Consolidated Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statement of Cash Flows [Abstract]
Accounts receivable	$ 4,734	$ (186,384)	$ (62,991)
Costs and estimated earnings in excess of billings	(178,774)	(153,153)	(107,983)
Other current assets	(38,616)	(17,450)	25,250
Accounts payable	139,290	33,667	59,169
Billings in excess of costs and estimated earnings	(30,985)	51,711	(36,835)
Accrued expenses	(24,426)	2,801	(6,509)
Decrease in cash due to changes in operating assets and liabilities	(128,777)	(268,808)	(129,899)
Interest	45,055	45,236	41,207
Income taxes	$ 35,299	75,494	28,898
Property and equipment acquired through financing arrangements not included in financing activities		$ 816	$ 16,689