Annual report pursuant to Section 13 and 15(d)

Segment Information (Narrative) (Details)

v3.20.4
Segment Information (Narrative) (Details) - segment
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Concentration Risk [Line Items]    
Number of reportable operating segments 2  
Sales Revenue, Net [Member] | Glencore [Member]    
Concentration Risk [Line Items]    
Concentration risk, percentage   6.00%
Sales Revenue, Net [Member] | Mercuria [Member]    
Concentration Risk [Line Items]    
Concentration risk, percentage 14.00% 94.00%
Sales Revenue, Net [Member] | ExxonMobil [Member]    
Concentration Risk [Line Items]    
Concentration risk, percentage 86.00%