Condensed Consolidated Statements of Comprehensive Income (loss) - USD ($) $ in Millions	3 Months Ended
	Apr. 01, 2022	Mar. 26, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 30.8	$ 25.6
Other comprehensive gain (loss):
Change in cumulative translation adjustment	(3.1)	(2.8)
Change in fair value of derivatives	0.3	(0.7)
Total other comprehensive gain (loss)	(2.8)	(3.5)
Other comprehensive income, attributable to noncontrolling interests	2.9	0.6
Comprehensive income attributable to UCT	$ 25.1	$ 21.5