Information Regarding Proved Oil and Gas Reserves (Details) Mcf in Thousands, MBbls in Thousands	12 Months Ended
	Dec. 31, 2015 $ / WTIperBbl $ / CIGperMbtu Mcf MBbls	Dec. 31, 2014 $ / WTIperBbl $ / CIGperMbtu Mcf MBbls	Dec. 31, 2013 $ / WTIperBbl $ / CIGperMbtu Mcf MBbls
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Ending Balance	161,065,000
Proved developed reserve	78,797	58,546	57,907
Proved undeveloped reserve	82,268	195,193	178,680
Company
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Beginning Balance	1,165,000	2,078,000	2,163,000
Revisions of quantity estimate	(630,000)	(211,000)	557,000
Extensions and discoveries	0	14,000	25,000
Production	(311,000)	(716,000)	(667,000)
Ending Balance	224,000	1,165,000	2,078,000
Proved developed reserve	224	1,165	2,078
Proved undeveloped reserve	0	0	0
Increase in estimated proved reserves	(92,674,000)	17,152,000	68,718,000
Increase in estimated proved reserves, percentage	(36.50%)	7.00%	41.00%
Company's Share of Laramie Energy
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Beginning Balance	252,574,000	234,509,000	165,706,000
Revisions of quantity estimate	(117,752,000)	(1,054,000)	(15,900,000)
Extensions and discoveries	38,869,000	24,808,000	89,688,000
Acquisitions and divestitures	(7,091,000)
Production	(5,759,000)	(5,689,000)	(4,985,000)
Ending Balance	160,841,000	252,574,000	234,509,000
Proved developed reserve	78,573	57,381	55,829
Proved undeveloped reserve	82,268	195,193	178,680
Increase in estimated proved reserves	(117,752,000)	24,808,000	89,688,000
Natural Gas
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Ending Balance	133,741,000
Proved developed reserve	65,687	49,456	45,734
Proved undeveloped reserve	68,054	162,895	141,525
Natural Gas | Company
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Beginning Balance	601,000	662,000	446,000
Revisions of quantity estimate	(330,000)	65,000	460,000
Extensions and discoveries	0	8,000	9,000
Production	(83,000)	(134,000)	(253,000)
Ending Balance	188,000	601,000	662,000
Proved developed reserve	188	601	662
Proved undeveloped reserve	0	0	0
Base Pricing, before adjustments for contractual differentials | $ / CIGperMbtu	2.39	4.36	3.53
Natural Gas | Company's Share of Laramie Energy
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Beginning Balance	211,750,000	186,597,000	122,650,000
Revisions of quantity estimate	(99,548,000)	8,876,000	(3,944,000)
Extensions and discoveries	32,041,000	21,108,000	71,921,000
Acquisitions and divestitures	(5,945,000)
Production	(4,745,000)	(4,831,000)	(4,030,000)
Ending Balance	133,553,000	211,750,000	186,597,000
Proved developed reserve	65,499	48,855	45,072
Proved undeveloped reserve	68,054	162,895	141,525
Oil
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Ending Balance | MBbls	509
Proved developed reserve | MBbls	254	272	401
Proved undeveloped reserve | MBbls	255	533	419
Oil | Company
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Beginning Balance | MBbls	77	236	286
Revisions of quantity estimate | MBbls	(35)	(67)	16
Extensions and discoveries | MBbls	0	1	3
Production | MBbls	(36)	(93)	(69)
Ending Balance | MBbls	6	77	236
Proved developed reserve | MBbls	6	77	236
Proved undeveloped reserve | MBbls	0	0	0
Base Pricing, before adjustments for contractual differentials | $ / WTIperBbl	50.28	94.99	96.91
Oil | Company's Share of Laramie Energy
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Beginning Balance | MBbls	728	584	831
Revisions of quantity estimate | MBbls	(316)	34	(404)
Extensions and discoveries | MBbls	131	128	173
Acquisitions and divestitures | MBbls	(20)
Production | MBbls	(20)	(18)	(16)
Ending Balance | MBbls	503	728	584
Proved developed reserve | MBbls	248	195	165
Proved undeveloped reserve | MBbls	255	533	419
Natural Gas Liquids
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Ending Balance | MBbls	4,045
Proved developed reserve | MBbls	1,931	1,243	1,627
Proved undeveloped reserve | MBbls	2,114	4,850	5,774
Natural Gas Liquids | Company
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Beginning Balance | MBbls	17	0	0
Revisions of quantity estimate | MBbls	(15)	21	0
Extensions and discoveries | MBbls	0	0	0
Production | MBbls	(2)	(4)	0
Ending Balance | MBbls	0	17	0
Proved developed reserve | MBbls	0	17	0
Proved undeveloped reserve | MBbls	0	0	0
Natural Gas Liquids | Company's Share of Laramie Energy
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]
Beginning Balance | MBbls	6,076	7,401	6,345
Revisions of quantity estimate | MBbls	(2,718)	(1,689)	(1,589)
Extensions and discoveries | MBbls	1,007	489	2,788
Acquisitions and divestitures | MBbls	(171)
Production | MBbls	(149)	(125)	(143)
Ending Balance | MBbls	4,045	6,076	7,401
Proved developed reserve | MBbls	1,931	1,226	1,627
Proved undeveloped reserve | MBbls	2,114	4,850	5,774