Net Income Per Share - Basic and Diluted Net Income (loss) Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 30, 2022	Dec. 31, 2021	Dec. 31, 2021	Dec. 25, 2020	Dec. 25, 2020
Numerator:
Net income (loss) attributable to UCT	$ 40.4	$ 119.5	$ 119.5	$ 77.6	$ 77.6
Shares used in computation — basic:
Weighted average common shares outstanding	45.2	43.5	43.5	40.2	40.2
Shares used in computation — diluted:
Weighted average common shares outstanding	45.2	43.5	43.5	40.2	40.2
Dilutive effect of common shares outstanding subject to repurchase	0.5		0.9		0.9
Shares used in computing diluted net income per share	45.7	44.4	44.4	41.1	41.1
Net income (loss) per share attributable to UCT — basic	$ 0.89	$ 2.75	$ 2.75	$ 1.93	$ 1.93
Net income (loss) per share attributable to UCT — diluted	$ 0.88	$ 2.69	$ 2.69	$ 1.89	$ 1.89