CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
CURRENT ASSETS
Cash and cash equivalents	$ 5,642	$ 9,772
Accounts receivable	80,695	68,181
Commodity derivative assets	94	0
Prepaid expenses and other current assets	1,212	1,036
TOTAL CURRENT ASSETS	87,643	78,989
PROPERTY AND EQUIPMENT
Oil and natural gas properties, at cost, using the successful efforts method of accounting, includes unproved properties of $988,720 and $605,736 at December 31, 2017 and 2016, respectively	3,247,613	2,697,073
Accumulated depreciation, depletion, amortization, and impairment	(1,766,842)	(1,652,930)
Oil and natural gas properties, net	1,480,771	1,044,143
Other property and equipment, net of accumulated depreciation of $14,433 and $14,327 at December 31, 2017 and 2016, respectively	559	528
NET PROPERTY AND EQUIPMENT	1,481,330	1,044,671
DEFERRED CHARGES AND OTHER LONG-TERM ASSETS	7,478	5,167
TOTAL ASSETS	1,576,451	1,128,827
CURRENT LIABILITIES
Accounts payable	2,464	4,142
Accrued liabilities	52,631	50,952
Commodity derivative liabilities	4,222	16,237
Other current liabilities	417	0
TOTAL CURRENT LIABILITIES	59,734	71,331
LONG-TERM LIABILITIES
Credit facility	388,000	316,000
Accrued incentive compensation	3,648	1,485
Commodity derivative liabilities	1,263	482
Deferred revenue	0	518
Asset retirement obligations	14,092	13,350
Other long-term liabilities	19,171	0
TOTAL LIABILITIES	485,908	403,166
COMMITMENTS AND CONTINGENCIES (Note 11)
MEZZANINE EQUITY
Partners' equity — Series A redeemable preferred units, 26 and 53 units outstanding at December 31, 2017 and 2016, respectively	322,422	54,015
EQUITY
Partners' equity — general partner interest	0	0
Noncontrolling interests	867	1,021
TOTAL EQUITY	768,121	671,646
TOTAL LIABILITIES, MEZZANINE EQUITY, AND EQUITY	1,576,451	1,128,827
Series A Redeemable Preferred Units [Member]
MEZZANINE EQUITY
Partners' equity — Series A redeemable preferred units, 26 and 53 units outstanding at December 31, 2017 and 2016, respectively	27,028	54,015
Series B Cumulative Convertible Preferred Units
MEZZANINE EQUITY
Partners' equity — Series A redeemable preferred units, 26 and 53 units outstanding at December 31, 2017 and 2016, respectively	295,394	0
Common Units
EQUITY
Partners' equity - units	603,116	489,023
Subordinated Units
EQUITY
Partners' equity - units	$ 164,138	$ 181,602

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.