Segment Information - Schedule of Segment Revenues, Depreciation and Amortization, and Operating (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 26, 2016	Jun. 28, 2015	Jun. 26, 2016	Jun. 28, 2015
Revenues:
Service revenues	$ 88.2	$ 88.8	$ 170.8	$ 176.1
Product sales	80.0	71.7	150.4	141.3
Total revenues	168.2	160.5	321.2	317.4
Depreciation & amortization:
Total depreciation and amortization			11.7	13.6
Operating income (loss) from continuing operations:
Total operating loss from continuing operations	0.0	(3.7)	(10.2)	(7.6)
Reportable Segments
Depreciation & amortization:
Total depreciation and amortization	5.6	6.7	11.7	13.6
Reportable Segments | Kratos Government Solutions
Revenues:
Service revenues	57.8	53.3	110.2	103.1
Product sales	62.2	53.8	118.4	111.0
Total revenues	120.0	107.1	228.6	214.1
Depreciation & amortization:
Total depreciation and amortization	3.6	5.0	7.7	10.1
Operating income (loss) from continuing operations:
Total operating loss from continuing operations	4.5	0.2	2.7	2.6
Reportable Segments | Public Safety & Security
Revenues:
Service revenues	30.4	35.5	60.6	73.0
Product sales	0.0	0.0	0.0	0.0
Total revenues	30.4	35.5	60.6	73.0
Depreciation & amortization:
Total depreciation and amortization	0.2	0.1	0.3	0.3
Operating income (loss) from continuing operations:
Total operating loss from continuing operations	0.2	0.6	(2.5)	0.6
Reportable Segments | Unmanned Systems
Revenues:
Service revenues	0.0	0.0	0.0	0.0
Product sales	17.8	17.9	32.0	30.3
Total revenues	17.8	17.9	32.0	30.3
Depreciation & amortization:
Total depreciation and amortization	1.8	1.6	3.7	3.2
Operating income (loss) from continuing operations:
Total operating loss from continuing operations	(3.0)	(2.5)	(7.2)	(6.7)
Unallocated corporate expense, net
Operating income (loss) from continuing operations:
Total operating loss from continuing operations	$ (1.7)	$ (2.0)	$ (3.2)	$ (4.1)