Equity Investments (Distributions From Equity Investments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Schedule of Equity Method Investments [Line Items]
Distributions from equity investments	$ 3,200	$ 1,850	$ 5,860	$ 8,200
Deepwater Gateway, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Distributions from equity investments	2,000	1,250	3,500	3,400
Independence Hub, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Distributions from equity investments	$ 1,200	$ 600	$ 2,360	$ 4,800