Buildings and Land Held for Sale (Details) $ in Millions	1 Months Ended
Jan. 31, 2016 USD ($)
Property, Plant and Equipment Impairment or Disposal [Abstract]
Real Estate Selling Price	$ 21.2

In January 2016, Lexicon entered into a Real Estate Purchase and Sale Agreement. This represents the selling price of Lexicon's land and buildings.

No definition available.

Name:	lxrx_RealEstateSellingPrice
Namespace Prefix:	lxrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration