Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flow from operating activities:
Net income	$ 21,908	$ 10,744	$ 1,275
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	15,704	11,680	7,261
Amortization	14,714	10,819	5,427
Long-lived asset impairment	0	0	6,114
Equity earnings from unconsolidated affiliate, net of distributions	(262)	(544)	(68)
Amortization of deferred financing costs	1,551	1,031	496
Unit-based compensation	4,112	5,474	3,138
Loss on revaluation of contingent consideration, net	1,043	0	0
Changes in operating assets and liabilities
Trade accounts receivable	376	(4,887)	658
Due from related parties	211	(631)	(179)
Inventories	84	(33)	17
Other current assets	(898)	64	(449)
Accounts payable	(1,923)	1,248	(3,151)
Accrued expenses	(366)	3,712	(10)
Due to general partner	1,444	229	281
Other liabilities	(2,063)	(1,474)	2,756
Net cash provided by operating activities	55,635	37,432	23,566
Cash flows from investing activities:
Capital expenditures	(24,348)	(13,150)	(6,611)
Investment in unconsolidated affiliate	0	(361)	(1,197)
Net cash paid for acquisitions	(8,000)	(260,332)	0
Net cash used in investing activities	(32,348)	(273,843)	(7,808)
Cash flows from financing activities:
Distributions	(33,931)	(27,272)	(18,179)
Deferred financing costs	(586)	(3,239)	(518)
Repayments to credit facility	(7,313)	0	(25,000)
Proceeds from credit facility	30,250	115,000	30,500
Proceeds from equity offerings, net	0	72,026	0
Equity contribution from non-controlling interests	0	86,960	0
Payments of earn-out liability	(1,373)	(870)	0
Distributions paid to non-controlling interests	(10,600)	(6,000)	0
Distribution equivalent rights paid on unissued units	(1,020)	(923)	(416)
Net cash (used in) provided by financing activities	(24,573)	235,682	(13,613)
Net increase (decrease) in cash and cash equivalents	(1,286)	(729)	2,145
Cash and cash equivalents, beginning of period	5,870	6,599	4,454
Cash and cash equivalents, end of period	4,584	5,870	6,599
Supplemental disclosure of cash flow information:
Cash paid for interest, net of capitalized interest	8,229	6,112	3,398
Cash paid for income taxes	124	119	58
Non-cash investing and financing activities:
Liabilities assumed in acquisition	0	4,523	0
Business acquisition purchase consideration - earn-out liability	0	19,700	0
(Decrease) Increase in earn-out liability in accounts payable and accrued expenses	500	0	0
(Decrease) Increase in purchases of property plant and equipment in accounts payable and accrued expenses	(1,641)	2,712	1,173
Common Stock [Member]
Non-cash investing and financing activities:
Issuance of common units in acquisition	$ 0	$ 30,200	$ 0