Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 1,186,281	$ 602,562
Marketable securities	675,065	620,167
Accounts receivable, net	1,091,232	824,406
Due from unconsolidated joint business, net	269,999	252,662
Inventory	753,063	659,003
Other current assets	396,471	226,134
Total current assets	4,372,111	3,184,934
Marketable securities	1,371,431	625,772
Property, plant and equipment, net	1,724,129	1,750,710
Intangible assets, net	4,129,754	4,474,653
Goodwill	1,541,204	1,232,916
Investments and other assets	565,513	594,350
Total assets	13,704,142	11,863,335
Current liabilities:
Current portion of notes payable	3,220	3,494
Taxes payable	159,638	179,685
Accounts payable	233,629	219,913
Accrued expenses and other	1,544,160	1,355,187
Total current liabilities	1,940,647	1,758,279
Notes payable	583,977	592,433
Long-term deferred tax liability	90,357	232,554
Other long-term liabilities	658,276	659,231
Total liabilities	3,273,257	3,242,497
Commitments and contingencies
Biogen Idec Inc. shareholders' equity
Preferred stock, par value $0.001 per share	0	0
Common stock, par value $0.0005 per share	129	128
Additional paid-in capital	4,150,007	4,023,651
Accumulated other comprehensive loss	(37,987)	(27,745)
Retained earnings	8,400,455	6,349,135
Treasury stock, at cost	(2,084,908)	(1,724,927)
Total Biogen Idec Inc. shareholders’ equity	10,427,696	8,620,242
Noncontrolling interests	3,189	596
Total equity	10,430,885	8,620,838
Total liabilities and equity	$ 13,704,142	$ 11,863,335