Income Taxes (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Net loss before income taxes		$ (43,172,000)	$ (32,465,000)	$ (46,481,000)
Income tax provision		(4,331,000)	1,572,000	8,272,000
Effective tax rate		10.04%	(4.84%)	(17.89%)
Accelerated recognition of milestone payment	10,000,000
Valuation allowance increased		12,900,000	12,900,000	30,800,000
Unrecognized tax benefits		3,936,000	4,128,000	889,000	358,000
Gross unrecognized tax that would decrease effective tax rate, if recognized		600,000	1,200,000
Research and development credit and orphan drug credit, expiration dates		2024 through 2031
Federal tax provision at statutory rate		35.00%	35.00%	35.00%
Federal [Member]
Operating loss carryforwards		77,300,000
Operating loss carryforwards, expiration dates		2031
Research and development credit and orphan drug credit		13,300,000
State [Member]
Operating loss carryforwards		154,100,000
Operating loss carryforwards, expiration dates		at various dates between the years 2015 and 2031
California Credit Carryforwards [Member]
Research and development credit and orphan drug credit		$ 1,400,000