Quarterly report [Sections 13 or 15(d)]

Securities - Summary of Debt Securities Available for Sale in an Unrealized Loss Position for Which an Allowance for Credit Losses Has Not Been Recorded (Detail)

v3.25.2
Securities - Summary of Debt Securities Available for Sale in an Unrealized Loss Position for Which an Allowance for Credit Losses Has Not Been Recorded (Detail)
$ in Thousands
Jun. 30, 2025
USD ($)
Security
Dec. 31, 2024
USD ($)
Security
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (547) $ (1,447)
Available-for-Sale Within One Year, Estimated Fair Value $ 66,769 $ 144,646
Available-for-Sale Within One Year, Number of Securities | Security 20 42
Available-for-Sale More than One Year, Gross Unrealized Loss $ (78,707) $ (98,219)
Available-for-Sale More than One Year, Estimated Fair Value $ 572,890 $ 630,005
Available-for-Sale More than One Year, Number of Securities | Security 183 195
Available-for-Sale, Gross Unrealized Loss $ (79,254) $ (99,666)
Available-for-Sale, Estimated Fair Value $ 639,659 $ 774,651
Available-for-Sale, Number of Securities | Security 203 237
U.S. Treasury securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (28) $ (61)
Available-for-Sale Within One Year, Estimated Fair Value $ 27,020 $ 13,603
Available-for-Sale Within One Year, Number of Securities | Security 7 6
Available-for-Sale More than One Year, Gross Unrealized Loss $ (295) $ (460)
Available-for-Sale More than One Year, Estimated Fair Value $ 8,193 $ 9,771
Available-for-Sale More than One Year, Number of Securities | Security 2 3
Available-for-Sale, Gross Unrealized Loss $ (323) $ (521)
Available-for-Sale, Estimated Fair Value $ 35,213 $ 23,374
Available-for-Sale, Number of Securities | Security 9 9
Mortgage-backed securities - residential    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (179) $ (271)
Available-for-Sale Within One Year, Estimated Fair Value $ 19,577 $ 23,276
Available-for-Sale Within One Year, Number of Securities | Security 7 10
Available-for-Sale More than One Year, Gross Unrealized Loss $ (46,926) $ (61,372)
Available-for-Sale More than One Year, Estimated Fair Value $ 338,997 $ 351,793
Available-for-Sale More than One Year, Number of Securities | Security 113 114
Available-for-Sale, Gross Unrealized Loss $ (47,105) $ (61,643)
Available-for-Sale, Estimated Fair Value $ 358,574 $ 375,069
Available-for-Sale, Number of Securities | Security 120 124
Mortgage-backed securities - commercial    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (309) $ (447)
Available-for-Sale Within One Year, Estimated Fair Value $ 14,631 $ 19,092
Available-for-Sale Within One Year, Number of Securities | Security 4 5
Available-for-Sale More than One Year, Gross Unrealized Loss $ (11,721) $ (12,608)
Available-for-Sale More than One Year, Estimated Fair Value $ 40,470 $ 41,817
Available-for-Sale More than One Year, Number of Securities | Security 12 14
Available-for-Sale, Gross Unrealized Loss $ (12,030) $ (13,055)
Available-for-Sale, Estimated Fair Value $ 55,101 $ 60,909
Available-for-Sale, Number of Securities | Security 16 19
Collateralized mortgage obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (31) $ (645)
Available-for-Sale Within One Year, Estimated Fair Value $ 5,541 $ 76,963
Available-for-Sale Within One Year, Number of Securities | Security 2 18
Available-for-Sale More than One Year, Gross Unrealized Loss $ (7,145) $ (8,756)
Available-for-Sale More than One Year, Estimated Fair Value $ 50,234 $ 54,020
Available-for-Sale More than One Year, Number of Securities | Security 23 24
Available-for-Sale, Gross Unrealized Loss $ (7,176) $ (9,401)
Available-for-Sale, Estimated Fair Value $ 55,775 $ 130,983
Available-for-Sale, Number of Securities | Security 25 42
Debt securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss   $ (23)
Available-for-Sale Within One Year, Estimated Fair Value   $ 11,712
Available-for-Sale Within One Year, Number of Securities | Security   3
Available-for-Sale More than One Year, Gross Unrealized Loss $ (2,133) $ (3,946)
Available-for-Sale More than One Year, Estimated Fair Value $ 69,919 $ 107,595
Available-for-Sale More than One Year, Number of Securities | Security 14 21
Available-for-Sale, Gross Unrealized Loss $ (2,133) $ (3,969)
Available-for-Sale, Estimated Fair Value $ 69,919 $ 119,307
Available-for-Sale, Number of Securities | Security 14 24
Total U.S. government agency and sponsored agency obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (519) $ (1,386)
Available-for-Sale Within One Year, Estimated Fair Value $ 39,749 $ 131,043
Available-for-Sale Within One Year, Number of Securities | Security 13 36
Available-for-Sale More than One Year, Gross Unrealized Loss $ (67,925) $ (86,682)
Available-for-Sale More than One Year, Estimated Fair Value $ 499,620 $ 555,225
Available-for-Sale More than One Year, Number of Securities | Security 162 173
Available-for-Sale, Gross Unrealized Loss $ (68,444) $ (88,068)
Available-for-Sale, Estimated Fair Value $ 539,369 $ 686,268
Available-for-Sale, Number of Securities | Security 175 209
Municipal bonds-tax exempt    
Summary of Investment Holdings [Line Items]    
Available-for-Sale More than One Year, Gross Unrealized Loss $ (10,487) $ (11,077)
Available-for-Sale More than One Year, Estimated Fair Value $ 65,077 $ 65,009
Available-for-Sale More than One Year, Number of Securities | Security 19 19
Available-for-Sale, Gross Unrealized Loss $ (10,487) $ (11,077)
Available-for-Sale, Estimated Fair Value $ 65,077 $ 65,009
Available-for-Sale, Number of Securities | Security 19 19