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)

v3.21.2
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, 2021
USD ($)
Security
Dec. 31, 2020
USD ($)
Security
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (4,674) $ (406)
Available-for-Sale Within One Year, Estimated Fair Value $ 622,023 $ 178,681
Available-for-Sale Within One Year, Number of Securities | Security 114 32
Available-for-Sale More than One Year, Estimated Fair Value $ 14  
Available-for-Sale More than One Year, Number of Securities | Security 1  
Available-for-Sale, Gross Unrealized Loss $ (4,674) $ (406)
Available-for-Sale, Estimated Fair Value $ 622,037 $ 178,681
Available-for-Sale, Number of Securities | Security 115 32
Mortgage-backed securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (3,427) $ (188)
Available-for-Sale Within One Year, Estimated Fair Value $ 433,473 $ 76,023
Available-for-Sale Within One Year, Number of Securities | Security 72 10
Available-for-Sale, Gross Unrealized Loss $ (3,427) $ (188)
Available-for-Sale, Estimated Fair Value $ 433,473 $ 76,023
Available-for-Sale, Number of Securities | Security 72 10
Collateralized mortgage obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (380) $ (217)
Available-for-Sale Within One Year, Estimated Fair Value $ 54,099 $ 97,659
Available-for-Sale Within One Year, Number of Securities | Security 15 21
Available-for-Sale More than One Year, Estimated Fair Value $ 14  
Available-for-Sale More than One Year, Number of Securities | Security 1  
Available-for-Sale, Gross Unrealized Loss $ (380) $ (217)
Available-for-Sale, Estimated Fair Value $ 54,113 $ 97,659
Available-for-Sale, Number of Securities | Security 16 21
Debt securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (416) $ (1)
Available-for-Sale Within One Year, Estimated Fair Value $ 82,061 $ 4,999
Available-for-Sale Within One Year, Number of Securities | Security 14 1
Available-for-Sale, Gross Unrealized Loss $ (416) $ (1)
Available-for-Sale, Estimated Fair Value $ 82,061 $ 4,999
Available-for-Sale, Number of Securities | Security 14 1
Total U.S. government agency and sponsored agency obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (4,223) $ (406)
Available-for-Sale Within One Year, Estimated Fair Value $ 569,633 $ 178,681
Available-for-Sale Within One Year, Number of Securities | Security 101 32
Available-for-Sale More than One Year, Estimated Fair Value $ 14  
Available-for-Sale More than One Year, Number of Securities | Security 1  
Available-for-Sale, Gross Unrealized Loss $ (4,223) $ (406)
Available-for-Sale, Estimated Fair Value $ 569,647 $ 178,681
Available-for-Sale, Number of Securities | Security 102 32
Municipal bonds-tax exempt    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (451)  
Available-for-Sale Within One Year, Estimated Fair Value $ 52,390  
Available-for-Sale Within One Year, Number of Securities | Security 13  
Available-for-Sale, Gross Unrealized Loss $ (451)  
Available-for-Sale, Estimated Fair Value $ 52,390  
Available-for-Sale, Number of Securities | Security 13