Collaboration and License Agreements [Abstract]

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In October 2014, Lexicon entered into a License and Collaboration Agreement with Ipsen Pharma SAS for the development and commercialization of Lexicon's drug candidate telotristat etiprate (LX1032) outside the United States and Japan. This represents the maximum regulatory and commercial launch milestone payments.

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- Definition

In October 2014, Lexicon entered into a License and Collaboration Agreement with Ipsen Pharma SAS for the development and commercialization of Lexicon's drug candidate telotristat etiprate (LX1032) outside the United States and Japan. This is the amount of the upfront payment allocated to the committee participation deliverable.

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- Definition

In October 2014, Lexicon entered into a License and Collaboration Agreement with Ipsen Pharma SAS for the development and commercialization of Lexicon's drug candidate telotristat etiprate (LX1032) outside the United States and Japan. This represents the amount of the upfront payment allocated to the development services deliverable.

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No definition available.

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- Definition

In October 2014, Lexicon entered into a License and Collaboration Agreement with Ipsen Pharma SAS for the development and commercialization of Lexicon's drug candidate telotristat etiprate (LX1032) outside the United States and Japan. This represents the amount of the upfront payment allocated to the license deliverable.

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No definition available.

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Collaboration and License Agreements (Details) € in Millions, $ in Millions	1 Months Ended			9 Months Ended	12 Months Ended
	Mar. 31, 2015 USD ($)	Oct. 31, 2014 USD ($)	Oct. 31, 2014 EUR (€)	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Collaboration and License Agreements [Abstract]
Ipsen Maximum Regulatory And Commercial Milestones		$ 34.0
Ipsen Maximum Sales Milestones \| €			€ 72
Ipsen Total Upfront Payments	$ 24.5
Ipsen Revenue Allocated to License Deliverable				$ 1.4	$ 21.2
Ipsen Revenue Allocated to Development Deliverable		1.7
Ipsen Revenue Allocated to Committee Deliverable		$ 0.1
Ipsen Revenue Recognized				$ 2.3