Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended
	Mar. 28, 2025	Mar. 29, 2024
Statement of Comprehensive Income [Abstract]
Net loss	$ (2.5)	$ (7.2)
Other comprehensive income (loss):
Change in cumulative translation adjustment, net of tax	0.6	(4.4)
Total other comprehensive income (loss)	0.6	(4.4)
Comprehensive loss	(1.9)	(11.6)
Comprehensive income (loss), attributable to noncontrolling interests	2.6	(0.1)
Comprehensive loss attributable to UCT	$ (4.5)	$ (11.5)