Consolidated Statements of Operations Statement - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues [Abstract]
Total revenues	$ 2,222,718	$ 2,599,867	$ 3,501,888
Cost of Goods Sold [Abstract]
Cost of products sold, affiliate	468,935	573,264	871,751
Cost of products sold, third-party	1,447,178	1,734,873	2,373,168
Operating Costs and Expenses [Abstract]
Operating and maintenance expenses	174,936	175,767	168,432
Selling, general and administrative expenses	23,386	25,063	23,839
Loss (gain) and impairments on disposal of assets, net	(1,054)	(278)	157
Depreciation and amortization	39,242	35,384	28,934
Total operating costs and expenses	2,152,623	2,544,073	3,466,281
Operating income	70,095	55,794	35,607
Other income (expense):
Interest income	0	0	4
Interest and debt expense	(25,972)	(23,107)	(2,374)
Other income (expense), net	(70)	66	130
Net income before income taxes	44,053	32,753	33,367
Provision for income taxes	(706)	(47)	(459)
Net income	(43,347)	(32,706)	(32,908)
Less net loss attributable to General Partner	(23,309)	(29,867)	(20,084)
Net income attributable to limited partners	$ 66,656	$ 62,573	$ 52,992
Earnings Per Share [Abstract]
Cash distributions declared per common unit	$ 1.6300	$ 1.4275	$ 1.1632
Sales Based Revenues [Member]
Revenues [Abstract]
Revenues: Affiliate	$ 479,033	$ 582,888	$ 835,203
Revenues: Third-party	1,517,650	1,810,773	2,487,595
Fee Based Revenues [Member]
Revenues [Abstract]
Revenues: Affiliate	223,124	203,435	176,372
Revenues: Third-party	$ 2,911	$ 2,771	$ 2,718
Common Units [Member]
Earnings Per Share [Abstract]
Earnings Per Share, Basic	$ 1.16	$ 1.31	$ 1.16
Earnings Per Share, Diluted	$ 1.16	$ 1.30	$ 1.15
Weighted Average Number of Shares Outstanding, Basic	29,979	24,084	23,059
Weighted Average Number of Shares Outstanding, Diluted	29,994	24,099	23,107
Subordinated Units [Member]
Earnings Per Share [Abstract]
Earnings Per Share, Basic and Diluted	$ 1.21	$ 1.30	$ 1.15
Weighted Average Number of Shares Outstanding, Basic and Diluted	22,811	22,811	22,811