Annual report pursuant to Section 13 and 15(d)

Segment Information (Narrative) (Details)

v3.20.1
Segment Information (Narrative) (Details)
12 Months Ended
Dec. 31, 2019
segment
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 94.00%