Credit Facility	12 Months Ended
Dec. 31, 2018
Debt Disclosure [Abstract]
Credit Facility	CREDIT FACILITY The Partnership maintains a senior secured revolving credit agreement, as amended, (the “Credit Facility”). The Credit Facility has a maximum credit amount of $1.0 billion. The amount of the borrowing base is derived from the value of the Partnership’s oil and natural gas properties determined by the lender syndicate using pricing assumptions that often differ from the current market for future prices. Drawings on the Credit Facility are used for the acquisition of oil and natural gas properties and for other general business purposes. Effective October 31, 2016 the borrowing base was $500.0 million and, effective April 25, 2017, the borrowing base redetermination resulted in an increase to $550.0 million. On November 1, 2017, the Partnership amended and restated the credit agreement to extend the maturity thereof for a term of five years, create a swingline facility that permits short-term borrowings on same-day notice, and make other changes to the hedging and restrictive covenants. There was no change to the borrowing base. The Credit Facility now terminates on November 1, 2022. Effective May 4, 2018, the borrowing base redetermination resulted in an increase to $600.0 million and, effective October 31, 2018, the borrowing base was further increased to $675.0 million. Effective October 31, 2016, borrowings under the Credit Facility bore interest at LIBOR plus a margin between 2.00% and 3.00%, or the Prime Rate plus a margin between 1.00% and 2.00%, with the margin depending on the borrowing base utilization of the loan. Effective October 31, 2018, the LIBOR margin was reduced to between 1.75% and 2.75% and the Prime Rate margin was reduced to between 0.75% and 1.75%. The weighted-average interest rate of the Credit Facility was 4.76% and 4.06% as of December 31, 2018 and 2017, respectively. Accrued interest is payable at the end of each calendar quarter or at the end of each interest period, unless the interest period is longer than 90 days in which case interest is payable at the end of every 90-day period. In addition, a commitment fee is payable at the end of each calendar quarter based on either a rate of 0.375% if the borrowing base utilization percentage is less than 50%, or 0.500% per annum if the borrowing base utilization percentage is equal to or greater than 50%. The Credit Facility is secured by substantially all of the Partnership’s oil and natural gas production and assets. The Credit Facility contains various limitations on future borrowings, leases, hedging, and sales of assets. Additionally, the Credit Facility requires the Partnership to maintain a current ratio of not less than 1.0:1.0 and a ratio of total debt to EBITDAX (Earnings before Interest, Taxes, Depreciation, Amortization, and Exploration) of not more than 3.5:1.0. As of December 31, 2018, the Partnership was in compliance with all financial covenants in the Credit Facility. The aggregate principal balance outstanding was $410.0 million and $388.0 million at December 31, 2018 and 2017, respectively. The unused portion of the available borrowings under the Credit Facility were $265.0 million and $162.0 million at December 31, 2018 and 2017, respectively.

CREDIT FACILITY

The Partnership maintains a senior secured revolving credit agreement, as amended, (the “Credit Facility”). The Credit Facility has a maximum credit amount of $1.0 billion. The amount of the borrowing base is derived from the value of the Partnership’s oil and natural gas properties determined by the lender syndicate using pricing assumptions that often differ from the current market for future prices.

Drawings on the Credit Facility are used for the acquisition of oil and natural gas properties and for other general business purposes. Effective October 31, 2016 the borrowing base was $500.0 million and, effective April 25, 2017, the borrowing base redetermination resulted in an increase to $550.0 million. On November 1, 2017, the Partnership amended and restated the credit agreement to extend the maturity thereof for a term of five years, create a swingline facility that permits short-term borrowings on same-day notice, and make other changes to the hedging and restrictive covenants. There was no change to the borrowing base. The Credit Facility now terminates on November 1, 2022. Effective May 4, 2018, the borrowing base redetermination resulted in an increase to $600.0 million and, effective October 31, 2018, the borrowing base was further increased to $675.0 million.

Effective October 31, 2016, borrowings under the Credit Facility bore interest at LIBOR plus a margin between 2.00% and 3.00%, or the Prime Rate plus a margin between 1.00% and 2.00%, with the margin depending on the borrowing base utilization of the loan. Effective October 31, 2018, the LIBOR margin was reduced to between 1.75% and 2.75% and the Prime Rate margin was reduced to between 0.75% and 1.75%.

The weighted-average interest rate of the Credit Facility was 4.76% and 4.06% as of December 31, 2018 and 2017, respectively. Accrued interest is payable at the end of each calendar quarter or at the end of each interest period, unless the interest period is longer than 90 days in which case interest is payable at the end of every 90-day period. In addition, a commitment fee is payable at the end of each calendar quarter based on either a rate of 0.375% if the borrowing base utilization percentage is less than 50%, or 0.500% per annum if the borrowing base utilization percentage is equal to or greater than 50%. The Credit Facility is secured by substantially all of the Partnership’s oil and natural gas production and assets.

The Credit Facility contains various limitations on future borrowings, leases, hedging, and sales of assets. Additionally, the Credit Facility requires the Partnership to maintain a current ratio of not less than 1.0:1.0 and a ratio of total debt to EBITDAX (Earnings before Interest, Taxes, Depreciation, Amortization, and Exploration) of not more than 3.5:1.0. As of December 31, 2018, the Partnership was in compliance with all financial covenants in the Credit Facility.

The aggregate principal balance outstanding was $410.0 million and $388.0 million at December 31, 2018 and 2017, respectively. The unused portion of the available borrowings under the Credit Facility were $265.0 million and $162.0 million at December 31, 2018 and 2017, respectively.