Oil and Gas Reserve Information (Details) Mcf in Thousands, MBbls in Thousands	12 Months Ended
	Dec. 31, 2019 $ / WTIperBbl $ / CIGperMbtu Mcf MBbls	Dec. 31, 2018 $ / WTIperBbl $ / CIGperMbtu Mcf MBbls	Dec. 31, 2017 $ / WTIperBbl $ / CIGperMbtu Mcf MBbls
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Ending Balance	276,611
Downward revision of proved undeveloped reserves	57,212
Downward revision due to decreases in natural gas prices	54,520,000
Proved developed reserve	276,611	318,210	206,446
Proved undeveloped reserve	0	105,668	138,750
Company
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Starting Balance	119	500	420
Revisions of quantity estimate	270	(341)	139
Extensions and discoveries	0	0	0
Acquisitions and divestitures	(48)
Production	(26)	(40)	(59)
Ending Balance	315	119	500
Increase (decrease) in estimated proved reserves	(147,267)	78,682	22,095
Increase in estimated proved reserves, percentage	(35.00%)	23.00%	(6.00%)
Proved developed reserve		119	500
Proved undeveloped reserve	0	0	0
Company's Share of Laramie Energy
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Starting Balance	423,759	344,696	366,871
Revisions of quantity estimate	(111,732)	85,875	3
Extensions and discoveries	0	0	0
Acquisitions and divestitures	0	23,609	0
Production	(35,731)	(30,421)	(22,178)
Ending Balance	276,296	423,759	344,696
Increase (decrease) in estimated proved reserves	(35,731)
Additions of proved undeveloped reserves		60,679,000
Positive revisions from converted proved developed reserves		11,614,000
Positive revisions due to performance revisions		13,582,000
Proved developed reserve	276,296	318,091	205,946
Proved undeveloped reserve	0	105,668	138,750
Natural Gas
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Ending Balance	238,451
Proved developed reserve	238,451	256,452	174,856
Proved undeveloped reserve	0	81,428	118,578
Natural Gas | Company
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Starting Balance	89	392	330
Revisions of quantity estimate	222	(269)	109
Extensions and discoveries	0	0	0
Acquisitions and divestitures	(30)
Production	(20)	(34)	(47)
Ending Balance	261	89	392
Proved developed reserve		89	392
Proved undeveloped reserve	0	0	0
Base pricing, before adjustments for contractual differentials | $ / CIGperMbtu	2.04	2.47	2.68
Natural Gas | Company's Share of Laramie Energy
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Starting Balance	337,791	293,042	309,802
Revisions of quantity estimate	(69,924)	47,871	1,344
Extensions and discoveries	0	0	0
Acquisitions and divestitures	0	22,391	0
Production	(29,677)	(25,513)	(18,104)
Ending Balance	238,190	337,791	293,042
Proved developed reserve	238,190	256,363	174,464
Proved undeveloped reserve	0	81,428	118,578
Oil
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Ending Balance | MBbls	939
Proved developed reserve | MBbls	939	1,424	665
Proved undeveloped reserve | MBbls	0	325	449
Oil | Company
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Starting Balance | MBbls	4	7	7
Revisions of quantity estimate | MBbls	1	(2)	2
Extensions and discoveries | MBbls	0	0	0
Acquisitions and divestitures | MBbls	(3)
Production | MBbls	(1)	(1)	(2)
Ending Balance | MBbls	1	4	7
Proved developed reserve | MBbls		4	7
Proved undeveloped reserve | MBbls	0	0	0
Base pricing, before adjustments for contractual differentials | $ / WTIperBbl	55.85	65.56	51.34
Oil | Company's Share of Laramie Energy
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Starting Balance | MBbls	1,745	1,107	967
Revisions of quantity estimate | MBbls	(681)	732	211
Extensions and discoveries | MBbls	0	0	0
Acquisitions and divestitures | MBbls	0	12	0
Production | MBbls	(126)	(106)	(71)
Ending Balance | MBbls	938	1,745	1,107
Proved developed reserve | MBbls	938	1,420	658
Proved undeveloped reserve | MBbls	0	325	449
Natural Gas Liquids
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Ending Balance | MBbls	5,421
Proved developed reserve | MBbls	5,421	8,869	4,600
Proved undeveloped reserve | MBbls	0	3,715	2,913
Natural Gas Liquids | Company
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Starting Balance | MBbls	1	11	8
Revisions of quantity estimate | MBbls	7	(10)	3
Extensions and discoveries | MBbls	0	0	0
Acquisitions and divestitures | MBbls	0
Production | MBbls	0	0	0
Ending Balance | MBbls	8	1	11
Proved developed reserve | MBbls		1	11
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 Flows Relating to Proved Oil and Gas Reserves [Roll Forward]
Starting Balance | MBbls	12,583	7,502	8,544
Revisions of quantity estimate | MBbls	(6,287)	5,602	(434)
Extensions and discoveries | MBbls	0	0	0
Acquisitions and divestitures | MBbls	0	191	0
Production | MBbls	(883)	(712)	(608)
Ending Balance | MBbls	5,413	12,583	7,502
Proved developed reserve | MBbls	5,413	8,868	4,589
Proved undeveloped reserve | MBbls	0	3,715	2,913