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Financial Instruments (Details Textual 1) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Financial Instruments (Textual) |  |  |
Acquisition of TYSABRI rights | $ 3,262,719,000 | $ 0 | $ 0
Original maturities of commercial paper and short-term debt securities | less than 90 days |  |
Average maturity of marketable securities, months | 13 months | 14 months |
TYSABRI product |  |  |
Financial Instruments (Textual) |  |  |
Acquisition of TYSABRI rights | 3,250,000,000 |  |
Strategic Investments |  |  |
Financial Instruments (Textual) |  |  |
Impairment charges | $ 2,800,000 | $ 5,500,000 | $ 9,900,000

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- Details
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- Definition Impairment charges related to investments in privately held companies. + References No definition available. + Details
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- Definition Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585 + Details
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