CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues:
Revenue - third parties	$ 167,785	$ 145,581	$ 332,033	$ 266,542
Revenue - affiliates	16	113	63	198
Total revenue	167,801	145,694	332,096	266,740
Costs and expenses:
Cost of sales (excluding depreciation and amortization expense) - affiliates	65,942	59,835	131,110	113,038
Depreciation and amortization	39,487	31,708	75,592	59,629
Long-lived asset impairment	1,826	1,991	5,310	4,477
Restructuring charges		198		577
Selling, general and administrative - affiliates	20,721	19,047	41,890	38,423
Interest expense	19,082	14,756	36,914	24,445
Other (income) expense, net	(1,512)	(134)	(1,703)	737
Total costs and expenses	145,546	127,401	289,113	241,326
Income before income taxes	22,255	18,293	42,983	25,414
Provision for (benefit from) income taxes	(72)	541	571	723
Net income	22,327	17,752	42,412	24,691
General partner interest in net income	4,814	3,088	9,023	5,694
Common units interest in net income	$ 17,513	$ 14,664	$ 33,389	$ 18,997
Weighted average common units outstanding used in income per common unit:
Basic (in units)	58,987	55,592	57,342	52,528
Diluted (in units)	58,987	55,594	57,342	52,529
Income per common unit:
Basic (in dollars per unit)	$ 0.30	$ 0.26	$ 0.58	$ 0.36
Diluted (in dollars per unit)	0.30	0.26	0.58	0.36
Distributions declared and paid per limited partner unit in respective periods (in dollars per unit)	$ 0.5625	$ 0.5375	$ 1.1200	$ 1.0700