Accounts Receivable (Details Textual) In Millions, unless otherwise specified	9 Months Ended			9 Months Ended		9 Months Ended
	Sep. 30, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2011 EUR (€)	Sep. 30, 2012 Spain [Member] USD ($)	Dec. 31, 2011 Spain [Member] USD ($)	Sep. 30, 2012 Portugal [Member] USD ($)	Dec. 31, 2011 Portugal [Member] USD ($)	Sep. 30, 2012 Italy [Member] USD ($)	Dec. 31, 2011 Italy [Member] USD ($)
Accounts Receivable (Textual) [Abstract]
Payment terms of accounts receivable arising from product sales	30 to 90 days
Minimum term for accounts receivable	30 days
Maximum term for accounts receivable	90 days
Accounts receivable outstanding for greater than one year	$ 3.9	$ 56.0
Decrease in accounts receivable in Portugal						21.2
Decrease in accounts receivable in Spain				112.0
Accounts Receivable, Net				73.5	134.0	26.8	32.9	108.4	68.1
Payment in case of any unfavorable determination received			30.7
Deferred revenue on sales of TYSABRI made in Italy								$ 46.6	$ 13.8