Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014 Segment	Sep. 29, 2013
Segment Reporting Information [Line Items]
Number of principal reportable business segments			2
Revenues:
Service revenues	$ 97.1	$ 108.8	$ 299.5	$ 335.0
Product sales	120.0	117.6	347.0	379.9
Total revenues	217.1	226.4	646.5	714.9
Depreciation & amortization:
Total depreciation and amortization	9.9	12.9	29.2	40.7
Operating income:
Total operating income	1.2	6.1	9.2	26.4
Unallocated corporate expense, net
Operating income:
Total operating income	(2.9)	(2.1)	(8.3)	(3.1)
Kratos Government Solutions
Segment Reporting Information [Line Items]
Number of business segments			5
Revenues:
Service revenues	54.3	57.0	157.2	180.9
Product sales	120.0	117.6	334.0	379.9
Total revenues	174.3	174.6	491.2	560.8
Depreciation & amortization:
Total depreciation and amortization	9.4	12.1	27.7	38.0
Operating income:
Total operating income	8.2	6.4	17.6	23.8
Public Safety & Security
Revenues:
Service revenues	42.8	51.8	142.3	154.1
Product sales	0	0	13.0	0
Total revenues	42.8	51.8	155.3	154.1
Depreciation & amortization:
Total depreciation and amortization	0.5	0.8	1.5	2.7
Operating income:
Total operating income	$ (4.1)	$ 1.8	$ (0.1)	$ 5.7