Annual report pursuant to Section 13 and 15(d)

Derivative Financial Instruments - Estimated Fair Value of Derivative Contracts (Details)

v3.6.0.2
Derivative Financial Instruments - Estimated Fair Value of Derivative Contracts (Details)
$ in Thousands
Dec. 31, 2015
USD ($)
Prepaid and Other Assets - Current  
Derivatives Fair Value [Line Items]  
Fair value of commodity derivative contracts $ 7,672