Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (353)	$ (7,100)
Adjustments to reconcile net loss to cash provided by operating activities:
Depreciation, depletion and amortization	6,443	14,294
Amortization of debt issuance costs	265	259
Asset impairments		4,688
Accretion expense	249	498
Distributions from equity investments	13,101	3,684
Equity earnings in affiliate	(7,383)	(1,524)
Gain from disposition of property and equipment	(2,388)
Net (gains) losses on commodity derivative contracts	5,653	(9,268)
Net cash settlements received (paid) on commodity derivative contracts	(706)	3,378
Unit-based compensation	2,785	2,019
Loss on earnout derivative	1,524
Amortization of intangible assets	6,730	6,824
Costs for plug and abandon activities		(45)
Changes in Operating Assets and Liabilities:
Accounts receivable	185	(369)
Accounts receivable - related entities	6,541	(125)
Prepaid expenses	83	(567)
Other assets	43	(146)
Accounts payable and accrued liabilities	7,687	7,309
Accounts payable and accrued liabilities- related entities	(3,376)	(222)
Royalties payable	(1)	(171)
Net cash provided by operating activities	37,082	23,416
Cash flows from investing activities:
Final settlement of oil and natural gas properties acquisition		1,468
Development of oil and natural gas properties	(205)	(210)
Proceeds from sale of assets	5,896
Construction of gathering and transportation assets	(1,700)	(15,240)
Purchases of and contributions to equity affiliates	(2,713)	(8,286)
Net cash provided by (used in) investing activities	1,278	(22,268)
Cash flows from financing activities:
Payments for offering costs	(50)	(293)
Proceeds from issuance of debt		25,000
Repayment of debt	(5,000)
Issuance of common units		1,290
Distributions to common unitholders	(13,614)	(12,044)
Class B preferred unit cash distributions	(17,500)	(14,000)
Debt issuance costs	(33)	(27)
Net cash provided by (used in) financing activities	(36,197)	(74)
Net decrease in cash and cash equivalents	2,163	1,074
Cash and cash equivalents, beginning of period	321	957
Cash and cash equivalents, end of period	2,484	2,031
Supplemental disclosures of cash flow information:
Change in accrued capital expenditures	341	8,601
Asset retirement obligation	288	195
Earnout derivative		221
Cash paid during the period for interest	$ 4,788	$ 3,548