Annual report pursuant to Section 13 and 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)

v3.24.0.1
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, 2023
USD ($)
Security
Dec. 31, 2022
USD ($)
Security
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (106) $ (4,324)
Available-for-Sale Within One Year, Estimated Fair Value $ 30,422 $ 129,210
Available-for-Sale Within One Year, Number of Securities | Security 14 49
Available-for-Sale More than One Year, Gross Unrealized Loss $ (102,077) $ (120,697)
Available-for-Sale More than One Year, Estimated Fair Value $ 747,988 $ 719,787
Available-for-Sale More than One Year, Number of Securities | Security 213 184
Available-for-Sale, Gross Unrealized Loss $ (102,183) $ (125,021)
Available-for-Sale, Estimated Fair Value $ 778,410 $ 848,997
Available-for-Sale, Number of Securities | Security 227 233
U.S. Treasury securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (57) $ (414)
Available-for-Sale Within One Year, Estimated Fair Value $ 21,024 $ 33,812
Available-for-Sale Within One Year, Number of Securities | Security 7 14
Available-for-Sale More than One Year, Gross Unrealized Loss $ (983) $ (1,250)
Available-for-Sale More than One Year, Estimated Fair Value $ 32,449 $ 14,215
Available-for-Sale More than One Year, Number of Securities | Security 11 4
Available-for-Sale, Gross Unrealized Loss $ (1,040) $ (1,664)
Available-for-Sale, Estimated Fair Value $ 53,473 $ 48,027
Available-for-Sale, Number of Securities | Security 18 18
Mortgage-backed securities - residential    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (11) $ (1,712)
Available-for-Sale Within One Year, Estimated Fair Value $ 2,324 $ 36,009
Available-for-Sale Within One Year, Number of Securities | Security 5 18
Available-for-Sale More than One Year, Gross Unrealized Loss $ (62,686) $ (73,789)
Available-for-Sale More than One Year, Estimated Fair Value $ 411,417 $ 424,302
Available-for-Sale More than One Year, Number of Securities | Security 118 105
Available-for-Sale, Gross Unrealized Loss $ (62,697) $ (75,501)
Available-for-Sale, Estimated Fair Value $ 413,741 $ 460,311
Available-for-Sale, Number of Securities | Security 123 123
Mortgage-backed securities - commercial    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss   $ (84)
Available-for-Sale Within One Year, Estimated Fair Value   $ 4,069
Available-for-Sale Within One Year, Number of Securities | Security   1
Available-for-Sale More than One Year, Gross Unrealized Loss $ (11,982) $ (10,423)
Available-for-Sale More than One Year, Estimated Fair Value $ 47,991 $ 47,221
Available-for-Sale More than One Year, Number of Securities | Security 15 14
Available-for-Sale, Gross Unrealized Loss $ (11,982) $ (10,507)
Available-for-Sale, Estimated Fair Value $ 47,991 $ 51,290
Available-for-Sale, Number of Securities | Security 15 15
Collateralized mortgage obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (38) $ (1,011)
Available-for-Sale Within One Year, Estimated Fair Value $ 7,074 $ 23,606
Available-for-Sale Within One Year, Number of Securities | Security 2 8
Available-for-Sale More than One Year, Gross Unrealized Loss $ (9,611) $ (11,740)
Available-for-Sale More than One Year, Estimated Fair Value $ 63,610 $ 61,879
Available-for-Sale More than One Year, Number of Securities | Security 24 20
Available-for-Sale, Gross Unrealized Loss $ (9,649) $ (12,751)
Available-for-Sale, Estimated Fair Value $ 70,684 $ 85,485
Available-for-Sale, Number of Securities | Security 26 28
Debt securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss   $ (1,103)
Available-for-Sale Within One Year, Estimated Fair Value   $ 31,714
Available-for-Sale Within One Year, Number of Securities | Security   8
Available-for-Sale More than One Year, Gross Unrealized Loss $ (7,590) $ (10,736)
Available-for-Sale More than One Year, Estimated Fair Value $ 124,625 $ 106,785
Available-for-Sale More than One Year, Number of Securities | Security 26 22
Available-for-Sale, Gross Unrealized Loss $ (7,590) $ (11,839)
Available-for-Sale, Estimated Fair Value $ 124,625 $ 138,499
Available-for-Sale, Number of Securities | Security 26 30
Total U.S. government agency and sponsored agency obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (49) $ (3,910)
Available-for-Sale Within One Year, Estimated Fair Value $ 9,398 $ 95,398
Available-for-Sale Within One Year, Number of Securities | Security 7 35
Available-for-Sale More than One Year, Gross Unrealized Loss $ (91,869) $ (106,688)
Available-for-Sale More than One Year, Estimated Fair Value $ 647,643 $ 640,187
Available-for-Sale More than One Year, Number of Securities | Security 183 161
Available-for-Sale, Gross Unrealized Loss $ (91,918) $ (110,598)
Available-for-Sale, Estimated Fair Value $ 657,041 $ 735,585
Available-for-Sale, Number of Securities | Security 190 196
Municipal bonds-tax exempt    
Summary of Investment Holdings [Line Items]    
Available-for-Sale More than One Year, Gross Unrealized Loss $ (9,225) $ (12,759)
Available-for-Sale More than One Year, Estimated Fair Value $ 67,896 $ 65,385
Available-for-Sale More than One Year, Number of Securities | Security 19 19
Available-for-Sale, Gross Unrealized Loss $ (9,225) $ (12,759)
Available-for-Sale, Estimated Fair Value $ 67,896 $ 65,385
Available-for-Sale, Number of Securities | Security 19 19