Organization and Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2024	Dec. 31, 2023	Dec. 25, 2022
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,136.3	$ 1,037.1	$ 898.3
Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total revenues	865.8	824.9	676.6
Kratos Government Solutions | U.S. Government
Disaggregation of Revenue [Line Items]
Total revenues	528.0	512.5	420.4
Kratos Government Solutions | International
Disaggregation of Revenue [Line Items]
Total revenues	195.4	192.8	157.5
Kratos Government Solutions | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total revenues	142.4	119.6	98.7
Kratos Government Solutions | Fixed price
Disaggregation of Revenue [Line Items]
Total revenues	571.5	566.3	476.1
Kratos Government Solutions | Cost plus fee
Disaggregation of Revenue [Line Items]
Total revenues	233.9	209.5	158.4
Kratos Government Solutions | Time and materials
Disaggregation of Revenue [Line Items]
Total revenues	60.4	49.1	42.1
Unmanned Systems
Disaggregation of Revenue [Line Items]
Total revenues	270.5	212.2	221.7
Unmanned Systems | U.S. Government
Disaggregation of Revenue [Line Items]
Total revenues	234.0	200.2	203.3
Unmanned Systems | International
Disaggregation of Revenue [Line Items]
Total revenues	31.3	9.2	15.6
Unmanned Systems | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total revenues	5.2	2.8	2.8
Unmanned Systems | Fixed price
Disaggregation of Revenue [Line Items]
Total revenues	216.4	160.9	156.6
Unmanned Systems | Cost plus fee
Disaggregation of Revenue [Line Items]
Total revenues	48.1	41.9	59.1
Unmanned Systems | Time and materials
Disaggregation of Revenue [Line Items]
Total revenues	$ 6.0	$ 9.4	$ 6.0