Acquisitions - Purchase Price Allocation (Details) (USD $) In Millions, unless otherwise specified	Dec. 30, 2011 Critical Infrastructure Business	Nov. 15, 2011 SecureInfo Corporation	Jul. 27, 2011 Integral Systems, Inc.	Mar. 25, 2011 Herley Industries, Inc.
Business Acquisition, Purchase Price Allocation [Abstract]
Cash		$ 1.4	$ 6.8	$ 21.8
Accounts receivable	23.4		68.4	39.1
Inventoried costs			15.8	42.8
Deferred tax assets			36.4	17.3
Other assets	0.5	3.0	3.5	7.2
Property and equipment		0.1	12.9	34.2
Intangible assets	2.0	4.5	32.0	37.0
Goodwill	3.8	12.2	187.8	146.4
Total assets	29.7	21.2	363.6	345.8
Current liabilities	(9.7)	(0.9)	(84.5)	(40.8)
Deferred tax liabilities			(19.5)	(16.8)
Debt				(9.5)
Long-term liabilities			(18.5)	(6.2)
Net assets acquired	$ 20.0	$ 20.3	$ 241.1	$ 272.5