Significant Customers (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Revenue, Major Customer [Line Items]
Sales to the U.S. Government - amount	$ 868.0	$ 950.6	$ 969.2
Kratos Government Solutions
Revenue, Major Customer [Line Items]
Sales to the U.S. Government - amount	590.1	619.3	690.9
U.S. Government | Kratos Government Solutions
Revenue, Major Customer [Line Items]
Sales to the U.S. Government - amount	$ 514.6	$ 606.7	$ 627.8
Sales to the U.S. Government - percentage of total revenue	59.00%	64.00%	65.00%