XML 386 R57.htm IDEA: XBRL DOCUMENT v3.20.4
Other Financial Information - Additional Information (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]      
Depreciation expense $ 4.3 $ 5.1 $ 7.4
Long-term purchase commitment $ 117.0