Annual report pursuant to Section 13 and 15(d)

Long-term Supply Contract (Details)

v3.20.4
Long-term Supply Contract (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 01, 2014
Commitments and Contingencies Disclosure [Abstract]        
Supply agreement liability       $ 27,300
Gain on contract termination $ 0 $ 0 $ 20,612