Business (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	0 Months Ended
	Jun. 30, 2011	Jul. 14, 2011 New Cambridge Leases [Member]	Jul. 20, 2011 Acorda [Member]
Variable Interest Entity [Line Items]
Area of office building under lease		500,000
Milestone payment payable to Acorda Therapeutics, Inc. (Acorda)			$ 25.0
Business (Textuals) [Abstract]
Interest in subsidiary (less than given percentage)	100.00%