Collaboration Agreements (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Collaborative arrangements [Line Items]
Contracts and grants	$ 12,581,000	$ 15,099,000	$ 45,753,000	$ 44,697,000
Abbott Laboratories TRU016 [Member]
Collaborative arrangements [Line Items]
Contracts and grants		1,600,000	2,700,000	5,500,000
Pfizer CD20 [Member]
Collaborative arrangements [Line Items]
Contracts and grants	$ 356,000	$ 1,200,000	$ 478,000	$ 4,000,000	$ 2,500,000