Collaboration Agreements (Details) (USD $)	3 Months Ended		6 Months Ended			6 Months Ended		12 Months Ended	6 Months Ended								1 Months Ended		6 Months Ended	1 Months Ended	3 Months Ended	6 Months Ended			1 Months Ended	6 Months Ended			3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Apr. 14, 2010	Jun. 30, 2011 Development [Member] Array BioPharma Inc. [Member]	Jun. 30, 2011 Development [Member] Acceleron Pharma [Member]	Dec. 31, 2010 Discovery Stage Programs [Member] Array BioPharma Inc. [Member]	Jun. 30, 2011 Discovery Stage Programs [Member] Acceleron Pharma [Member]	Jun. 30, 2011 Commercial [Member] Array BioPharma Inc. [Member]	Jun. 30, 2011 Commercial [Member] Cabrellis Pharmaceuticals Corp. [Member]	Jun. 30, 2011 Future GlobeImmune Programs [Member] GlobeImmune, Inc. [Member]	Jun. 30, 2011 GI-6200, GI-3000 and GI-10000 [Member] GlobeImmune, Inc. [Member]	Jun. 30, 2011 GI-4000 [Member] GlobeImmune, Inc. [Member]	Jun. 30, 2011 First E.U. Approval [Member] Cabrellis Pharmaceuticals Corp. [Member]	Jun. 30, 2011 Novartis Agreement [Member]	Jun. 30, 2009 Array BioPharma Inc. [Member]	Sep. 30, 2007 Array BioPharma Inc. [Member]	Jun. 30, 2011 Array BioPharma Inc. [Member]	Feb. 28, 2008 Acceleron Pharma [Member]	Jun. 30, 2011 Acceleron Pharma [Member]	Jun. 30, 2011 Acceleron Pharma [Member]	Jun. 30, 2011 Cabrellis Pharmaceuticals Corp. [Member]		May 31, 2009 GlobeImmune, Inc. [Member]	Jun. 30, 2011 GlobeImmune, Inc. [Member]	Apr. 30, 2009 GlobeImmune, Inc. [Member]	Sep. 30, 2007 GlobeImmune, Inc. [Member]	Jun. 30, 2010 Agios Pharmaceuticals, Inc.[Member]	Jun. 30, 2011 The Institute for Advanced Health [Member]
Collaboration Agreements (Textuals) [Abstract]
Potential milestone payment receipts																$ 100,000,000
Milestone payments received																55,000,000
Royalty rate																0.30
Royalty rate																0.35
Upfront payments made																		40,000,000		50,000,000			12,500,000	[1]	30,000,000
Research and development	371,520,000	342,761,000	806,998,000	547,418,000													4,500,000												121,200,000
Potential milestone payments						200,000,000		10,000,000		300,000,000		161,000,000	145,000,000	230,000,000
Potential payment obligation reduction																			50.00%
Equity investment																				5,000,000					10,000,000		100,000	3,000,000
Potential future investment																					7,000,000	7,000,000
Potential milestone payments							510,000,000
Potential milestone payments									437,000,000
Development milestone payments																					7,000,000
Potential reduction in royalty payments																						0.50
Potential milestone payments																							10,000,000
Potential milestone payments																							7,000,000
Potential milestone payments															1,000,000
Potential milestone payments											17,500,000
Generic product units																							20.00%
Potential reduction in royalty payments																										50.00%
Potential reduction in milestone payments																										50.00%
Initial contributions																														41,000,000
Additional contributuions																														50,000,000
Contingent milestone-based payment																														25,000,000
Additional Collaboration Agreement (Textuals) [Abstract]
Equity investment in Agios Series B Convertible Preferred Stock					8,800,000
Ownership Interest					0.1094
Maximum receivable by Agios upon achievement of certain milestones					120,000,000
One time milestone payment					25,000,000
Activities would impact the economic performance			upto 6 years
Potential milestone payments						$ 200,000,000		$ 10,000,000		$ 300,000,000		$ 161,000,000	$ 145,000,000	$ 230,000,000

[1] The Company records its interest and share of losses based on its ownership percentage.