Note 4 - Long-term Debt (Details Textual) | Jun. 25, 2020USD ($) | Nov. 13, 2019USD ($) | Jun. 20, 2018USD ($) | Jun. 30, 2020USD ($) | Jun. 24, 2020USD ($) | Mar. 31, 2020USD ($) | Dec. 31, 2019USD ($) |
Long-term Debt, Total | | | | $ 203,071,000 | | | $ 192,718,000 |
Line of Credit [Member] | First Lien Credit Facility [Member] | | | | | | | |
Long-term Line of Credit, Total | | | | $ 102,000,000 | | | |
Debt Instrument, Spread on Elected Variable Rate | | | | 0.50% | | | |
Debt Instrument, Debt Default, Basis Spread on Variable Rate | | | | 3.00% | | | |
Line of Credit Facility, Interest Rate at Period End | | | | 3.70% | | | |
Debt Instrument, Collateral Eligible, Minimum Percent of PV-9 of Proven Reserves Required | | | | 90.00% | | | |
Debt Instrument, Collateral Eligible, Minimum Percent of PV-9 of PDP Reserves Required | | | | 95.00% | | | |
Debt Instrument, Covenant, Working Capital Reserve | $ 3,000,000 | | | | | | |
Debt Instrument, Covenant, Maximum Capital Expenditures | $ 3,000,000 | | | | | | |
Debt Instrument, Covenant, Minimum Asset Coverage Ratio for Capital Expenditures | 1.60 | | | | | | |
Debt Instrument, Covenant, Maximum Line of Credit Outstanding for Capital Expenditures | $ 50,000,000 | | | | | | |
Debt Instrument, Covenant, Maximum Outstanding and Undisputed Accounts Payable | 7,500,000 | | | | | | |
Debt Instrument, Covenant, Maximum Undisputed Accounts Payable Outstanding with 60 to 90 Days | 2,000,000 | | | | | | |
Debt Instrument, Covenant, Maximum Undisputed Accounts Payable Outstanding with Over 90 Days | 1,000,000 | | | | | | |
Debt Instrument, Covenant, Maximum Legal and Professional Fees Excluded from General and Administrative Expense Limitations | 1,000,000 | | | | | | |
Debt Instrument, Covenant, Maximum Additional Subordinated Debt Allowed to Finance Capital Expenditures | 25,000,000 | | | | | | |
Line of Credit Facility, Current Borrowing Capacity | 102,000,000 | | | | $ 135,000,000 | | |
Line of Credit [Member] | First Lien Credit Facility [Member] | General and Administrative Expenses for Quarter Ending June 30, 2020 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Quarterly General and Administrative Expenses | 9,000,000 | | | | | | |
Line of Credit [Member] | First Lien Credit Facility [Member] | General and Administrative Expenses for Quarter Ending September 30, 2020 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Quarterly General and Administrative Expenses | 8,250,000 | | | | | | |
Line of Credit [Member] | First Lien Credit Facility [Member] | General and Administrative Expenses for Quarter Ending December 31, 2020 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Quarterly General and Administrative Expenses | 6,900,000 | | | | | | |
Line of Credit [Member] | First Lien Credit Facility [Member] | General and Administrative Expenses for Year End December 31, 2021 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Yearly General and Administrative Expenses | 6,500,000 | | | | | | |
Line of Credit [Member] | First Lien Credit Facility [Member] | General and Administrative Expenses After Year End December 31, 2021 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Yearly General and Administrative Expenses | $ 5,000,000 | | | | | | |
Line of Credit [Member] | First Lien Credit Facility [Member] | Minimum [Member] | | | | | | | |
Debt Instrument, Spread on Elected Variable Rate | | | | 2.50% | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 1.50% | | | |
Line of Credit [Member] | First Lien Credit Facility [Member] | Maximum [Member] | | | | | | | |
Debt Instrument, Spread on Elected Variable Rate | | | | 3.50% | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 2.50% | | | |
Debt Instrument, Covenant, Total Debt to EBITDAX Ratio | 2.75 | | | | | | |
Debt Instrument, Covenant, Asset Coverage Ratio, Current | 1.15 | | | | | | |
Debt Instrument, Covenant, Asset Coverage Ratio, Noncurrent | 1.25 | | | | | | |
Line of Credit [Member] | Second Lien Credit Facility [Member] | | | | | | | |
Long-term Line of Credit, Total | | | | | | $ 102,000,000 | |
Debt Instrument, Covenant, Maximum Outstanding and Undisputed Accounts Payable | $ 7,500,000 | | | | | | |
Debt Instrument, Covenant, Maximum Undisputed Accounts Payable Outstanding with 60 to 90 Days | 2,000,000 | | | | | | |
Debt Instrument, Covenant, Maximum Undisputed Accounts Payable Outstanding with Over 90 Days | 1,000,000 | | | | | | |
Line of Credit Facility, Maximum Borrowing Capacity | | $ 100,000,000 | | | | | |
Proceeds from Lines of Credit, Total | | $ 95,000,000 | | | | | |
Debt Instrument, Collateral Eligible, Minimum Percent of PV-9 Proven Reserves | | 90.00% | | | | | |
Debt Instrument, Collateral Eligible, Minimum Percent of PV-9 Required PDP Reserves | | 95.00% | | | | | |
Line of Credit [Member] | Second Lien Credit Facility [Member] | General and Administrative Expenses for Quarter Ending June 30, 2020 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Quarterly General and Administrative Expenses | 9,000,000 | | | | | | |
Line of Credit [Member] | Second Lien Credit Facility [Member] | General and Administrative Expenses for Quarter Ending September 30, 2020 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Quarterly General and Administrative Expenses | 8,250,000 | | | | | | |
Line of Credit [Member] | Second Lien Credit Facility [Member] | General and Administrative Expenses for Year End December 31, 2021 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Yearly General and Administrative Expenses | 6,500,000 | | | | | | |
Line of Credit [Member] | Second Lien Credit Facility [Member] | General and Administrative Expenses After Year End December 31, 2021 [Member] | | | | | | | |
Debt Instrument, Covenant, Maximum Yearly General and Administrative Expenses | $ 5,000,000 | | | | | | |
Line of Credit [Member] | Second Lien Credit Facility [Member] | Maximum [Member] | | | | | | | |
Debt Instrument, Covenant, Asset Coverage Ratio, Noncurrent, Year Two | 1.45 | | | | | | |
Debt Instrument, Covenant, Asset Coverage Ratio, Noncurrent, after Year Two | 1.55 | | | | | | |
Construction Loans [Member] | | | | | | | |
Debt Instrument, Interest Rate, Stated Percentage | | | 4.90% | | | | |
Debt Instrument, Periodic Payment, Total | | | $ 35,672 | | | | |
Long-term Debt, Total | | | | $ 3,000,000 | | | $ 3,100,000 |