Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / oz	Dec. 31, 2014 USD ($) $ / oz	Dec. 31, 2013 USD ($) $ / oz
Property, Plant and Equipment [Line Items]
Drilling and Related Costs Capitalized | $	$ 6,000	$ 8,900
Write-downs | $	$ 313,337	$ 1,472,721	$ 772,993
Long-Lived Assets, Impairment Testing, Commodity, Silver, Price per Ounce | $ / oz	17.50	19.00	25.00
Long-Lived Assets, Impairment Testing, Commodity, Gold, Price per Ounce | $ / oz	1,200	1,275	1,450
Maximum [Member]
Property, Plant and Equipment [Line Items]
Fair Value Inputs, Discount Rate	11.00%
Minimum [Member]
Property, Plant and Equipment [Line Items]
Fair Value Inputs, Discount Rate	7.50%
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years