Organization and Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 25, 2022	Dec. 26, 2021
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,037.1	$ 898.3	$ 811.5
Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total revenues	824.9	676.6
Kratos Government Solutions | U.S. Government
Disaggregation of Revenue [Line Items]
Total revenues	512.5	420.4
Kratos Government Solutions | International
Disaggregation of Revenue [Line Items]
Total revenues	192.8	157.5
Kratos Government Solutions | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total revenues	119.6	98.7
Kratos Government Solutions | Fixed price
Disaggregation of Revenue [Line Items]
Total revenues	566.3	476.1
Kratos Government Solutions | Cost plus fee
Disaggregation of Revenue [Line Items]
Total revenues	209.5	158.4
Kratos Government Solutions | Time and materials
Disaggregation of Revenue [Line Items]
Total revenues	49.1	42.1
Unmanned Systems
Disaggregation of Revenue [Line Items]
Total revenues	212.2	221.7
Unmanned Systems | U.S. Government
Disaggregation of Revenue [Line Items]
Total revenues	200.2	203.3
Unmanned Systems | International
Disaggregation of Revenue [Line Items]
Total revenues	9.2	15.6
Unmanned Systems | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total revenues	2.8	2.8
Unmanned Systems | Fixed price
Disaggregation of Revenue [Line Items]
Total revenues	160.9	156.6
Unmanned Systems | Cost plus fee
Disaggregation of Revenue [Line Items]
Total revenues	41.9	59.1
Unmanned Systems | Time and materials
Disaggregation of Revenue [Line Items]
Total revenues	$ 9.4	$ 6.0