Derivative Instruments (Company's Outstanding Commodity Derivatives) (Details)	9 Months Ended
	Sep. 30, 2015 oz $ / oz
Fourth Quarter 2015 [Member] | Platinum [Member]
Derivative [Line Items]
Ounces	34,967
Average Price/Ounce | $ / oz	1,003
Fourth Quarter 2015 [Member] | Palladium [Member]
Derivative [Line Items]
Ounces	49,347
Average Price/Ounce | $ / oz	630
Fourth Quarter 2015 [Member] | Rhodium [Member]
Derivative [Line Items]
Ounces	6,194
Average Price/Ounce | $ / oz	841
First Quarter 2016 [Member] | Platinum [Member]
Derivative [Line Items]
Ounces	3,247
Average Price/Ounce | $ / oz	968
First Quarter 2016 [Member] | Palladium [Member]
Derivative [Line Items]
Ounces	4,632
Average Price/Ounce | $ / oz	607
First Quarter 2016 [Member] | Rhodium [Member]
Derivative [Line Items]
Ounces	1,195
Average Price/Ounce | $ / oz	764