Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 South San Francisco California	Nov. 30, 2011 South San Francisco California sqft	Apr. 30, 2012 Short-term lease sqft
Minimum contractual payments
2012	$ 5.3		$ 5.3
2013	4.3		4.3
Operating Leased Assets
Additional operating lease, office space						171,000	20,000
Rent expense, net of sublease income	1.3	0.8	3.5	3.6
Construction cost in property, plant and equipment					21.9
Estimated minimum construction asset and related obligation	$ 45.0		$ 45.0