September 2009 Financial Transactions (Details) (USD $)	12 Months Ended			1 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 28, 2011 Olmsted Park S.A. [Member]	Sep. 30, 2009 Olmsted Park S.A. [Member] agreements	Dec. 31, 2011 Olmsted Park S.A. [Member]	Oct. 31, 2011 Olmsted Park S.A. [Member]
2012 Notes
Face amount of 2012 Notes					$ 155,000,000
Proceeds from issuance of 2012 Notes					122,200,000
Proceeds from milestone payment related to the acceptance of Janssen's MAA				50,000,000
Portion of 2012 Notes redeemed upon achievement of certain approval milestone pursuant to the Janssen collaboration				50,000,000
Earned remaining milestone payment to be received in the fourth quarter of 2011							105,000,000
Sale of Contingent Milestone Payments
Number of purchase agreements entered into related to sale of contingent launch milestone payments pursuant to the Janssen collaboration (agreements)					2
Value of potential contingent launch milestone payments sold pursuant to the Janssen collaboration					95,000,000
Proceeds from sale of potential contingent launch milestone payments pursuant to the Janssen collaboration					32,800,000
Expenses and Losses (Gains):
Interest expense related to 2012 Notes						21,687,000
Change in fair value of embedded derivative related to 2012 Notes						(400,000)
Change in fair value of free-standing derivatives related to the sale of milestone payments	0	0	16,801,000			17,201,000
Total September 2009 financial transaction expenses						$ 38,488,000