Inventoried Costs (Details) - USD ($) $ in Millions	Jun. 28, 2015	Dec. 28, 2014
Inventory Disclosure [Abstract]
Raw materials	$ 29.8	$ 30.1
Work in process	21.4	13.3
Finished goods	3.2	2.8
Supplies and other	1.6	2.1
Subtotal inventoried costs	56.0	48.3
Less: Customer advances and progress payments	(6.5)	(0.9)
Total inventoried costs	$ 49.5	$ 47.4