Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2023	Jun. 26, 2022	Jun. 25, 2023	Jun. 26, 2022
Disaggregation of Revenue [Line Items]
Total Revenues	$ 256.9	$ 224.2	$ 488.7	$ 420.4
Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	204.8	167.8	388.6	311.4
Kratos Government Solutions | U.S. Government
Disaggregation of Revenue [Line Items]
Total Revenues	129.5	104.2	244.0	193.7
Kratos Government Solutions | International
Disaggregation of Revenue [Line Items]
Total Revenues	47.9	36.1	92.9	70.8
Kratos Government Solutions | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total Revenues	27.4	27.5	51.7	46.9
Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	52.1	56.4	100.1	109.0
Unmanned Systems | U.S. Government
Disaggregation of Revenue [Line Items]
Total Revenues	49.1	51.9	94.9	102.0
Unmanned Systems | International
Disaggregation of Revenue [Line Items]
Total Revenues	2.4	3.6	4.3	5.4
Unmanned Systems | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total Revenues	0.6	0.9	0.9	1.6
Fixed price | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	132.5	119.9	259.5	221.2
Fixed price | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	39.0	40.7	75.9	72.2
Cost plus fee | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	59.9	37.1	105.6	69.4
Cost plus fee | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	10.5	15.3	18.6	35.7
Time and materials | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	12.4	10.8	23.5	20.8
Time and materials | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	$ 2.6	$ 0.4	$ 5.6	$ 1.1