Document and Entity Information (USD $)	3 Months Ended
	Mar. 31, 2013	Apr. 25, 2013	Dec. 31, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	AFFYMETRIX INC
Entity Central Index Key	0000913077
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 327,619,125
Entity Common Stock, Shares Outstanding		71,098,356
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2013