Annual report pursuant to Section 13 and 15(d)

Segment Information (Narrative) (Details)

v3.6.0.2
Segment Information (Narrative) (Details)
12 Months Ended
Dec. 31, 2016
segment
Concentration Risk [Line Items]  
Number of reportable operating segments 3
Sales Revenue, Net [Member] | Glencore U.K. [Member]  
Concentration Risk [Line Items]  
Concentration Risk, Percentage 99.90%