Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 321	$ 957
Accounts receivable	495	1,212
Accounts receivable - related entities	13,099	5,987
Prepaid expenses	2,670	2,041
Fair value of derivative instruments	942	4,568
Total current assets	17,527	14,765
Oil and natural gas properties and related equipment
Oil and natural gas properties, equipment and facilities (successful efforts method)	170,750	758,913
Gathering and transportation assets	184,969	152,209
Material and supplies		1,056
Less: accumulated depreciation, depletion, amortization and impairment	(142,574)	(689,358)
Oil and natural gas properties and equipment, net	213,145	222,820
Other assets
Intangible assets, net	172,166	185,766
Fair value of derivative instruments	1,318	3,964
Equity investments	123,715	111,614
Other non-current assets	552	776
Total assets	528,423	539,705
Current liabilities
Accounts payable and accrued liabilities	1,782	951
Accounts payable and accrued liabilities - related entities	10,353	7,046
Royalties payable	371	706
Fair value of derivative instruments	756	740
Other liabilities	151
Total current liabilities	13,413	9,443
Other liabilities
Asset retirement obligation	6,074	13,579
Long-term debt, net of debt issuance costs	187,808	151,322
Fair value of derivative instruments	273	1,356
Other liabilities	6,251	4,270
Total other liabilities	200,406	170,527
Total liabilities	213,819	179,970
Commitments and contingencies (See Note 12)
Mezzanine equity
Class B preferred units, 31,000,887 and 29,296,441 units issued and outstanding as of December 31, 2017 and 2016, respectively	343,912	342,991
Partners' capital (deficit)
Common units, 14,965,134 and 13,447,749 units issued and outstanding as of December 31, 2017 and 2016, respectively	(29,308)	16,744
Total partners' capital (deficit)	(29,308)	16,744
Total liabilities and partners' capital	$ 528,423	$ 539,705