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Basis of Presentation (Details) - Akcea [Member] - shares shares in Millions | 1 Months Ended | 7 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Oct. 31, 2018 | Jul. 31, 2017 | Sep. 30, 2018 | Apr. 30, 2018 | Mar. 31, 2018
Basis of Presentation [Abstract] |  |  |  |  |
Percentage ownership before IPO |  | 100.00% |  |  |
Percentage ownership |  | 68.00% | 75.00% | 75.00% | 68.00%
Subsequent Event [Member] |  |  |  |  |
Basis of Presentation [Abstract] |  |  |  |  |
Percentage ownership | 76.00% |  |  |  |
Additional shares of Akcea stock received when TEGSEDI received marketing authorization in the U.S. (in shares) | 1.7 |  |  |  |

X
- Definition The number of shares received from the subsidiary when TEGSEDI received marketing authorization in one or more countries or approval from a government agency, such as the Food and Drug Administration (FDA). + References No definition available. + Details
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- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
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- References No definition available. + Details
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- Definition Percentage of subsidiary's or equity investee's stock owned by parent company before stock transaction. + References No definition available. + Details
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- Details
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- Details
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