Costs And Estimated Earnings On Uncompleted Contracts (Summary Of Costs And Estimated Earnings On Uncompleted Contracts) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Costs And Estimated Earnings On Uncompleted Contracts [Abstract]
Costs incurred on uncompleted contracts	$ 34,577	$ 78,849
Estimated earnings	11,185	29,333
Billings to date	(36,027)	(95,055)
Costs and estimated earnings on uncompleted contracts	$ 9,735	$ 13,127