Derivative Financial Instruments (Details 1) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commodity Derivatives [Abstract]
Realized (loss) gain on commodity derivatives - natural gas									$ 0	$ 146,801	$ (48,170)
Realized (loss) gain on commodity derivatives - crude oil									0	0	506
Unrealized loss (gain) on commodity derivatives									0	(104,190)	130,066
Gain loss on commodity derivatives	$ 0	$ 0	$ 0	$ 0	$ 2	$ 9,390	$ (3,646)	$ 36,865	$ 0	$ 42,611	$ 82,402