CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
CURRENT ASSETS
Cash and cash equivalents	$ 3,906	$ 5,414
Accounts receivable	95,958	113,148
Commodity derivative assets	24,441	37,970
Prepaid expenses and other current assets	1,977	1,001
TOTAL CURRENT ASSETS	126,282	157,533
PROPERTY AND EQUIPMENT
Oil and natural gas properties, at cost, using the successful efforts method of accounting, includes unproved properties of $1,089,576 and $1,063,883 at June 30, 2019 and December 31, 2018, respectively	3,501,789	3,441,188
Accumulated depreciation, depletion, amortization, and impairment	(1,921,674)	(1,865,692)
Oil and natural gas properties, net	1,580,115	1,575,496
Other property and equipment, net of accumulated depreciation of $11,267 and $11,048 at June 30, 2019 and December 31, 2018, respectively	2,319	385
NET PROPERTY AND EQUIPMENT	1,582,434	1,575,881
DEFERRED CHARGES AND OTHER LONG-TERM ASSETS	15,839	16,710
TOTAL ASSETS	1,724,555	1,750,124
CURRENT LIABILITIES
Accounts payable	5,911	4,149
Accrued liabilities	39,105	60,089
Other current liabilities	957	528
TOTAL CURRENT LIABILITIES	45,973	64,766
LONG–TERM LIABILITIES
Credit facility	436,000	410,000
Accrued incentive compensation	1,395	1,813
Commodity derivative liabilities	45	0
Asset retirement obligations	15,377	14,948
Other long-term liabilities	81,750	55,973
TOTAL LIABILITIES	580,540	547,500
COMMITMENTS AND CONTINGENCIES (Note 8)
EQUITY
Partners' equity – general partner interest	0	0
TOTAL EQUITY	845,654	904,263
TOTAL LIABILITIES, MEZZANINE EQUITY, AND EQUITY	1,724,555	1,750,124
Series B Cumulative Convertible Preferred Units
MEZZANINE EQUITY
Partners' equity – convertible preferred units	298,361	298,361
Common Units
EQUITY
Partners' equity - units	845,654	714,823
Subordinated Units
EQUITY
Partners' equity - units	$ 0	$ 189,440