Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 28, 2025	Sep. 29, 2024	Sep. 28, 2025	Sep. 29, 2024
Disaggregation of Revenue [Line Items]
Total Revenues	$ 347.6	$ 275.9	$ 1,001.7	$ 853.2
Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	260.3	211.7	778.1	643.8
Kratos Government Solutions | U.S. Government
Disaggregation of Revenue [Line Items]
Total Revenues	164.7	128.4	500.8	392.7
Kratos Government Solutions | International
Disaggregation of Revenue [Line Items]
Total Revenues	55.8	52.1	163.3	144.1
Kratos Government Solutions | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total Revenues	39.8	31.2	114.0	107.0
Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	87.3	64.2	223.6	209.4
Unmanned Systems | U.S. Government
Disaggregation of Revenue [Line Items]
Total Revenues	66.4	55.5	184.5	177.5
Unmanned Systems | International
Disaggregation of Revenue [Line Items]
Total Revenues	3.9	6.5	18.7	27.7
Unmanned Systems | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total Revenues	17.0	2.2	20.4	4.2
Fixed price | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	171.5	140.2	508.3	425.6
Fixed price | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	71.6	51.0	183.4	166.6
Cost plus fee | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	77.2	57.3	230.0	174.1
Cost plus fee | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	15.1	11.5	38.0	37.6
Time and materials | Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	11.6	14.2	39.8	44.1
Time and materials | Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	$ 0.6	$ 1.7	$ 2.2	$ 5.2