Inventoried Costs (Details) (USD $) In Millions, unless otherwise specified	Jun. 24, 2012	Dec. 25, 2011
Inventory Disclosure [Abstract]
Raw materials	$ 45.8	$ 43.3
Work in process	30.8	25.7
Finished goods	9.2	6.9
Supplies and other	0.9	4.0
Total inventoried costs	86.7	79.9
Less customer advances and progress payments	(0.3)	(3.3)
Total inventoried costs	$ 86.4	$ 76.6