Information Regarding Proved Oil and Gas Reserves (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Discounted future net cash flows	$ 319,232	$ 216,393	$ 141,427	$ 39,797
Company
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Future net cash flows	398	1,802	1,154
Production	123	902	713
Development and abandonment	35	0	2
Income taxes	0	0	0
Future net cash flows	240	900	439
10% discount factor	(110)	(328)	(154)
Discounted future net cash flows	130	572	285	192
Company's Share of Laramie Energy
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Future net cash flows	1,283,890	1,026,005	905,607
Production	583,112	491,748	462,684
Development and abandonment	93,546	109,248	136,224
Income taxes	0	0	0
Future net cash flows	607,232	425,009	306,699
10% discount factor	(288,130)	(209,188)	(165,557)
Discounted future net cash flows	$ 319,102	$ 215,821	$ 141,142	$ 39,605