Annual report pursuant to Section 13 and 15(d)

401k Savings Plan - Additional Information (Detail)

v3.21.1
401k Savings Plan - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
401k Savings Plan [Member]      
Defined Contribution Plan Disclosure [Line Items]      
Expense for matching contributions $ 126,000 $ 117,000 $ 104,000