Organization and Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenues	$ 185.1	$ 184.1	$ 187.9	$ 160.4	$ 164.4	$ 159.4	$ 151.2	$ 143.0	$ 717.5	$ 618.0	$ 603.3
Kratos Government Solutions
Disaggregation of Revenue [Line Items]
Total revenues									556.1	485.1
Kratos Government Solutions | U.S. Government
Disaggregation of Revenue [Line Items]
Total revenues									368.6	333.5
Kratos Government Solutions | International
Disaggregation of Revenue [Line Items]
Total revenues									111.4	96.0
Kratos Government Solutions | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total revenues									76.1	55.6
Kratos Government Solutions | Fixed price
Disaggregation of Revenue [Line Items]
Total revenues									469.4	424.9
Kratos Government Solutions | Cost plus fee
Disaggregation of Revenue [Line Items]
Total revenues									54.3	32.6
Kratos Government Solutions | Time and materials
Disaggregation of Revenue [Line Items]
Total revenues									32.4	27.6
Unmanned Systems
Disaggregation of Revenue [Line Items]
Total revenues									161.4	132.9
Unmanned Systems | U.S. Government
Disaggregation of Revenue [Line Items]
Total revenues									138.8	113.5
Unmanned Systems | International
Disaggregation of Revenue [Line Items]
Total revenues									21.1	18.3
Unmanned Systems | U.S. Commercial and other customers
Disaggregation of Revenue [Line Items]
Total revenues									1.5	1.1
Unmanned Systems | Fixed price
Disaggregation of Revenue [Line Items]
Total revenues									126.2	104.8
Unmanned Systems | Cost plus fee
Disaggregation of Revenue [Line Items]
Total revenues									33.8	26.5
Unmanned Systems | Time and materials
Disaggregation of Revenue [Line Items]
Total revenues									$ 1.4	$ 1.6