Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Customer relationships	$ 14,078		$ 13,965
Pipeline rights-of-way	(6,512)		(6,208)
Intangible assets, net	7,566		7,757
Amortization of Intangible Assets	300	$ 300
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Remainder of 2016	901
2017	1,112
2018	1,112
2019	1,112
2020	818
2021	$ 665
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year	1 year
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	35 years	15 years
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Customer relationships	$ 7,551		7,551
Pipeline rights-of-way	(4,060)		(3,921)
Intangible assets, net	$ 3,491		3,630
Finite-Lived Intangible Asset, Useful Life	6 years 3 months 10 days
Use Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Customer relationships	$ 6,527		6,414
Pipeline rights-of-way	(2,452)		(2,287)
Intangible assets, net	$ 4,075		$ 4,127
Finite-Lived Intangible Asset, Useful Life	5 years 6 months