Segment Information - Schedule of Segment Revenues, Depreciation and Amortization, and Operating (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2017	Mar. 27, 2016
Revenues:
Service revenues	$ 85.0	$ 82.6
Product sales	82.8	70.4
Total revenues	167.8	153.0
Depreciation & amortization:
Total depreciation and amortization	5.6	6.1
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	1.7	(10.2)
Reportable Segments
Depreciation & amortization:
Total depreciation and amortization	5.6	6.1
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	4.4	(8.7)
Reportable Segments | Kratos Government Solutions
Revenues:
Service revenues	48.2	52.4
Product sales	67.2	56.2
Total revenues	115.4	108.6
Depreciation & amortization:
Total depreciation and amortization	3.7	4.1
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	9.6	(1.8)
Reportable Segments | Public Safety & Security
Revenues:
Service revenues	36.8	30.2
Product sales	0.0	0.0
Total revenues	36.8	30.2
Depreciation & amortization:
Total depreciation and amortization	0.1	0.1
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	(0.2)	(2.7)
Reportable Segments | Unmanned Systems
Revenues:
Service revenues	0.0	0.0
Product sales	15.6	14.2
Total revenues	15.6	14.2
Depreciation & amortization:
Total depreciation and amortization	1.8	1.9
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	(5.0)	(4.2)
Unallocated corporate expense, net
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	$ (2.7)	$ (1.5)