Segment Information - Schedule of Segment Revenues, Depreciation and Amortization, and Operating (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Total revenues	$ 168.9	$ 160.4
Depreciation & amortization:
Total depreciation and amortization	6.3	5.1
Operating income from continuing operations:
Total operating income from continuing operations	4.7	8.2
Service revenues
Segment Reporting Information [Line Items]
Total revenues	63.6	62.6
Product sales
Segment Reporting Information [Line Items]
Total revenues	105.3	97.8
Kratos Government Solutions
Segment Reporting Information [Line Items]
Total revenues	126.9	125.5
Depreciation & amortization:
Total depreciation and amortization	4.7	3.9
Kratos Government Solutions | Service revenues
Segment Reporting Information [Line Items]
Total revenues	63.6	62.6
Kratos Government Solutions | Product sales
Segment Reporting Information [Line Items]
Total revenues	63.3	62.9
Unmanned Systems
Segment Reporting Information [Line Items]
Total revenues	42.0	34.9
Depreciation & amortization:
Total depreciation and amortization	1.6	1.2
Reportable Segments | Kratos Government Solutions
Operating income from continuing operations:
Total operating income from continuing operations	9.3	11.4
Reportable Segments | Unmanned Systems
Operating income from continuing operations:
Total operating income from continuing operations	0.5	0.6
Corporate activities
Operating income from continuing operations:
Total operating income from continuing operations	$ (5.1)	$ (3.8)