Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Project Development Costs?? (Details)

v3.20.4
Summary of Significant Accounting Policies - Project Development Costs  (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Accounting Policies [Abstract]    
Product development cost included in other long-term assets $ 1,543 $ 1,080