Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 25, 2023	Jun. 30, 2024	Jun. 25, 2023
Disaggregation of Revenue [Line Items]
Total Revenues	$ 300.1	$ 256.9	$ 577.3	$ 488.7
Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	214.3	204.8	432.1	388.6
Kratos Government Solutions | U.S. Government
Disaggregation of Revenue [Line Items]
Total Revenues	129.2	129.5	264.3	244.0
Kratos Government Solutions | International
Disaggregation of Revenue [Line Items]
Total Revenues	41.3	47.9	92.0	92.9
Kratos Government Solutions | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total Revenues	43.8	27.4	75.8	51.7
Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	85.8	52.1	145.2	100.1
Unmanned Systems | U.S. Government
Disaggregation of Revenue [Line Items]
Total Revenues	66.2	49.1	122.0	94.9
Unmanned Systems | International
Disaggregation of Revenue [Line Items]
Total Revenues	18.8	2.4	21.2	4.3
Unmanned Systems | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total Revenues	0.8	0.6	2.0	0.9
Fixed price | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	139.7	132.5	285.4	259.5
Fixed price | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	71.7	39.0	115.6	75.9
Cost plus fee | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	58.2	59.9	116.8	105.6
Cost plus fee | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	12.6	10.5	26.1	18.6
Time and materials | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	16.4	12.4	29.9	23.5
Time and materials | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	$ 1.5	$ 2.6	$ 3.5	$ 5.6