Goodwill and Intangible Assets - Goodwill (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended		9 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended
	Sep. 30, 2012	Dec. 25, 2011	Sep. 30, 2012 Public Safety and Security	Dec. 25, 2011 Public Safety and Security	Sep. 30, 2012 Kratos Government Solutions	Dec. 25, 2011 Kratos Government Solutions	Jun. 30, 2012 Discontinued operations Integral Systems, Inc.	Jun. 24, 2012 Discontinued operations Integral Systems, Inc.
Goodwill [Line Items]
Goodwill impairment charge associated with discontinued operations							$ 1.5	$ 1.5
Goodwill, Access Of Fair Value Over Carrying Value, Percentage					7.40%
Goodwill [Roll Forward]
Balance as of December 25, 2011		572.0		33.0		539.0
Retrospective adjustments	(0.4)		0		(0.4)
Balance as of December 25, 2011 after retrospective adjusments	571.6		33.0		538.6
Additions due to business combinations	106.9		3.8		103.1
Balance as of June 24, 2012	678.5		36.8		641.7
Accumulated impairment losses	$ 165.4	$ 165.4	$ 18.3	$ 18.3	$ 147.1	$ 147.1