Summary of Significant Accounting Policies (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($) mi² BarrelsofOilPerDay Customer Contract shares bbl	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) Contract shares
Nature of Operations and Principles of Consolidation [Abstract]
Primary area of operation (in square miles) | mi²	1,000
Components of Prepayments and Other [Abstract]
Cash collateral deposits for commodity purchases	$ 2,000		$ 167,000
Insurance premiums	1,551,000		1,609,000
Rents, license and other	698,000		813,000
Prepayments, total	2,251,000		2,589,000
Property, Plant and Equipment [Line Items]
Total Non-producing Leasehold Costs	231,000		231,000
Fair value measurements for producing and non-producing oil and gas properties that were subject to fair value impairment [Abstract]
Impairment	29,000	$ 208,000
Cash Deposits and Other Assets [Abstract]
Insurance collateral deposits	6,403,000		6,531,000
State collateral deposits	142,000		140,000
Materials and supplies	317,000		292,000
Cash deposits and other	6,862,000		$ 6,963,000
Revenue Recognition [Abstract]
Revenue gross-up	$ 75,927,000	130,222,000
Concentration of Credit Risk [Line Items]
Maximum percentage of US demand supplied by company	1.00%
Statement of Cash Flows [Abstract]
Interest paid	$ 0	4,000
Federal and state tax paid	105,000	1,081,000
Property and equipment additions	$ 350,000	566,000
Earnings Per Share [Abstract]
Weighted average number of shares outstanding (in shares) | shares	4,217,596		4,217,596
Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	20 years
Customer Concentration Risk [Member] | Minimum [Member]
Concentration of Credit Risk [Line Items]
Number of customers | Customer	3
Customer Concentration Risk [Member] | Maximum [Member]
Concentration of Credit Risk [Line Items]
Number of customers | Customer	5
Producing Property Impairments [Member]
Fair value measurements for producing and non-producing oil and gas properties that were subject to fair value impairment [Abstract]
Impairment	$ 1,000	203,000
Non-Producing Property Impairments [Member]
Property, Plant and Equipment [Line Items]
Capitalized costs for non-producing oil and gas leasehold interests specified as percentage of total costs	3.00%
Fair value measurements for producing and non-producing oil and gas properties that were subject to fair value impairment [Abstract]
Impairment	$ 28,000	5,000
Napoleonville, Louisiana Acreage [Member]
Property, Plant and Equipment [Line Items]
Total Non-producing Leasehold Costs	49,000		$ 49,000
Wyoming and Other Acreage [Member]
Property, Plant and Equipment [Line Items]
Total Non-producing Leasehold Costs	$ 182,000		$ 182,000
Onshore Leasehold [Member]
Property, Plant and Equipment [Line Items]
Onshore Leasehold Period	3 years
Wells Fargo Bank [Member] | Standby Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 60,000,000
Stand-by letters of credit	$ 1,000,000	$ 7,000,000
Current ratio	1.1
Commodity Contract [Member]
Fair Value Forward Hydrocarbon Commodity Contracts at Gross Valuation [Abstract]
Number of contracts held | Contract	4		1
Commodity Contract [Member] | January 2016 through March 2016 [Member]
Fair Value Forward Hydrocarbon Commodity Contracts at Gross Valuation [Abstract]
Volume committed per day under commodity purchase and sale contract (in barrels per day) | BarrelsofOilPerDay	65
Commodity Contract [Member] | April 2016 through March 2017 [Member]
Fair Value Forward Hydrocarbon Commodity Contracts at Gross Valuation [Abstract]
Volume committed per day under commodity purchase and sale contract (in barrels per day) | BarrelsofOilPerDay	65
Commodity Contract [Member] | June 2016 [Member]
Fair Value Forward Hydrocarbon Commodity Contracts at Gross Valuation [Abstract]
Total volume committed under commodity purchase and sale contract (in barrels or mmbtu) | bbl	67,000
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets [Member]
Fair Value Forward Hydrocarbon Commodity Contracts at Gross Valuation [Abstract]
Asset Derivatives	$ 20,000		$ 0
Liability Derivatives	0		0
Less Counterparty Offsets	0		0
Net Value	20,000		0
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Fair Value Forward Hydrocarbon Commodity Contracts at Gross Valuation [Abstract]
Asset Derivatives	0		0
Liability Derivatives	0		0
Less Counterparty Offsets	0		0
Net Value	0		0
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities [Member]
Fair Value Forward Hydrocarbon Commodity Contracts at Gross Valuation [Abstract]
Asset Derivatives	0		0
Liability Derivatives	373,000		195,000
Less Counterparty Offsets	0		0
Net Value	373,000		195,000
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Fair Value Forward Hydrocarbon Commodity Contracts at Gross Valuation [Abstract]
Asset Derivatives	0		0
Liability Derivatives	0		0
Less Counterparty Offsets	0		0
Net Value	$ 0		0
Revenue [Member]
Concentration of Credit Risk [Line Items]
Percentage of revenues from one customer which loss would not have material effect	10.00%
Revenue [Member] | Customer Concentration Risk [Member]
Concentration of Credit Risk [Line Items]
Concentration risk, percentage	50.00%
Accounts Receivable [Member]
Concentration of Credit Risk [Line Items]
Industry practice payment of receivables	20 days
Accounts Receivable [Member] | Product Concentration Risk [Member]
Concentration of Credit Risk [Line Items]
Concentration risk, percentage	90.00%
Accounting Standard Update 2016-02 [Member]
Recent Accounting Pronouncement [Abstract]
Long-term non-cancellable operating lease arrangements			$ 12,393,000