CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 25, 2022	Dec. 26, 2021
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 2.4	$ (33.2)	$ (1.6)
Other comprehensive loss:
Change in unrealized cash flow hedge (net of taxes of $0.2 million, at December 31, 2023).	0.7	0.0	0.0
Change in cumulative translation adjustment	1.9	(2.3)	(0.8)
Postretirement benefit reserve adjustment net of tax income (expense)	(0.1)	0.9	0.0
Other comprehensive income (loss), net of tax	2.5	(1.4)	(0.8)
Comprehensive income (loss)	4.9	(34.6)	(2.4)
Less: Comprehensive income attributable to noncontrolling interest	11.3	3.7	0.4
Comprehensive loss attributable to Kratos	$ (6.4)	$ (38.3)	$ (2.8)