Annual report pursuant to Section 13 and 15(d)

Derivative Instruments - Schedule of Derivative Instruments in Statement of Financial Position (Details)

v3.6.0.2
Derivative Instruments - Schedule of Derivative Instruments in Statement of Financial Position (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
General Discussion of Derivative Instruments and Hedging Activities [Abstract]    
Short-term derivative instruments - assets $ 3,488 $ 142,794
Long-term derivative instruments 5,696 51,088
Short-term derivative instruments - liability 119,219 437
Long-term derivative instruments - liability $ 26,759 $ 6,935