Business Segment Information (Intercompany Segment Gross Profit (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Gross profit (loss) with other operating segments of same entity	$ 7,878	$ (93)	$ 19,112
Contracting Services [Member]
Segment Reporting Information [Line Items]
Gross profit (loss) with other operating segments of same entity	8,053	104	15,655
Production Facilities [Member]
Segment Reporting Information [Line Items]
Gross profit (loss) with other operating segments of same entity	$ (175)	$ (197)	$ 3,457