CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2024	Dec. 31, 2023	Dec. 25, 2022
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 16.3	$ 2.4	$ (33.2)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Change in unrealized cash flow hedge (net of taxes of $0.2 million, at December 29, 2024, and $0.2 million at December 31, 2023).	0.1	0.7	0.0
Change in cumulative translation adjustment	(2.2)	1.9	(2.3)
Postretirement benefit reserve adjustment net of tax	(0.1)	(0.1)	0.9
Total other comprehensive income (loss), net of tax	(2.2)	2.5	(1.4)
Comprehensive income (loss), net of tax	14.1	4.9	(34.6)
Less: Comprehensive income attributable to noncontrolling interest	0.0	11.3	3.7
Comprehensive income (loss) attributable to Kratos, net of tax	$ 14.1	$ (6.4)	$ (38.3)