Business Segment Information (Intercompany Segment Gross Profit (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Information [Line Items]
Gross profit (loss) with other operating segments of same entity	$ (93)	$ 19,112	$ 13,454
Contracting Services [Member]
Segment Reporting Information [Line Items]
Gross profit (loss) with other operating segments of same entity	104	15,655	13,205
Production Facilities [Member]
Segment Reporting Information [Line Items]
Gross profit (loss) with other operating segments of same entity	(197)	3,457	(116)
Shelf Contracting [Member]
Segment Reporting Information [Line Items]
Gross profit (loss) with other operating segments of same entity			$ 365