Collaborative Arrangements - Parion Sciences, Inc. (Details) - USD ($)	Jun. 04, 2015	Mar. 31, 2016	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Commercial milestones and royalties discount rate (percentage)	6.60%
Development milestones discount rate low end of range (percentage)	4.10%
Development milestones discount rate high end of range (percentage)	5.90%
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net:
Intangible assets		$ 284,340,000	$ 284,340,000
Goodwill		50,384,000	50,384,000
Deferred tax liability		$ (112,259,000)	$ (110,439,000)
Parion Sciences, Inc
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Prior to marketing approval, time period of notice required to terminate (in days)	90 days
Subsequent to marketing approval, time period of notice required to terminate (in days)	180 days
Change of control prior to clinical trial, time period of notice required to terminate (in days)	30 days
Term of agreement following first commercial sale (in years)	10 years
Consideration Paid
Up-front payment	$ 80,000,000
Fair value of contingent milestone and royalty payments	175,340,000
Total consideration paid	255,340,000
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net:
Intangible assets	255,340,000
Goodwill	10,468,000
Deferred tax liability	(91,023,000)
Net other assets (liabilities)	(10,468,000)
Net assets attributable to noncontrolling interests	164,317,000
ENaC Inhibitors in CF | Parion Sciences, Inc
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement development and regulatory potential milestone payments maximum	490,000,000
Collaborative arrangement regulatory potential milestone payments maximum, global filling and approval	360,000,000
Enac Inhibitors in Non Cf | Parion Sciences, Inc
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement development and regulatory potential milestone payments maximum	370,000,000
Additional Enac Inhibitors | Parion Sciences, Inc
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement development and regulatory potential milestone payments maximum	$ 230,000,000