Annual report [Section 13 and 15(d), not S-K Item 405]

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)

v3.25.0.1
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
Dec. 31, 2024
USD ($)
Security
Dec. 31, 2023
USD ($)
Security
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (1,447) $ (106)
Available-for-Sale Within One Year, Estimated Fair Value $ 144,646 $ 30,422
Available-for-Sale Within One Year, Number of Securities | Security 42 14
Available-for-Sale More than One Year, Gross Unrealized Loss $ (98,219) $ (102,077)
Available-for-Sale More than One Year, Estimated Fair Value $ 630,005 $ 747,988
Available-for-Sale More than One Year, Number of Securities | Security 195 213
Available-for-Sale, Gross Unrealized Loss $ (99,666) $ (102,183)
Available-for-Sale, Estimated Fair Value $ 774,651 $ 778,410
Available-for-Sale, Number of Securities | Security 237 227
U.S. Treasury securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (61) $ (57)
Available-for-Sale Within One Year, Estimated Fair Value $ 13,603 $ 21,024
Available-for-Sale Within One Year, Number of Securities | Security 6 7
Available-for-Sale More than One Year, Gross Unrealized Loss $ (460) $ (983)
Available-for-Sale More than One Year, Estimated Fair Value $ 9,771 $ 32,449
Available-for-Sale More than One Year, Number of Securities | Security 3 11
Available-for-Sale, Gross Unrealized Loss $ (521) $ (1,040)
Available-for-Sale, Estimated Fair Value $ 23,374 $ 53,473
Available-for-Sale, Number of Securities | Security 9 18
Mortgage-backed securities - residential    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (271) $ (11)
Available-for-Sale Within One Year, Estimated Fair Value $ 23,276 $ 2,324
Available-for-Sale Within One Year, Number of Securities | Security 10 5
Available-for-Sale More than One Year, Gross Unrealized Loss $ (61,372) $ (62,686)
Available-for-Sale More than One Year, Estimated Fair Value $ 351,793 $ 411,417
Available-for-Sale More than One Year, Number of Securities | Security 114 118
Available-for-Sale, Gross Unrealized Loss $ (61,643) $ (62,697)
Available-for-Sale, Estimated Fair Value $ 375,069 $ 413,741
Available-for-Sale, Number of Securities | Security 124 123
Mortgage-backed securities - commercial    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (447)  
Available-for-Sale Within One Year, Estimated Fair Value $ 19,092  
Available-for-Sale Within One Year, Number of Securities | Security 5  
Available-for-Sale More than One Year, Gross Unrealized Loss $ (12,608) $ (11,982)
Available-for-Sale More than One Year, Estimated Fair Value $ 41,817 $ 47,991
Available-for-Sale More than One Year, Number of Securities | Security 14 15
Available-for-Sale, Gross Unrealized Loss $ (13,055) $ (11,982)
Available-for-Sale, Estimated Fair Value $ 60,909 $ 47,991
Available-for-Sale, Number of Securities | Security 19 15
Collateralized mortgage obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (645) $ (38)
Available-for-Sale Within One Year, Estimated Fair Value $ 76,963 $ 7,074
Available-for-Sale Within One Year, Number of Securities | Security 18 2
Available-for-Sale More than One Year, Gross Unrealized Loss $ (8,756) $ (9,611)
Available-for-Sale More than One Year, Estimated Fair Value $ 54,020 $ 63,610
Available-for-Sale More than One Year, Number of Securities | Security 24 24
Available-for-Sale, Gross Unrealized Loss $ (9,401) $ (9,649)
Available-for-Sale, Estimated Fair Value $ 130,983 $ 70,684
Available-for-Sale, Number of Securities | Security 42 26
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 $ (3,946) $ (7,590)
Available-for-Sale More than One Year, Estimated Fair Value $ 107,595 $ 124,625
Available-for-Sale More than One Year, Number of Securities | Security 21 26
Available-for-Sale, Gross Unrealized Loss $ (3,969) $ (7,590)
Available-for-Sale, Estimated Fair Value $ 119,307 $ 124,625
Available-for-Sale, Number of Securities | Security 24 26
Total U.S. government agency and sponsored agency obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (1,386) $ (49)
Available-for-Sale Within One Year, Estimated Fair Value $ 131,043 $ 9,398
Available-for-Sale Within One Year, Number of Securities | Security 36 7
Available-for-Sale More than One Year, Gross Unrealized Loss $ (86,682) $ (91,869)
Available-for-Sale More than One Year, Estimated Fair Value $ 555,225 $ 647,643
Available-for-Sale More than One Year, Number of Securities | Security 173 183
Available-for-Sale, Gross Unrealized Loss $ (88,068) $ (91,918)
Available-for-Sale, Estimated Fair Value $ 686,268 $ 657,041
Available-for-Sale, Number of Securities | Security 209 190
Municipal bonds-tax exempt    
Summary of Investment Holdings [Line Items]    
Available-for-Sale More than One Year, Gross Unrealized Loss $ (11,077) $ (9,225)
Available-for-Sale More than One Year, Estimated Fair Value $ 65,009 $ 67,896
Available-for-Sale More than One Year, Number of Securities | Security 19 19
Available-for-Sale, Gross Unrealized Loss $ (11,077) $ (9,225)
Available-for-Sale, Estimated Fair Value $ 65,009 $ 67,896
Available-for-Sale, Number of Securities | Security 19 19