Commodity Derivatives (Details 2) - Commodity derivative contracts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Settlement gain (loss)	$ 3,543	$ (3,848)
Unrealized (loss) gain	(499)	8,742
Total commodity derivative gain	$ 3,044	$ 4,894