Document and Entity Information	12 Months Ended
	Dec. 31, 2012
Entity Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Trading Symbol	ELN
Entity Registrant Name	ELAN CORP PLC
Entity Central Index Key	0000737572
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	594,949,536
Entity Voluntary Filers	No