Collaborative Arrangements and Acquisitions - Concert Pharmaceuticals (Details) - Concert Pharmaceuticals - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jul. 28, 2017	Sep. 30, 2017
Subsequent Event
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, development and commercialization rights potential maximum milestone payments	$ 160
Collaborative arrangement, additional maximum milestone payments based on regulatory approval	$ 90
Scenario, Forecast
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative funding		$ 160