SEGMENT AND GEOGRAPHIC INFORMATION, Revenue and Loss From Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Segment Reporting Information, Revenue for Reportable Segment	$ 77,945	$ 65,247
Segment Reporting Information, Loss from Operations for Reportable Segment	(12,206)	(3,352)
Affymetrix Core [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Revenue for Reportable Segment	58,937	65,247
Segment Reporting Information, Loss from Operations for Reportable Segment	(7,841)	(3,352)
eBioscience [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Revenue for Reportable Segment	19,008	0
Segment Reporting Information, Loss from Operations for Reportable Segment	$ (4,365)	$ 0