Quarterly report pursuant to Section 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)

v3.23.2
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, 2023
USD ($)
Security
Dec. 31, 2022
USD ($)
Security
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (2,689) $ (4,324)
Available-for-Sale Within One Year, Estimated Fair Value $ 114,153 $ 129,210
Available-for-Sale Within One Year, Number of Securities | Security 42 49
Available-for-Sale More than One Year, Gross Unrealized Loss $ (116,531) $ (120,697)
Available-for-Sale More than One Year, Estimated Fair Value $ 715,446 $ 719,787
Available-for-Sale More than One Year, Number of Securities | Security 194 184
Available-for-Sale, Gross Unrealized Loss $ (119,220) $ (125,021)
Available-for-Sale, Estimated Fair Value $ 829,599 $ 848,997
Available-for-Sale, Number of Securities | Security 236 233
U.S. Treasury securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (374) $ (414)
Available-for-Sale Within One Year, Estimated Fair Value $ 37,090 $ 33,812
Available-for-Sale Within One Year, Number of Securities | Security 15 14
Available-for-Sale More than One Year, Gross Unrealized Loss $ (1,321) $ (1,250)
Available-for-Sale More than One Year, Estimated Fair Value $ 19,394 $ 14,215
Available-for-Sale More than One Year, Number of Securities | Security 6 4
Available-for-Sale, Gross Unrealized Loss $ (1,695) $ (1,664)
Available-for-Sale, Estimated Fair Value $ 56,484 $ 48,027
Available-for-Sale, Number of Securities | Security 21 18
Mortgage-backed securities - residential    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (1,448) $ (1,712)
Available-for-Sale Within One Year, Estimated Fair Value $ 34,738 $ 36,009
Available-for-Sale Within One Year, Number of Securities | Security 16 18
Available-for-Sale More than One Year, Gross Unrealized Loss $ (70,432) $ (73,789)
Available-for-Sale More than One Year, Estimated Fair Value $ 404,808 $ 424,302
Available-for-Sale More than One Year, Number of Securities | Security 108 105
Available-for-Sale, Gross Unrealized Loss $ (71,880) $ (75,501)
Available-for-Sale, Estimated Fair Value $ 439,546 $ 460,311
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 $ (88) $ (84)
Available-for-Sale Within One Year, Estimated Fair Value $ 4,077 $ 4,069
Available-for-Sale Within One Year, Number of Securities | Security 1 1
Available-for-Sale More than One Year, Gross Unrealized Loss $ (11,926) $ (10,423)
Available-for-Sale More than One Year, Estimated Fair Value $ 44,701 $ 47,221
Available-for-Sale More than One Year, Number of Securities | Security 14 14
Available-for-Sale, Gross Unrealized Loss $ (12,014) $ (10,507)
Available-for-Sale, Estimated Fair Value $ 48,778 $ 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 $ (633) $ (1,011)
Available-for-Sale Within One Year, Estimated Fair Value $ 24,462 $ 23,606
Available-for-Sale Within One Year, Number of Securities | Security 6 8
Available-for-Sale More than One Year, Gross Unrealized Loss $ (10,693) $ (11,740)
Available-for-Sale More than One Year, Estimated Fair Value $ 59,614 $ 61,879
Available-for-Sale More than One Year, Number of Securities | Security 22 20
Available-for-Sale, Gross Unrealized Loss $ (11,326) $ (12,751)
Available-for-Sale, Estimated Fair Value $ 84,076 $ 85,485
Available-for-Sale, Number of Securities | Security 28 28
Debt securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (146) $ (1,103)
Available-for-Sale Within One Year, Estimated Fair Value $ 13,786 $ 31,714
Available-for-Sale Within One Year, Number of Securities | Security 4 8
Available-for-Sale More than One Year, Gross Unrealized Loss $ (10,864) $ (10,736)
Available-for-Sale More than One Year, Estimated Fair Value $ 120,590 $ 106,785
Available-for-Sale More than One Year, Number of Securities | Security 25 22
Available-for-Sale, Gross Unrealized Loss $ (11,010) $ (11,839)
Available-for-Sale, Estimated Fair Value $ 134,376 $ 138,499
Available-for-Sale, Number of Securities | Security 29 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 $ (2,315) $ (3,910)
Available-for-Sale Within One Year, Estimated Fair Value $ 77,063 $ 95,398
Available-for-Sale Within One Year, Number of Securities | Security 27 35
Available-for-Sale More than One Year, Gross Unrealized Loss $ (103,915) $ (106,688)
Available-for-Sale More than One Year, Estimated Fair Value $ 629,713 $ 640,187
Available-for-Sale More than One Year, Number of Securities | Security 169 161
Available-for-Sale, Gross Unrealized Loss $ (106,230) $ (110,598)
Available-for-Sale, Estimated Fair Value $ 706,776 $ 735,585
Available-for-Sale, Number of Securities | Security 196 196
Municipal bonds-tax exempt    
Summary of Investment Holdings [Line Items]    
Available-for-Sale More than One Year, Gross Unrealized Loss $ (11,295) $ (12,759)
Available-for-Sale More than One Year, Estimated Fair Value $ 66,339 $ 65,385
Available-for-Sale More than One Year, Number of Securities | Security 19 19
Available-for-Sale, Gross Unrealized Loss $ (11,295) $ (12,759)
Available-for-Sale, Estimated Fair Value $ 66,339 $ 65,385
Available-for-Sale, Number of Securities | Security 19 19