Collaboration and License Agreements - Mylan Collaboration Agreement (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) milestone_payment	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments		$ 20,000	$ 12,000
Mylan Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-refundable upfront payment	$ 45,000
Milestone payment on collaboration agreement	$ 200,000
Percentage of cost sharing arrangement under collaborative and license agreements	50.00%
Number of Milestone Payments | milestone_payment	2
Milestone payments	$ 60,000
Payments for milestones applied to cost share percentage	32,900
Accounting Standards Update 2009 to 2013 | Mylan Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total arrangement consideration	45,000
Portion of revised arrangement consideration allocated to the first initial product license as a result of termination of product	8,200
Portion of revised arrangement consideration allocated to the joint steering committee unit of accounting as a result of termination of product	51
Deferred revenue amortized to research and development revenue	38,700
Deferred revenue included in current liabilities	7,300
Deferred revenue included in non-current liabilities	31,400
Minimum | Accounting Standards Update 2009 to 2013 | Mylan Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Portion of revised arrangement consideration allocated to each of the three additional product licenses as a result of termination of product	5,700
Maximum | Accounting Standards Update 2009 to 2013 | Mylan Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Portion of revised arrangement consideration allocated to each of the three additional product licenses as a result of termination of product	$ 9,000