Subsequent Events - Additional Information (Details) - Subsequent Event $ in Millions	Apr. 21, 2016 USD ($) Target Agreement
Subsequent Event [Line Items]
Number of collaboration agreements | Agreement	2
Co-Development Agreement
Subsequent Event [Line Items]
Percentage of global development costs	35.00%
Profit and loss sharing percentage	35.00%
Co-Development Agreement | Abb Vie
Subsequent Event [Line Items]
Upfront payment received	$ 20
Reduction in percentage of upfront payment	25.00%
Profit and loss sharing percentage	65.00%
Agreement termination description	AbbVie may terminate the agreement in its entirety or on a country-by-country basis after April 21, 2018 for no reason or at any time for certain development, regulatory or commercialization reasons.
Co-Development Agreement | Maximum | Abb Vie
Subsequent Event [Line Items]
Milestone payments	$ 470
Discovery Collaboration Agreement | Abb Vie
Subsequent Event [Line Items]
Upfront payment received	$ 10
Agreement termination description	AbbVie may terminate the agreement in its entirety or on a country-by-country or target-by-target basis for no reason after April 21, 2017 or at any time for certain development, regulatory or commercialization reasons.
Discovery Collaboration Agreement | Maximum
Subsequent Event [Line Items]
Number of targets | Target	2