Equity Investments - Distributions from Equity Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule of Equity Method Investments [Line Items]
Distributions from equity method investments	$ 1,200	$ 1,400
Deepwater Gateway, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Distributions from equity method investments	1,200	1,000
Independence Hub, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Distributions from equity method investments	$ 0	$ 400