License And Other arrangements (Details) (USD $)	3 Months Ended		1 Months Ended		3 Months Ended	1 Months Ended		3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2010 Janssen Pharmaceutica N.V. [Member]	Aug. 31, 2010 Janssen Pharmaceutica N.V. [Member]	Mar. 31, 2013 Janssen Pharmaceutica N.V. [Member]	Aug. 31, 2011 Santarus Inc. [Member]	Jul. 31, 2008 Santarus Inc. [Member]	Mar. 31, 2013 Santarus Inc. [Member]	Mar. 31, 2012 Santarus Inc. [Member]	Mar. 31, 2012 Boehringer Ingelheim International GMBH [Member]	Mar. 31, 2012 Ironwood Pharmaceuticals, Inc. [Member]
Royalty receivable percentage, 2011						26.50%
Royalty receivable percentage, 2012						29.50%
Royalty receivable percentage, 2013 and 2014						32.00%
Royalty receivable percentage, 2015 and thereafter						34.50%
Royalties	$ 14,081,000	$ 9,421,000						$ 13,300,000	$ 9,200,000
License and other revenue	2,964,000	5,305,000			2,200,000			400,000	1,000,000
Upfront agreement fee received				5,000,000			12,000,000
Upfront agreement fee deferred revenue balance								4,100,000
Milestone revenue received			$ 5,000,000							$ 2,500,000	$ 1,000,000
Percent of out-of-pocket costs reimbursed to company						70.00%
Percent of out-of-pocket costs reimbursed by company						30.00%