Summary of Significant Accounting Policies (Details 4) (USD $)					12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 Sales Revenue, Net Revenue Concentration Risk Takeda Pharmaceutical Company Limited (outside the U.S.)	Dec. 31, 2011 Sales Revenue, Net Revenue Concentration Risk Takeda Pharmaceutical Company Limited (outside the U.S.)	Dec. 31, 2010 Sales Revenue, Net Revenue Concentration Risk Takeda Pharmaceutical Company Limited (outside the U.S.) Maximum	Dec. 31, 2012 Sales Revenue, Net Revenue Concentration Risk AmerisourceBergen Drug Corporation.	Dec. 31, 2011 Sales Revenue, Net Revenue Concentration Risk AmerisourceBergen Drug Corporation.	Dec. 31, 2010 Sales Revenue, Net Revenue Concentration Risk AmerisourceBergen Drug Corporation.	Dec. 31, 2012 Sales Revenue, Net Revenue Concentration Risk McKesson Corporation	Dec. 31, 2011 Sales Revenue, Net Revenue Concentration Risk McKesson Corporation	Dec. 31, 2010 Sales Revenue, Net Revenue Concentration Risk McKesson Corporation Maximum	Dec. 31, 2012 Sales Revenue, Net Revenue Concentration Risk Cardinal Health, Inc	Dec. 31, 2011 Sales Revenue, Net Revenue Concentration Risk Cardinal Health, Inc	Dec. 31, 2010 Sales Revenue, Net Revenue Concentration Risk Cardinal Health, Inc Maximum	Dec. 31, 2012 Sales Revenue, Net Revenue Concentration Risk GPO	Dec. 31, 2010 Sales Revenue, Net Revenue Concentration Risk Metro Medical Supply, Inc	Dec. 31, 2012 Sales Revenue, Net Revenue Concentration Risk Metro Medical Supply, Inc Maximum	Dec. 31, 2011 Sales Revenue, Net Revenue Concentration Risk Metro Medical Supply, Inc Maximum	Dec. 31, 2012 Sales Revenue, Net Geographical Concentration Risk	Dec. 31, 2011 Sales Revenue, Net Geographical Concentration Risk	Dec. 31, 2010 Sales Revenue, Net Geographical Concentration Risk
Investment Concentration Risk
Cash, cash equivalents and investments	$ 227,000,000
Investment in institutional money market funds	24,100,000
Cash	46,293,000	63,474,000	112,646,000	50,126,000
Amount invested in a single money market fund collateralized by U.S. treasury and government agency securities	$ 16,300,000
Customers representing 10% or more of revenues
Percentage of revenues from major customer					31.00%	13.00%	10.00%	34.00%	41.00%	36.00%	17.00%	21.00%	10.00%	12.00%	13.00%	10.00%	32.00%	21.00%	10.00%	10.00%
Percentage of revenues From customers outside of the U.S.
Approximate percentage of revenues from customers outside the U.S.																					32.00%	14.00%	10.00%