SEGMENT AND GEOGRAPHIC INFORMATION - Revenue and Income (Loss) From Operations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 business_unit segment	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Number of reportable segments	2
Number of business units	4
Revenue	$ 349,019	$ 330,399	$ 295,623
Income (loss) from operations	2,123	(12,552)	(39,091)
Affymetrix Core [Member]
Segment Reporting Information [Line Items]
Revenue	256,525	241,450	245,105
Income (loss) from operations	2,917	(1,085)	(35,374)
eBioscience [Member]
Segment Reporting Information [Line Items]
Revenue	92,494	88,949	50,518
Income (loss) from operations	$ (794)	$ (11,467)	$ (3,717)