Inventories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Net Components of Inventory
Raw materials	$ 371,481	$ 356,899
Work in process	863,478	786,664
Finished goods	304,111	306,765
Less: Progress billings	(332,701)	(304,395)
Less: Excess and obsolete reserve	(85,121)	(85,263)
Inventories, net	$ 1,121,248	$ 1,060,670