Business Segment Information (Intercompany Segment Gross Profit (Losses)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Gross profit (loss) with other operating segments of same entity	$ 3,020	$ (90)
Contracting Services [Member]
Gross profit (loss) with other operating segments of same entity	3,064	(24)
Production Facilities [Member]
Gross profit (loss) with other operating segments of same entity	$ (44)	$ (66)