Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Customer relationships	$ 13,736		$ 13,736		$ 13,699
Pipeline rights-of-way	(7,632)		(7,632)		(7,184)
Intangible assets, net	6,104		6,104		6,515
Amortization of Intangible Assets	300	$ 300	600	$ 600
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Remainder of 2017	677		677
2017	1,286		1,286
2018	1,252		1,252
2019	958		958
2020	805		805
2021	691		$ 691
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		7,172
Pipeline rights-of-way	(4,499)		(4,499)		(4,234)
Intangible assets, net	2,673		$ 2,673		2,938
Finite-Lived Intangible Asset, Useful Life			5 years
Use Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Customer relationships	6,564		$ 6,564		6,527
Pipeline rights-of-way	(3,133)		(3,133)		(2,950)
Intangible assets, net	$ 3,431		$ 3,431		$ 3,577
Finite-Lived Intangible Asset, Useful Life			6 years 3 days