Inventory (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary Of Inventories [Abstract]
Raw materials	$ 250.3	$ 236.9
Work-in-process	2,207.4	1,800.0
Finished goods	35.9	40.8
Net Inventory Raw Materials Finished Goods And Work In Process	2,493.6	2,077.7
Capitalized pre-production	524.6	553.2	541.8
Provision for Loss on Contracts	607.4	227.9
Inventory	$ 2,410.8	$ 2,630.9