Segment Information - Schedule of Segment Revenues, Depreciation and Amortization, and Operating (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2023	Mar. 27, 2022
Segment Reporting Information [Line Items]
Total revenues	$ 231.8	$ 196.2
Depreciation and amortization:
Total depreciation and amortization	7.9	7.0
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	0.5	(1.2)
Corporate activities
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	(6.6)	(7.3)
Kratos Government Solutions
Segment Reporting Information [Line Items]
Total revenues	183.8	143.6
Depreciation and amortization:
Total depreciation and amortization	5.9	5.1
Kratos Government Solutions | Reportable Segments
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	7.7	5.6
Unmanned Systems
Segment Reporting Information [Line Items]
Total revenues	48.0	52.6
Depreciation and amortization:
Total depreciation and amortization	2.0	1.9
Unmanned Systems | Reportable Segments
Operating income (loss) from continuing operations:
Total operating income (loss) from continuing operations	(0.6)	0.5
Service revenues
Segment Reporting Information [Line Items]
Total revenues	91.6	67.9
Service revenues | Kratos Government Solutions
Segment Reporting Information [Line Items]
Total revenues	90.2	66.8
Service revenues | Unmanned Systems
Segment Reporting Information [Line Items]
Total revenues	1.4	1.1
Product sales
Segment Reporting Information [Line Items]
Total revenues	140.2	128.3
Product sales | Kratos Government Solutions
Segment Reporting Information [Line Items]
Total revenues	93.6	76.8
Product sales | Unmanned Systems
Segment Reporting Information [Line Items]
Total revenues	$ 46.6	$ 51.5