Inventories (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of Inventory
Raw materials	$ 352,928,000	$ 356,899,000
Work in process	687,343,000	786,664,000
Finished goods	265,439,000	306,765,000
Less: Progress billings	(230,058,000)	(304,395,000)
Less: Excess and obsolete reserve	(80,088,000)	(85,263,000)
Inventories, net	995,564,000	1,060,670,000
Expenses due to excess and obsolete inventory	$ 19,200,000	$ 24,400,000	$ 18,200,000