ACQUISITIONS - ADDITIONAL INFORMATION (Details) T in Thousands, $ in Thousands				1 Months Ended	4 Months Ended	8 Months Ended	12 Months Ended
		Jul. 25, 2014 USD ($) T	May. 14, 2013 USD ($) shares	Jun. 30, 2014 USD ($)	May. 13, 2013 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Business Acquisition [Line Items]
Goodwill							$ 29,264	$ 29,264
Total revenues	[1]						711,639	1,111,254	$ 873,255
Net income (loss)					$ 13,124	$ 22,046	(9,411)	89,079	35,170
Gain (loss) on settlement of pre-existing agreements							$ 0	$ (689)	0
Direct Fuels
Business Acquisition [Line Items]
Total purchase price			$ 98,277
Goodwill			29,264
Cash deposit			$ 22,900
Common units issues, shares | shares			3,180,612
Common units issued, value			$ 53,700
Long-term debt assumed			21,700
Less dividend payable			11,500
Intangible assets			$ 45,080
Transaction costs						1,500			$ 1,500
Total revenues						218,200
Net income (loss)						$ (1,500)
Midwest Frac and Sands LLC
Business Acquisition [Line Items]
Total purchase price		$ 22,390
Cash deposit		11,000		$ 11,000
Intangible assets		100
Transaction costs		100
Agreed cash purchase price		24,000
Liabilities incurred related to acquisition		$ 13,000
Estimated production capacity per year related to acquisition (in tons) | T		850
Gain (loss) on settlement of pre-existing agreements		$ (689)
Customer relationships | Direct Fuels
Business Acquisition [Line Items]
Estimated useful life of intangible assets			15 years
Non-compete agreement | Direct Fuels
Business Acquisition [Line Items]
Estimated useful life of intangible assets			4 years
Minimum | Midwest Frac and Sands LLC
Business Acquisition [Line Items]
Liabilities incurred, estimated payment per year		$ 2,000
Payment period of entire acquisition obligation		7 years
Minimum | Supply and Transportation Contracts | Direct Fuels
Business Acquisition [Line Items]
Estimated useful life of intangible assets			3 months
Maximum | Midwest Frac and Sands LLC
Business Acquisition [Line Items]
Payment period of entire acquisition obligation		8 years
Maximum | Supply and Transportation Contracts | Direct Fuels
Business Acquisition [Line Items]
Estimated useful life of intangible assets			54 months

[1] Fuel revenues and cost of goods sold include excise taxes and similar taxes $50,939 $50,116 $47,007.