Collaboration and License Agreements (Details 4) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended	3 Months Ended	6 Months Ended	1 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Oct. 31, 2012 Collaboration agreement AstraZeneca	Jun. 30, 2013 Collaboration agreement AstraZeneca	Jun. 30, 2013 Collaboration agreement AstraZeneca	Oct. 31, 2012 Collaboration agreement AstraZeneca Sales milestones	Oct. 31, 2012 Collaboration agreement AstraZeneca Commercialization milestone
Collaboration and License Agreements
Up-front fee received					$ 25,000,000
Milestone payment to be received by company upon milestone achievement								125,000,000
Estimated development period						44 months
Total amount of non-contingent arrangement consideration					26,900,000
Amount of arrangement consideration for clinical trial material supply services and research, development and regulatory activities					1,900,000
Discount rate utilized in analysis (as a percent)					11.50%
Arrangement Consideration allocated to the License Deliverable					24,700,000
Arrangement Consideration allocated to the R&D Services					300,000
Arrangement Consideration allocated to the JDC services					28,000
Arrangement Consideration allocated to the clinical trial material supply services					100,000
Arrangement Consideration allocated to Co-Promotion Deliverable					1,800,000
Remaining Arrangement Consideration received and allocated to the remaining deliverables, which was deferred					300,000
Percentage of costs of clinical trial material supply services and research, development and regulatory activities allocated					55.00%
Collaborative arrangements revenue	9,663,000	14,604,000	12,918,000	26,852,000		400,000	600,000
Net cost sharing offset or incremental expense related to research and development expense						$ 500,000	$ 600,000
Percentage of net profit from commercialization									55.00%
Percentage of net loss from commercialization									55.00%
Prior notice period to terminate the agreement					180 days