Document And Entity Information	3 Months Ended
	Apr. 01, 2017 shares
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Apr. 01, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1
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	27,236,174