Condensed Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues:
Contract operations	$ 52,678	$ 33,144		$ 102,022	$ 65,040
Parts and service	588	166		1,446	874
Total revenues	53,266	33,310		103,468	65,914
Costs and expenses:
Cost of operations, exclusive of depreciation and amortization	17,997	10,131		35,714	20,551
Selling, general, and administrative	10,186	5,548		18,655	10,443
Depreciation and amortization	17,044	12,173		33,264	23,851
Loss (gain) on sale of assets	(2,520)	130		(2,291)	105
Total costs and expenses	42,707	27,982		85,342	54,950
Operating income	10,559	5,328		18,126	10,964
Other income (expense):
Interest expense	(3,043)	(2,871)		(6,592)	(5,934)
Other	2	2		2	6
Total other expense	(3,041)	(2,869)		(6,590)	(5,928)
Net income before income tax expense	7,518	2,459		11,536	5,036
Income tax expense		58		103	114
Net income	7,518	2,401		11,433	4,922
Earnings allocated to general partner	188	48	5	274	88
Limited partners' interest in net income:
Limited partners' interest in net income			530
Net income subsequent to initial public offering	7,518	2,401	4,387	11,433
Net income per unit:
Distributions paid per limited partner unit in respective periods (in dollars per unit)	$ 0.49	$ 0.348		$ 0.97	$ 0.348
Common units
Limited partners' interest in net income:
Limited partners' interest in net income	5,332	1,227		7,769	2,242
Weighted average units outstanding:
Basic (in units)	27,290,699	15,196,880		25,557,737	15,130,872
Diluted (in units)	27,327,545	15,241,866		25,626,850	15,155,834
Net income per unit:
Basic (in dollars per unit)	$ 0.20	$ 0.08		$ 0.30	$ 0.15
Diluted (in dollars per unit)	$ 0.20	$ 0.08		$ 0.30	$ 0.15
Subordinated units
Limited partners' interest in net income:
Limited partners' interest in net income	$ 1,998	$ 1,126		$ 3,390	$ 2,057
Weighted average units outstanding:
Basic and diluted (in units)	14,048,588	14,048,588		14,048,588	14,048,588
Net income per unit:
Basic and diluted (in dollars per unit)	$ 0.14	$ 0.08		$ 0.24	$ 0.15