Document and Entity Information (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 28, 2012	Feb. 28, 2013	Jun. 29, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	ULTRA CLEAN HOLDINGS INC
Entity Central Index Key	0001275014
Document Type	10-K/A
Document Period End Date	Dec. 28, 2012
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-28
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		28,155,408
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 150.5
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No