Basis of Presentation and Summary of Significant Accounting Policies (Details 3) (USD $)							6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2012 Sales Revenue, Net Minimum	Jun. 30, 2011 Sales Revenue, Net Minimum	Jun. 30, 2012 Sales Revenue, Net Revenue Concentration Risk Takeda Pharmaceutical Company Limited (outside the U.S.)	Jun. 30, 2011 Sales Revenue, Net Revenue Concentration Risk Takeda Pharmaceutical Company Limited (outside the U.S.)	Jun. 30, 2012 Sales Revenue, Net Revenue Concentration Risk AmerisourceBergen Drug Corporation.	Jun. 30, 2011 Sales Revenue, Net Revenue Concentration Risk AmerisourceBergen Drug Corporation.	Jun. 30, 2012 Sales Revenue, Net Revenue Concentration Risk McKesson Corporation	Jun. 30, 2011 Sales Revenue, Net Revenue Concentration Risk McKesson Corporation	Jun. 30, 2012 Sales Revenue, Net Revenue Concentration Risk Cardinal Health, Inc	Jun. 30, 2011 Sales Revenue, Net Revenue Concentration Risk Cardinal Health, Inc	Jun. 30, 2012 Sales Revenue, Net Revenue Concentration Risk GPO	Jun. 30, 2012 Sales Revenue, Net Geographical Concentration Risk	Jun. 30, 2011 Sales Revenue, Net Geographical Concentration Risk
Investment Concentration Risk
Cash, cash equivalents and investments	$ 207,200,000
Investment in institutional money market funds	27,400,000
Amount invested in a single money market fund collateralized by U.S. treasury and government agency securities	13,000,000
Cash and cash equivalents	$ 30,678,000	$ 63,474,000	$ 79,956,000	$ 112,646,000
Customers representing 10% or more of revenues
Percentage required for qualification as major customer					10.00%	10.00%
Percentage of revenues from major customer							40.00%	16.00%	30.00%	40.00%	14.00%	19.00%	10.00%	12.00%	32.00%
Percentage of revenues From customers outside of the U.S.
Approximate percentage of revenues from customers outside the U.S.																40.00%	17.00%