss (12,337) (12,751)
Estimated Fair Value 86,258 85,485
Debt securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 140,409 150,338
Gross Unrealized Loss (10,490) (11,839)
Estimated Fair Value 129,919 138,499
Total U.S. government agency and sponsored agency obligations    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 807,333 850,963
Gross Unrealized Gain   63
Gross Unrealized Loss (122,464) (110,598)
Estimated Fair Value 684,869 740,428
Municipal bonds-tax exempt    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 77,378 78,143
Gross Unrealized Loss (15,927) (12,759)
Estimated Fair Value $ 61,451 $ 65,384