Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ 1,442	$ (7,659)
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation, depletion and amortization	3,263	8,769
Amortization of debt issuance costs	131	128
Asset impairments		4,688
Accretion expense	126	258
Distributions (return on investment) from equity investments	6,992	2,010
Equity earnings in affiliate	(4,272)	(482)
Net (gains) losses on commodity derivative contracts	1,937	(6,055)
Net cash settlements received (paid) on commodity derivative contracts	(189)	1,513
Unit-based compensation	738	540
Loss on earnout derivative	270
Amortization of intangible assets	3,365	3,412
Changes in Operating Assets and Liabilities:
Accounts receivable	102	43
Accounts receivable - related entities	7,105	2,951
Prepaid expenses	66	(20)
Other assets	22	83
Accounts payable and accrued liabilities	5,591	(3,092)
Accounts payable and accrued liabilities- related entities	(3,570)	6,226
Royalties payable	(3)	248
Net cash provided by operating activities	23,116	13,561
Cash flows from investing activities:
Final settlement of oil and natural gas properties acquisition		1,468
Development of oil and natural gas properties	(3)	(143)
Proceeds from sale of assets	350
Construction of gathering and transportation assets	(1,160)	(5,786)
Purchases of and contributions to equity affiliates	(263)	(2,122)
Net cash used in investing activities	(1,076)	(6,583)
Cash flows from financing activities:
Payments for offering costs	(50)	(120)
Proceeds from issuance of debt		7,500
Repayment of debt	(5,000)
Distributions to common unitholders	(6,746)	(5,796)
Class B preferred unit cash distributions	(8,750)	(7,000)
Debt issuance costs	(11)	(26)
Net cash provided by (used in) financing activities	(20,557)	(5,442)
Net decrease in cash and cash equivalents	1,483	1,536
Cash and cash equivalents, beginning of period	321	957
Cash and cash equivalents, end of period	1,804	2,493
Supplemental disclosures of cash flow information:
Change in accrued capital expenditures	641	7,158
Asset retirement obligation	288	195
Earnout liability		221
Cash paid during the period for interest	$ 2,300	$ 1,473