Contracts in Progress (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Contractors [Abstract]
Costs incurred on uncompleted contracts	$ 372,750	$ 343,524
Estimated earnings	71,076	64,358
Costs incurred and estimated earnings on uncompleted contracts	443,826	407,882
Less: Billings to date	(434,603)	(405,006)
Costs and estimated earnings in excess of billings on uncompleted contracts, net	9,223	2,876
Costs and estimated earnings in excess of billings on uncompleted contracts	19,892	19,245
Billings in excess of costs and estimated earnings on uncompleted contracts	$ (10,669)	$ (16,369)