Commitments And Contingencies (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Commitments for purchase of property, plant and equipment	$ 0.1	$ 3.0
Commitments on investments	$ 2.0	$ 2.6

Capital commitments for purchase of property plant and equipment.

No definition available.

Name:	eln_CapitalCommitmentsForPurchaseOfPropertyPlantAndEquipment
Namespace Prefix:	eln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant