Collaborative Arrangements Collaborative Arrangements - Other In-License Agreements (Details) - USD ($)	1 Months Ended
	Dec. 31, 2018	Jul. 31, 2016
Moderna Therapeutics, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Up-front payment		$ 20,000,000
Collaborative arrangement development and regulatory potential milestone payments maximum		$ 275,000,000
Arbor
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Up-front payment	$ 30,000,000
Collaborative arrangement development and regulatory potential milestone payments maximum	337,500,000.0
Investment in collaborative partner, pursuant to convertible loan agreement	$ 15,000,000