Condensed Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Revenues:
Product	$ 975,488	$ 907,102
Unconsolidated joint business	284,552	256,124
Other	31,974	40,116
Total revenues	1,292,014	1,203,342
Cost and expenses:
Cost of sales, excluding amortization of acquired intangible assets	133,197	103,113
Research and development	355,962	293,633
Selling, general and administrative	300,089	244,516
Collaboration profit sharing	85,894	74,794
Amortization of acquired intangible assets	45,961	53,216
Fair value adjustment of contingent consideration	1,258	1,200
Restructuring charge	283	16,587
Total cost and expenses	922,644	787,059
Income from operations	369,370	416,283
Other income (expense), net	15,144	9,951
Income before income tax expense	384,514	426,234
Income tax expense	82,148	117,468
Net income	302,366	308,766
Net income (loss) attributable to noncontrolling interests, net of tax	(295)	14,435
Net income attributable to Biogen Idec Inc.	$ 302,661	$ 294,331
Net income per share:
Basic earnings per share attributable to Biogen Idec Inc.	$ 1.26	$ 1.22
Diluted earnings per share attributable to Biogen Idec Inc.	$ 1.25	$ 1.20
Weighted-average shares used in calculating:
Basic earnings per share attributable to Biogen Idec Inc.	239,754	241,536
Diluted earnings per share attributable to Biogen Idec Inc.	241,828	244,551

Payments are made to Elan for their share of rest of world net operating profits to effect an equal sharing of collaboration operating profit. These payments include the reimbursement of our portion of third-party royalties that Elan pays on behalf of the collaboration, relating to sales outside of the U.S. These amounts are reflected in the collaboration profit sharing line in our consolidated statement of income. As sales of Tysabri outside the U.S. increase, our collaboration profit sharing expense will increase.

No definition available.