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Commitments and Contingences (Details Textual) (USD $) | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2014 | Jun. 30, 2013 | Dec. 31, 2013
Business Acquisition, Contingent Consideration [Line Items] |  |  |
Payment of contingent payment for acquisition | $ 25,000,000 | $ 0 |
Increase to goodwill | 131,900,000 |  | 35,700,000
Fumapharm AG [Member] | TECFIDERA [Member] |  |  |
Business Acquisition, Contingent Consideration [Line Items] |  |  |
Payment of contingent payment for acquisition | 25,000,000 |  |
Increase to goodwill | 150,000,000 |  |
One billion [Member] | Fumapharm AG [Member] |  |  |
Business Acquisition, Contingent Consideration [Line Items] |  |  |
Cumulative sales level | 1,000,000,000.0 |  | 1,000,000,000
Two billion [Member] | Fumapharm AG [Member] |  |  |
Business Acquisition, Contingent Consideration [Line Items] |  |  |
Cumulative sales level | $ 2,000,000,000 |  |

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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
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- Definition The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase. + 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 (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585 + Details
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