Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Third-party customers	$ 25,859	$ 22,933	$ 75,420	$ 68,136
Related parties	1,431	3,739	4,382	10,847
Revenues	27,290	26,672	79,802	78,983
Expenses:
Operating expenses	8,848	8,192	26,595	25,107
Selling, general and administrative	4,999	3,141	10,950	10,168
Selling, general and administrative – affiliate	1,368	1,342	3,941	3,965
Depreciation	4,623	3,972	13,565	11,345
Amortization	3,547	3,672	10,808	11,042
(Gain) Loss on revaluation of contingent consideration, net	534	545	1,465	(303)
Total expenses	23,919	20,864	67,324	61,324
Operating income (loss)	3,371	5,808	12,478	17,659
Other income (expense):
Equity earnings from unconsolidated affiliate	2,431	2,512	7,243	7,439
Gain (Loss) on disposal of property and equipment	(1,484)		(1,484)	0
Other income	60	1	60	2
Interest expense	(3,132)	(2,481)	(8,656)	(7,234)
Total other income (expense)	(2,125)	32	(2,837)	207
Income before income taxes	1,246	5,840	9,641	17,866
Income taxes	55	49	86	101
Net income	1,191	5,791	9,555	17,765
Net income attributable to non-controlling interests	(1,047)	(1,659)	(3,720)	(5,553)
Net income attributable to partners' capital	144	4,132	5,835	12,212
Other comprehensive (loss) income	475	831	1,156	(84)
Comprehensive income (loss) attributable to partners’ capital	$ 619	$ 4,963	$ 6,991	$ 12,128
Common Units [Member]
Earnings (loss) per limited partner unit:
Earnings per limited partner unit, basic and diluted	$ 0.00	$ 0.20	$ 0.27	$ 0.59
Subordinated Units [Member]
Earnings (loss) per limited partner unit:
Earnings per limited partner unit, basic and diluted		$ 0.20		$ 0.59