Segment Information - Segment Revenues, Depreciation and Amortization, and Operating (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 26, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 277.2	$ 231.8
Depreciation and amortization:
Total depreciation and amortization	9.3	7.9
Operating income (loss):
Total operating income	7.0	0.5
Kratos Government Solutions
Segment Reporting Information [Line Items]
Total revenues	217.8	183.8
Unmanned Systems
Segment Reporting Information [Line Items]
Total revenues	59.4	48.0
Operating segments | Kratos Government Solutions
Segment Reporting Information [Line Items]
Total revenues	217.8	183.8
Depreciation and amortization:
Total depreciation and amortization	6.1	5.9
Operating income (loss):
Total operating income	16.6	7.7
Operating segments | Unmanned Systems
Segment Reporting Information [Line Items]
Total revenues	59.4	48.0
Depreciation and amortization:
Total depreciation and amortization	3.2	2.0
Operating income (loss):
Total operating income	(0.4)	(0.6)
Corporate activities
Operating income (loss):
Total operating income	(9.2)	(6.6)
Service revenues
Segment Reporting Information [Line Items]
Total revenues	106.5	91.6
Service revenues | Operating segments | Kratos Government Solutions
Segment Reporting Information [Line Items]
Total revenues	104.6	90.2
Service revenues | Operating segments | Unmanned Systems
Segment Reporting Information [Line Items]
Total revenues	1.9	1.4
Product sales
Segment Reporting Information [Line Items]
Total revenues	170.7	140.2
Product sales | Operating segments | Kratos Government Solutions
Segment Reporting Information [Line Items]
Total revenues	113.2	93.6
Product sales | Operating segments | Unmanned Systems
Segment Reporting Information [Line Items]
Total revenues	$ 57.5	$ 46.6