Supplemental Balance Sheet Information - Uncompleted Contracts (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Supplemental Balance Sheet Data [Abstract]
Costs incurred on uncompleted contracts	$ 818,008	$ 795,139
Estimated earnings to date	159,321	158,982
Subtotal	977,329	954,121
Less – billings to date	(975,663)	(903,098)
Total	1,666	51,023
Costs and estimated earnings in excess of billings	89,141	94,045
Billings in excess of costs and estimated earnings	(87,475)	(43,022)
Total	$ 1,666	$ 51,023