Forendo In-Licensing Agreement (Details) - USD ($)	1 Months Ended					12 Months Ended
	Apr. 30, 2015	Feb. 28, 2015	Dec. 31, 2014	Oct. 31, 2014	Aug. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Issuance of common stock, value								$ 792,000
Accrued license fees			$ 2,500,000			$ 0	$ 2,500,000
Research and development						$ 14,649,000	$ 21,288,000	$ 5,123,000
Common Stock
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Issuance of common stock (shares)		6,043,955			300,000		2,600,000
Forendo License Agreement | Option To Purchase A Drug Product
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Payment of license fees				$ 5,000,000
Accrued license fees	$ 2,500,000
Maximum product license agreement, regulatory milestone payment				42,500,000.0
Maximum product license agreement, commercial milestone payment				$ 260,000,000
Research and development			$ 13,600,000
Transaction costs	$ 200,000
Forendo License Agreement | Option To Purchase A Drug Product | Common Stock
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Issuance of common stock (shares)				3,600,000
Issuance of common stock, value				$ 5,900,000