Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Total Stockholders’ Equity of UCT	Common Stock	Additional Paid-in Capital	Treasury shares	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Common stock, shares, beginning balance (in shares) at Dec. 27, 2024			45.1
Treasury stock, shares, beginning balance (in shares) at Dec. 27, 2024					1.5
Beginning balance at Dec. 27, 2024	$ 935.8	$ 873.6	$ 0.1	$ 558.4	$ (45.0)	$ 370.4	$ (10.3)	$ 62.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	2.9	2.9		2.9
Net income (loss)	(2.5)	(5.0)				(5.0)		2.5
Other comprehensive income (loss)	0.6	0.5					0.5	0.1
Ending balance at Mar. 28, 2025	$ 936.8	872.0	$ 0.1	561.3	$ (45.0)	365.4	(9.8)	64.8
Common stock, shares, ending balance (in shares) at Mar. 28, 2025			45.1
Treasury stock, shares, ending balance (in shares) at Mar. 28, 2025					1.5
Common stock, shares, beginning balance (in shares) at Dec. 26, 2025	45.5		45.5
Treasury stock, shares, beginning balance (in shares) at Dec. 26, 2025	1.7				1.7
Beginning balance at Dec. 26, 2025	$ 784.1	711.0	$ 0.1	578.7	$ (48.4)	189.2	(8.6)	73.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capped call transactions	(25.1)	(25.1)		(25.1)
Repurchase of common stock (in shares)			(0.7)		0.7
Repurchase of common stock		(40.3)			$ (40.3)
Stock-based compensation expense	3.2	3.2		3.2
Net income (loss)	(15.0)	(17.9)				(17.9)		2.9
Other comprehensive income (loss)	(4.8)	(3.0)					(3.0)	(1.8)
Ending balance at Mar. 27, 2026	$ 702.1	$ 627.9	$ 0.1	$ 556.8	$ (88.7)	$ 171.3	$ (11.6)	$ 74.2
Common stock, shares, ending balance (in shares) at Mar. 27, 2026	44.8		44.8
Treasury stock, shares, ending balance (in shares) at Mar. 27, 2026	2.4				2.4