Business Segment Information (Intercompany Segment Gross Profit (Losses)) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Gross profit (loss) with other operating segments of same entity	$ 19	$ 6,114	$ (71)	$ 18,436
Contracting Services [Member]
Gross profit (loss) with other operating segments of same entity	63	3,701	39	15,143
Production Facilities [Member]
Gross profit (loss) with other operating segments of same entity	$ (44)	$ 2,413	$ (110)	$ 3,293