INVENTORIES, Fair Value Step-Up in Basis (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013
INVENTORIES [Abstract]
Inventory, Step Up Adjustment	$ 14,749
Cost of goods sold inventory step-up, amortization	$ 4,589

The amount of expense recognized in the current period that reflects the allocation of the costs of fair value step-up in inventory over the expected benefit period of such assets. This element applies only to the fair value step-up in inventory used in the production of goods.

No definition available.

Name:	affx_CostOfGoodsSoldInventoryStep-UpAmortization
Namespace Prefix:	affx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration