Inventoried Costs (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 30, 2012
Inventory Disclosure [Abstract]
Raw materials	$ 42.4	$ 48.4
Work in process	36.5	36.5
Finished goods	5.3	7.3
Supplies and other	1.8	2.2
Total inventoried costs	86.0	94.4
Less: customer advances and progress payments	(0.7)	(0.1)
Total inventoried costs	$ 85.3	$ 94.3