Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 27, 2022	Mar. 28, 2021
Disaggregation of Revenue [Line Items]
Total Revenues	$ 196.2	$ 194.2
Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	143.6	138.3
Kratos Government Solutions | U.S. Government
Disaggregation of Revenue [Line Items]
Total Revenues	89.5	92.6
Kratos Government Solutions | International
Disaggregation of Revenue [Line Items]
Total Revenues	34.7	31.7
Kratos Government Solutions | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total Revenues	19.4	14.0
Kratos Government Solutions | Fixed price
Disaggregation of Revenue [Line Items]
Total Revenues	101.3	99.5
Kratos Government Solutions | Cost plus fee
Disaggregation of Revenue [Line Items]
Total Revenues	32.3	28.6
Kratos Government Solutions | Time and materials
Disaggregation of Revenue [Line Items]
Total Revenues	10.0	10.2
Unmanned Systems
Disaggregation of Revenue [Line Items]
Total Revenues	52.6	55.9
Unmanned Systems | U.S. Government
Disaggregation of Revenue [Line Items]
Total Revenues	50.1	49.6
Unmanned Systems | International
Disaggregation of Revenue [Line Items]
Total Revenues	1.8	6.3
Unmanned Systems | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total Revenues	0.7	0.0
Unmanned Systems | Fixed price
Disaggregation of Revenue [Line Items]
Total Revenues	31.5	37.2
Unmanned Systems | Cost plus fee
Disaggregation of Revenue [Line Items]
Total Revenues	20.4	17.9
Unmanned Systems | Time and materials
Disaggregation of Revenue [Line Items]
Total Revenues	$ 0.7	$ 0.8