Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 27, 2025	Jun. 28, 2024	Jun. 27, 2025	Jun. 28, 2024
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (160.5)	$ 21.5	$ (162.9)	$ 14.2
Other comprehensive income (loss):
Change in cumulative translation adjustment, net of tax	9.5	(2.0)	10.0	(6.3)
Total other comprehensive income (loss)	9.5	(2.0)	10.0	(6.3)
Comprehensive income (loss)	(151.0)	19.5	(152.9)	7.9
Comprehensive income, attributable to noncontrolling interests	5.7	1.3	8.3	1.2
Comprehensive income (loss) attributable to UCT	$ (156.7)	$ 18.2	$ (161.2)	$ 6.7