Organization and Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jun. 25, 2017	Mar. 26, 2017	Dec. 30, 2018	Dec. 31, 2017	Dec. 25, 2016
Disaggregation of Revenue [Line Items]
Total revenues	$ 164.4	$ 159.4	$ 151.2	$ 143.0	$ 166.3	$ 157.1	$ 147.9	$ 132.0	$ 618.0	$ 603.3	$ 541.9
Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total revenues									485.1
Kratos Government Solutions | U.S. Government
Disaggregation of Revenue [Line Items]
Total revenues									333.5
Kratos Government Solutions | International
Disaggregation of Revenue [Line Items]
Total revenues									96.0
Kratos Government Solutions | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total revenues									55.6
Kratos Government Solutions | Fixed price
Disaggregation of Revenue [Line Items]
Total revenues									424.9
Kratos Government Solutions | Cost plus fee
Disaggregation of Revenue [Line Items]
Total revenues									32.6
Kratos Government Solutions | Time and materials
Disaggregation of Revenue [Line Items]
Total revenues									27.6
Unmanned Systems
Disaggregation of Revenue [Line Items]
Total revenues									132.9
Unmanned Systems | U.S. Government
Disaggregation of Revenue [Line Items]
Total revenues									113.5
Unmanned Systems | International
Disaggregation of Revenue [Line Items]
Total revenues									18.3
Unmanned Systems | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total revenues									1.1
Unmanned Systems | Fixed price
Disaggregation of Revenue [Line Items]
Total revenues									104.8
Unmanned Systems | Cost plus fee
Disaggregation of Revenue [Line Items]
Total revenues									26.5
Unmanned Systems | Time and materials
Disaggregation of Revenue [Line Items]
Total revenues									$ 1.6