Document And Entity Information	9 Months Ended
	Oct. 02, 2011	Oct. 31, 2011
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Oct. 02, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Entity Registrant Name	ULTRATECH INC
Entity Central Index Key	0000909791
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		11,111,111