Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Customer relationships	$ 13,768		$ 13,699
Pipeline rights-of-way	(7,467)		(7,184)
Intangible assets, net	6,301		6,515
Amortization of Intangible Assets	300	$ 300
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Remainder of 2017	820
2017	1,094
2018	1,094
2019	799
2020	646
2021	$ 533
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	35 years
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Customer relationships	$ 7,172		7,172
Pipeline rights-of-way	(4,367)		(4,234)
Intangible assets, net	$ 2,805		2,938
Finite-Lived Intangible Asset, Useful Life	5 years 3 months 25 days
Use Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Customer relationships	$ 6,596		6,527
Pipeline rights-of-way	(3,100)		(2,950)
Intangible assets, net	$ 3,496		$ 3,577
Finite-Lived Intangible Asset, Useful Life	5 years 3 months 25 days