Quarterly report pursuant to Section 13 or 15(d)

Securities - Available for Sale Securities, Continuous Unrealized Loss Position, Fair value (Detail)

v3.20.2
Securities - Available for Sale Securities, Continuous Unrealized Loss Position, Fair value (Detail)
$ in Thousands
Jun. 30, 2020
USD ($)
Security
Dec. 31, 2019
USD ($)
Security
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (630) $ (318)
Available-for-Sale Within One Year, Estimated Fair Value $ 301,567 $ 100,916
Available-for-Sale Within One Year, Number of Securities | Security 44 33
Available-for-Sale More than One Year, Gross Unrealized Loss   $ (483)
Available-for-Sale More than One Year, Estimated Fair Value   $ 61,690
Available-for-Sale More than One Year, Number of Securities | Security   51
Available-for-Sale, Gross Unrealized Loss $ (630) $ (801)
Available-for-Sale, Estimated Fair Value $ 301,567 $ 162,606
Available-for-Sale, Number of Securities | Security 44 84
U.S. Treasury securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Estimated Fair Value $ 29,988  
Available-for-Sale Within One Year, Number of Securities | Security 4  
Available-for-Sale, Estimated Fair Value $ 29,988  
Available-for-Sale, Number of Securities | Security 4  
Mortgage-backed securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (437) $ (186)
Available-for-Sale Within One Year, Estimated Fair Value $ 192,403 $ 51,261
Available-for-Sale Within One Year, Number of Securities | Security 23 17
Available-for-Sale More than One Year, Gross Unrealized Loss   $ (161)
Available-for-Sale More than One Year, Estimated Fair Value   $ 18,757
Available-for-Sale More than One Year, Number of Securities | Security   14
Available-for-Sale, Gross Unrealized Loss $ (437) $ (347)
Available-for-Sale, Estimated Fair Value $ 192,403 $ 70,018
Available-for-Sale, Number of Securities | Security 23 31
Collateralized mortgage obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (176) $ (112)
Available-for-Sale Within One Year, Estimated Fair Value $ 46,693 $ 41,419
Available-for-Sale Within One Year, Number of Securities | Security 12 14
Available-for-Sale More than One Year, Gross Unrealized Loss   $ (320)
Available-for-Sale More than One Year, Estimated Fair Value   $ 39,936
Available-for-Sale More than One Year, Number of Securities | Security   36
Available-for-Sale, Gross Unrealized Loss $ (176) $ (432)
Available-for-Sale, Estimated Fair Value $ 46,693 $ 81,355
Available-for-Sale, Number of Securities | Security 12 50
Debt securities    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (17) $ (20)
Available-for-Sale Within One Year, Estimated Fair Value $ 32,483 $ 8,235
Available-for-Sale Within One Year, Number of Securities | Security 5 2
Available-for-Sale More than One Year, Gross Unrealized Loss   $ (3)
Available-for-Sale More than One Year, Estimated Fair Value   $ 2,997
Available-for-Sale More than One Year, Number of Securities | Security   1
Available-for-Sale, Gross Unrealized Loss $ (17) $ (22)
Available-for-Sale, Estimated Fair Value $ 32,483 $ 11,233
Available-for-Sale, Number of Securities | Security 5 3
Total U.S. government agency and sponsored agency obligations    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ (630) $ (318)
Available-for-Sale Within One Year, Estimated Fair Value $ 271,579 $ 100,916
Available-for-Sale Within One Year, Number of Securities | Security 40 33
Available-for-Sale More than One Year, Gross Unrealized Loss   $ (483)
Available-for-Sale More than One Year, Estimated Fair Value   $ 61,690
Available-for-Sale More than One Year, Number of Securities | Security   51
Available-for-Sale, Gross Unrealized Loss $ (630) $ (801)
Available-for-Sale, Estimated Fair Value $ 271,579 $ 162,606
Available-for-Sale, Number of Securities | Security 40 84