Annual report pursuant to Section 13 and 15(d)

Employee benefit plans (Details)

v3.21.1
Employee benefit plans (Details)
12 Months Ended
Dec. 31, 2020
USD ($)
plan
Dec. 31, 2019
USD ($)
Retirement Benefits [Abstract]    
Number of qualified defined contribution 401(k) plans | plan 2  
Contributions expense | $ $ 200,000 $ 100,000