Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document Information [Line Items]
Entity Registrant Name	LEXICON PHARMACEUTICALS, INC./DE
Entity Central Index Key	0001062822
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		105,831,868