CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 25, 2022	Dec. 26, 2021	Dec. 27, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (33.2)	$ (1.6)	$ 79.4
Other comprehensive income (loss):
Change in cumulative translation adjustment	(2.3)	(0.8)	2.0
Postretirement benefit reserve adjustment net of tax expense (income)	0.9	0.0	(0.2)
Other comprehensive income (loss), net of tax	(1.4)	(0.8)	1.8
Comprehensive income (loss)	(34.6)	(2.4)	81.2
Less: Comprehensive income (loss) attributable to noncontrolling interest	3.7	0.4	(0.2)
Comprehensive income (loss) attributable to Kratos	$ (38.3)	$ (2.8)	$ 81.4