Accounts Receivable And Contracts In Progress (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Retainage	$ 17,392	$ 27,203
Accounts receivable, gross	115,374	135,101
Allowance for doubtful accounts	(454)	(754)
Total accounts receivable—net	114,920	134,347
Current portion of accounts receivable—net	110,940	130,777
Long-term accounts receivable and retainage	3,980	3,570
Completed Contracts [Member]
Accounts Notes And Loans Receivable [Line Items]
contracts	23,742	37,111
Contracts In Progress [Member]
Accounts Notes And Loans Receivable [Line Items]
contracts	$ 74,240	$ 70,787