Investments in Unconsolidated Affiliates - Condensed Statements Of Income (Details) (Medusa Spar LLC Investment [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Medusa Spar LLC Investment [Member]
Condensed Statements of Operations
Revenue	$ 4,023	$ 3,354
Depreciation	(2,369)	(2,369)
General and administrative	(19)	(18)
Net Income	$ 1,635	$ 967

The amount of net income (loss) reported by an equity method investment of the entity.

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+ Details