Inventory (Details) - USD ($)	3 Months Ended
	Apr. 02, 2020	Dec. 31, 2019
Summary Of Inventories [Abstract]
Raw materials	$ 321,000,000.0	$ 253,100,000
Work-in-process	803,100,000	822,800,000
Finished goods	16,800,000	14,500,000
Product inventory	1,140,900,000	1,090,400,000
Capitalized pre-production	27,800,000	28,400,000
Total inventory, net	1,168,700,000	1,118,800,000
Inventory Valuation Reserves	42,200,000	39,000,000.0
Costs Incurred in Anticipation of Contracts	158,200,000	$ 157,200,000
Cost, Overhead	73.4
Abnormal Costs- COVID19 production suspension	$ 25.4