Subsequent Events	6 Months Ended
Jun. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	16. SUBSEQUENT EVENTS On June 15, 2016, certain wholly-owned subsidiaries of the Partnership entered into an agreement with Gateway Resources U.S.A., Inc. to sell substantially all of the Partnerships’ operated oil and gas wells, leases and other associated assets and interests in Oklahoma and Kansas (other than those arising under or related to a concession agreement with the Osage Nation) for cash consideration of $7,120, subject to adjustment for title and environmental defects, effective as of August 1, 2016 (the “Effective Time”). In addition, Gateway Resources U.S.A., Inc. agreed to assume all obligations relating to the assets arising after the Effective Time and all plugging and abandonment costs relating to the assets arising prior to the Effective Time. The Partnership closed the sale of this transaction on July 15, 2016. There is no remaining book value of the assets to be sold. Therefore, the Partnership does not expect to record a loss on the transaction. On July 5, 2016, the Partnership entered into an agreement with SN and SN Midstream, LLC, a wholly-owned subsidiary of SN, to purchase 50% of the issued and outstanding membership interests in Carnero Gathering, LLC for total consideration of approximately $37.0 million, plus the assumption of approximately $7.4 million of remaining capital contribution commitments, of which $1.7 million was paid in July 2016. In addition, the Partnership is required to pay an earnout based on gas received at the delivery points from SN Catarina, LLC, a wholly-owned subsidiary of SN, and other producers. The membership interests acquired constitute 50% of the outstanding membership interests in Carnero Gathering, LLC, with the other 50% of the membership interests being owned by TPL SouthTex Processing Company LP. Carnero Gathering, LLC is developing and constructing a gas gathering pipeline from an interconnection in Webb County, Texas to interconnection(s) with a gas processing facility being developed and constructed by Carnero Processing, LLC. On July 5, 2016, the Partnership and certain of its subsidiaries entered into that certain Fourth Amendment to Third Amended and Restated Credit Agreement dated as of March 31, 2015 among the Partnership, the guarantors party thereto, each of the lenders party thereto, and Royal Bank of Canada, as administrative agent and collateral agent. Pursuant to the Amendment, the following amendments to the Credit Agreement were made: pricing table was increased; certain covenants were amended to permit the Partnership to own equity interests in joint ventures (including Carnero Gathering, LLC); the Midstream Adjusted EBITDA definition was amended to include in the calculation thereof any distributions received in cash from a joint venture so long as such amount does not exceed 20% of the Midstream Adjusted EBITDA and so long as a “Trigger Event” has not occurred. A “Trigger Event” is defined to be: (i) the ownership and control of less than all of the equity interests initially owned in a joint venture, (ii) the incurrence by the joint venture of any debt other than certain permitted debt, (iii) the disposition by the joint venture of a material portion of its assets, (iv) the incurrence by the joint venture of any liens other than certain permitted liens, (v) the modification of any gathering, compressing, processing, transportation, services or other commercial agreement to which the primary revenues of the joint venture are attributable if the effect of such modification is to reduce in any material respect any minimum committed volumes or minimum committed service level thereunder, or (vi) the joint venture voluntarily filing bankruptcy; a new repayment event was added with respect to any cash or cash equivalents held by the Partnership in excess of $10,000,000 (other than cash set aside to pay distributions in the next 90 days); the title requirement with respect to proved reserves was increased from 80% to 90%; the Partnership is required to pledge its equity interests in any joint venture as collateral under the Credit Agreement; the Partnership, and any of its designees to the board of a joint venture, are restricted from voting on any matter set forth in clauses (ii) through (v) of the definition of “Trigger Event” without the consent of the majority lenders; 10% availability on the entire credit facility (rather than just the RBL component) is required before the Partnership can make distributions; and certain technical revisions were made. On August 10, 2016, the board of directors of the general partner of the Partnership declared cash distributions of $0.4183 per common unit and $0.450 per Class B preferred unit for the second quarter of 2016. The distributions are payable on August 31, 2016 to unitholders of record on August 22, 2016.

16. SUBSEQUENT EVENTS

On June 15, 2016, certain wholly-owned subsidiaries of the Partnership entered into an agreement with Gateway Resources U.S.A., Inc. to sell substantially all of the Partnerships’ operated oil and gas wells, leases and other associated assets and interests in Oklahoma and Kansas (other than those arising under or related to a concession agreement with the Osage Nation) for cash consideration of $7,120, subject to adjustment for title and environmental defects, effective as of August 1, 2016 (the “Effective Time”). In addition, Gateway Resources U.S.A., Inc. agreed to assume all obligations relating to the assets arising after the Effective Time and all plugging and abandonment costs relating to the assets arising prior to the Effective Time. The Partnership closed the sale of this transaction on July 15, 2016. There is no remaining book value of the assets to be sold. Therefore, the Partnership does not expect to record a loss on the transaction.

On July 5, 2016, the Partnership entered into an agreement with SN and SN Midstream, LLC, a wholly-owned subsidiary of SN, to purchase 50% of the issued and outstanding membership interests in Carnero Gathering, LLC for total consideration of approximately $37.0 million, plus the assumption of approximately $7.4 million of remaining capital contribution commitments, of which $1.7 million was paid in July 2016. In addition, the Partnership is required to pay an earnout based on gas received at the delivery points from SN Catarina, LLC, a wholly-owned subsidiary of SN, and other producers. The membership interests acquired constitute 50% of the outstanding membership interests in Carnero Gathering, LLC, with the other 50% of the membership interests being owned by TPL SouthTex Processing Company LP. Carnero Gathering, LLC is developing and constructing a gas gathering pipeline from an interconnection in Webb County, Texas to interconnection(s) with a gas processing facility being developed and constructed by Carnero Processing, LLC.

On July 5, 2016, the Partnership and certain of its subsidiaries entered into that certain Fourth Amendment to Third Amended and Restated Credit Agreement dated as of March 31, 2015 among the Partnership, the guarantors party thereto, each of the lenders party thereto, and Royal Bank of Canada, as administrative agent and collateral agent. Pursuant to the Amendment, the following amendments to the Credit Agreement were made: pricing table was increased; certain covenants were amended to permit the Partnership to own equity interests in joint ventures (including Carnero Gathering, LLC); the Midstream Adjusted EBITDA definition was amended to include in the calculation thereof any distributions received in cash from a joint venture so long as such amount does not exceed 20% of the Midstream Adjusted EBITDA and so long as a “Trigger Event” has not occurred. A “Trigger Event” is defined to be: (i) the ownership and control of less than all of the equity interests initially owned in a joint venture, (ii) the incurrence by the joint venture of any debt other than certain permitted debt, (iii) the disposition by the joint venture of a material portion of its assets, (iv) the incurrence by the joint venture of any liens other than certain permitted liens, (v) the modification of any gathering, compressing, processing, transportation, services or other commercial agreement to which the primary revenues of the joint venture are attributable if the effect of such modification is to reduce in any material respect any minimum committed volumes or minimum committed service level thereunder, or (vi) the joint venture voluntarily filing bankruptcy; a new repayment event was added with respect to any cash or cash equivalents held by the Partnership in excess of $10,000,000 (other than cash set aside to pay distributions in the next 90 days); the title requirement with respect to proved reserves was increased from 80% to 90%; the Partnership is required to pledge its equity interests in any joint venture as collateral under the Credit Agreement; the Partnership, and any of its designees to the board of a joint venture, are restricted from voting on any matter set forth in clauses (ii) through (v) of the definition of “Trigger Event” without the consent of the majority lenders; 10% availability on the entire credit facility (rather than just the RBL component) is required before the Partnership can make distributions; and certain technical revisions were made.

On August 10, 2016, the board of directors of the general partner of the Partnership declared cash distributions of $0.4183 per common unit and $0.450 per Class B preferred unit for the second quarter of 2016. The distributions are payable on August 31, 2016 to unitholders of record on August 22, 2016.