Accounts Receivable And Contracts In Progress (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Receivables [Abstract]
Completed contracts	$ 12,379	$ 37,111
Contracts in progress	87,965	70,787
Retainage	20,340	27,203
Accounts receivable, gross	120,684	135,101
Allowance for doubtful accounts	(469)	(754)
Total accounts receivable—net	120,215	134,347
Current portion of accounts receivable—net	115,753	130,777
Long-term accounts receivable and retainage	$ 4,462	$ 3,570