SEGMENT AND GEOGRAPHIC INFORMATION, Revenue and Income (Loss) From Operations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Segment Reporting Information, Revenue for Reportable Segment	$ 272,116	$ 242,307
Segment Reporting Information, Income (Loss) from Operations for Reportable Segment	26,438	55,659
Affymetrix Core [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Revenue for Reportable Segment	235,105	242,307
Segment Reporting Information, Income (Loss) from Operations for Reportable Segment	35,230	55,659
eBioscience [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Revenue for Reportable Segment	37,011	0
Segment Reporting Information, Income (Loss) from Operations for Reportable Segment	$ (8,792)	$ 0