Annual report pursuant to Section 13 and 15(d)

Securities - Additional Information (Detail)

v3.22.0.1
Securities - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]      
Net gains (losses) in earnings resulting from sale of securities $ (499,000) $ 15,712,000 $ 1,295,000
Net unrealized gains (losses) recorded in comprehensive income (123,000) 15,300,000 $ (586,000)
Available for sale securities pledged as collateral $ 34,700,000 $ 27,300,000  
Minimum | U.S. Government and its Agencies      
Debt Securities, Available-for-sale [Line Items]      
Holdings of securities as percentage of share holders' equity 10.00%