Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Shares [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total stockholders' Equity of UCT [Member]	Noncontrolling Interests [Member]
Beginning balance at Dec. 25, 2020	$ 551.2	$ 0.1	$ 312.8	$ (3.3)	$ 217.9	$ 5.1	$ 532.6	$ 18.6
Beginning balance, Shares at Dec. 25, 2020		40,600,000		600,000
Issuance of common stock in public offering	192.8		192.8				192.8
Issuance of common stock in public offering, Shares		3,700,000
Issuance under employee stock plans	0.3		0.3				0.3
Issuance under employee stock plans, Shares		600,000
Employees’ taxes paid upon vesting of restricted stock units	(7.0)		(7.0)				(7.0)
Employees' taxes paid upon vesting of restricted stock units, Shares		(100,000)
Stock-based compensation expense	7.2		7.2				7.2
Noncontrolling interests from acquisition of Ham-let	1.2							1.2
Net income	43.6				42.1		42.1	1.5
Dividend payments to a joint venture shareholder	(0.1)							(0.1)
Other comprehensive gain (loss)	(0.5)					(0.5)	(0.5)
Ending balance at Jun. 25, 2021	788.7	$ 0.1	506.1	$ (3.3)	260.0	4.6	767.5	21.2
Ending balance, Shares at Jun. 25, 2021		44,800,000		600,000
Beginning balance at Mar. 26, 2021	576.6	$ 0.1	316.3	$ (3.3)	242.9	1.6	557.6	19.0
Beginning balance, Shares at Mar. 26, 2021		40,600,000		600,000
Issuance of common stock in public offering	192.8		192.8				192.8
Issuance of common stock in public offering, Shares		3,700,000
Issuance under employee stock plans	0.3		0.3				0.3
Issuance under employee stock plans, Shares		600,000
Employees’ taxes paid upon vesting of restricted stock units	(7.0)		(7.0)				(7.0)
Employees' taxes paid upon vesting of restricted stock units, Shares		(100,000)
Stock-based compensation expense	3.7		3.7				3.7
Noncontrolling interests from acquisition of Ham-let	1.2							1.2
Net income	18.0				17.1		17.1	0.9
Dividend payments to a joint venture shareholder	(0.1)							(0.1)
Other comprehensive gain (loss)	3.0					3.0	3.0
Ending balance at Jun. 25, 2021	788.7	$ 0.1	506.1	$ (3.3)	260.0	4.6	767.5	21.2
Ending balance, Shares at Jun. 25, 2021		44,800,000		600,000
Beginning balance at Dec. 31, 2021	892.7	$ 0.1	514.9	$ (3.3)	337.4	(0.2)	848.9	43.8
Beginning balance, Shares at Dec. 31, 2021		44,900,000		600,000
Issuance under employee stock plans	0.7		0.7				0.7
Issuance under employee stock plans, Shares		600,000
Employees’ taxes paid upon vesting of restricted stock units	(3.8)		(3.8)				(3.8)
Employees' taxes paid upon vesting of restricted stock units, Shares		(100,000)
Stock-based compensation expense	10.1		10.1				10.1
Net income	9.1				2.8		2.8	6.3
Dividend payments to a joint venture shareholder	(0.2)							(0.2)
Other comprehensive gain (loss)	(13.1)					(13.1)	(13.1)
Ending balance at Jul. 01, 2022	895.5	$ 0.1	521.9	$ (3.3)	340.2	(13.3)	845.6	49.9
Ending balance, Shares at Jul. 01, 2022		45,400,000		600,000
Beginning balance at Apr. 01, 2022	926.3	$ 0.1	520.5	$ (3.3)	365.3	(3.0)	879.6	46.7
Beginning balance, Shares at Apr. 01, 2022		45,000,000.0		600,000
Issuance under employee stock plans	0.7		0.7				0.7
Issuance under employee stock plans, Shares		500,000
Employees’ taxes paid upon vesting of restricted stock units	(3.8)		(3.8)				(3.8)
Employees' taxes paid upon vesting of restricted stock units, Shares		(100,000)
Stock-based compensation expense	4.5		4.5				4.5
Net income	(21.7)				(25.1)		(25.1)	3.4
Dividend payments to a joint venture shareholder	(0.2)							(0.2)
Other comprehensive gain (loss)	(10.3)					(10.3)	(10.3)
Ending balance at Jul. 01, 2022	$ 895.5	$ 0.1	$ 521.9	$ (3.3)	$ 340.2	$ (13.3)	$ 845.6	$ 49.9
Ending balance, Shares at Jul. 01, 2022		45,400,000		600,000