Commitments and Contingencies (Details) (USD $)	12 Months Ended															12 Months Ended											12 Months Ended
	Dec. 31, 2013 sqft		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Inventories [Member]		Dec. 31, 2013 Long-term Debt [Member]		Dec. 31, 2013 Research and Development Arrangement [Member]		Dec. 31, 2013 Operating Leases [Member]		Dec. 31, 2013 Selling, General and Administrative [Member]		Dec. 31, 2013 Research and Development and Selling, General Administrative [Member]	Dec. 31, 2013 Biogen Idec and HRI [Member]	Dec. 31, 2012 Biogen Idec and HRI [Member]	Dec. 31, 2011 Biogen Idec and HRI [Member]	Dec. 31, 2013 Cleviprex [Member]	Dec. 31, 2012 Cleviprex [Member]	Dec. 31, 2011 Cleviprex [Member]	Dec. 31, 2013 Recothrom [Member]	Dec. 31, 2012 Recothrom [Member]	Dec. 31, 2011 Recothrom [Member]	Dec. 31, 2013 Plantex [Member]	Dec. 31, 2013 Lonza Braine [Member] Inventories [Member]	Dec. 31, 2013 Targanta [Member]	Dec. 31, 2013 Incline Therapeutics, Inc. [Member]	Dec. 31, 2013 ProFibrix [Member]	Dec. 31, 2013 Alnylam Pharmaceuticals, Inc. [Member]	Dec. 31, 2013 Pfizer [Member]	Dec. 31, 2013 AstraZeneca [Member]	Jun. 29, 2012 Convertible Debt [Member]
Future Estimated Contract Obligations
2014	$ 93,922,000	[1]			$ 47,096,000	[1]	$ 3,781,000	[1]	$ 33,382,000	[1]	$ 7,729,000	[1]	$ 1,934,000	[1]												$ 26,600,000
2015	33,240,000	[1]			20,958,000	[1]	3,781,000	[1]	882,000	[1]	6,787,000	[1]	832,000	[1]												20,100,000
2016	10,988,000	[1]			870,000	[1]	3,781,000	[1]	117,000	[1]	6,092,000	[1]	128,000	[1]
2017	282,534,000	[1]			130,000	[1]	276,891,000	[1]	53,000	[1]	5,386,000	[1]	74,000	[1]
2018	4,592,000	[1]			130,000	[1]	0	[1]	3,000	[1]	4,459,000	[1]	0	[1]
Later Years	24,512,000	[1]			130,000	[1]	0	[1]	0	[1]	24,382,000	[1]	0	[1]
Total	449,788,000	[1]			69,314,000	[1]	288,234,000	[1]	34,437,000	[1]	54,835,000	[1]	2,968,000	[1]	13,800,000
Convertible senior notes (due 2017)	236,088,000		226,109,000																														275,000,000
Square footage of real estate property	173,146
Operating leases, percent	85.00%
Aggregate rent expense under property leases	7,300,000		5,800,000	7,300,000
Payment for milestone met																											49,400,000.0	205,000,000.0	140,000,000.0	180,000,000.0	422,000,000	54,500,000.0
Additional payments																											40,000,000	115,500,000
Royalties																140,700,000	122,200,000	108,200,000	1,000,000	1,000,000	800,000	7,400,000	7,400,000	7,400,000
Costs related to production																									$ 8,500,000

[1] This table does not include any milestone and royalty payments which may become payable to third-parties for which the timing and likelihood of such payments are not known, as discussed below.