Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues:
Collaborative research	$ 1,632	$ 4,191	$ 9,334
Subscription and license fees	217	717	1,366
Total revenues	1,849	4,908	10,700
Operating expenses:
Research and development, including stock-based compensation of $3,249, $3,170 and $3,022, respectively	91,828	78,520	81,238
Increase in fair value of Symphony Icon, Inc. purchase liability	6,766	2,710	0
General and administrative, including stock-based compensation of $2,458, $2,308 and $2,252, respectively	17,350	19,396	19,418
Total operating expenses	115,944	100,626	100,656
Loss from operations	(114,095)	(95,718)	(89,956)
Gain on investments, net	0	141	1,173
Interest income	255	519	880
Interest expense	(2,528)	(2,719)	(2,966)
Other income (expense), net	153	(4,024)	(2,550)
Consolidated net loss before taxes	(116,215)	(101,801)	(93,419)
Income tax benefit	0	26	102
Consolidated net loss	(116,215)	(101,775)	(93,317)
Less: net loss attributable to Symphony Icon, Inc.	0	0	10,537
Net loss attributable to Lexicon Pharmaceuticals, Inc.	$ (116,215)	$ (101,775)	$ (82,780)
Net loss attributable to Lexicon Pharmaceuticals, Inc. per common share, basic and diluted	$ (0.34)	$ (0.34)	$ (0.57)
Shares used in computing net loss attributable to Lexicon Pharmaceuticals, Inc. per common share, basic and diluted	340,761	302,844	145,465