Notes Payable (Details) (USD $)	12 Months Ended		0 Months Ended	12 Months Ended
	Dec. 31, 2013	Jan. 31, 2013	Jan. 04, 2013 Notes Payable	Dec. 31, 2013 Notes Payable	Dec. 31, 2013 Notes Payable From and including January 1, 2014 to and including December 31, 2014	Dec. 31, 2013 Notes Payable From and including January 1, 2015 to and including December 31, 2015	Dec. 31, 2013 Notes Payable From and including January 1, 2016 to and including December 31, 2016	Dec. 31, 2013 Notes Payable From and including January 1, 2017 and thereafter
Notes Payable
Payment start date					Jan. 01, 2014	Jan. 01, 2015	Jan. 01, 2016	Jan. 01, 2017
Payment end date					Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2016
Aggregate principal amount of notes issued in private placement			$ 175,000,000
Annual interest rate of notes (as a percent)		11.00%	11.00%
Percentage of net sales of LINZESS considered to determine quarterly payments on the notes				7.50%
Margin over U.S. Treasury Rate (as a percent)				1.00%
Redemption Percentage					112.00%	105.50%	102.75%	100.00%
Upfront cash proceeds	175,000,000		175,000,000
Discount on issuance of debt			400,000
Debt issuance costs capitalized			7,300,000
Estimated fair value				$ 183,800,000