Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014	Dec. 28, 2014
Revenues:
Service revenues	$ 88.8	$ 101.8	$ 176.1	$ 202.4
Product sales	71.7	102.4	141.3	175.6
Total revenues	160.5	204.2	317.4	378.0
Depreciation & amortization:
Total depreciation and amortization			13.6	15.8
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	(3.7)	2.3	(7.6)	2.7
Assets	1,102.6		1,102.6		$ 1,138.8
Discontinued operations, Assets	188.0		188.0		190.8
Reportable Segments
Revenues:
Total revenues	160.5	204.2	317.4	378.0
Depreciation & amortization:
Total depreciation and amortization	6.7	8.0	13.6	15.8
Unallocated corporate expense, net
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	(2.0)	(3.6)	(4.1)	(5.4)
Assets	50.0		50.0		62.8
Kratos Government Solutions | Reportable Segments
Revenues:
Service revenues	53.3	51.1	103.1	102.9
Product sales	53.8	71.6	111.0	125.1
Total revenues	107.1	122.7	214.1	228.0
Depreciation & amortization:
Total depreciation and amortization	5.0	5.9	10.1	11.7
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	0.2	4.8	2.6	8.0
Assets	598.3		598.3		618.9
Public Safety & Security | Reportable Segments
Revenues:
Service revenues	35.5	50.7	73.0	99.5
Product sales	0.0	13.0	0.0	13.0
Total revenues	35.5	63.7	73.0	112.5
Depreciation & amortization:
Total depreciation and amortization	0.1	0.5	0.3	1.0
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	0.6	2.9	0.6	3.7
Assets	100.9		100.9		100.2
Unmanned Systems | Reportable Segments
Revenues:
Service revenues	0.0	0.0	0.0	0.0
Product sales	17.9	17.8	30.3	37.5
Total revenues	17.9	17.8	30.3	37.5
Depreciation & amortization:
Total depreciation and amortization	1.6	1.6	3.2	3.1
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	(2.5)	$ (1.8)	(6.7)	$ (3.6)
Assets	$ 165.4		$ 165.4		$ 166.1