Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2019	Apr. 29, 2019
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, 2019
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		106,271,927