Statements of Comprehensive Loss Parentheticals (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock-based compensation expense associated with research and development expense	$ 4,284	$ 6,376	$ 7,096
Stock-based compensation expense associated with general and administrative expense	$ 6,293	$ 6,898	$ 7,122

Stock-based compensation expense associated with general and administrative expense.

No definition available.

Name:	lxrx_StockBasedCompensationExpenseAssociatedWithGeneralAndAdministrativeExpense
Namespace Prefix:	lxrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration