Income Taxes - Additional Information (Detail) - USD ($) |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
Income Taxes [Line Items] | |||
Securities transactions income tax (benefit) expense | $ (82,000) | $ 171,000 | $ 10,000 |
Federal tax rate, percentage | 21.00% | 21.00% | 21.00% |
Recognition of interest and penalties related to unrecognized tax benefits | $ 0 | $ 0 | $ 0 |
Earliest Tax Year [Member] | |||
Income Taxes [Line Items] | |||
Year under examination | 2017 | 2018 | |
Latest Tax Year [Member] | |||
Income Taxes [Line Items] | |||
Year under examination | 2019 | 2023 |