Collaborative and Other Arrangements - Kymera, Moderna and Other In-License Agreements (Details)	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) target
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment	$ 125,800,000	$ 84,600,000	$ 63,300,000
Kymera Therapeutics
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment			$ 50,000,000
Right to license, number of targets (up to) | target			6
Collaborative arrangement development and regulatory potential milestone payments maximum			$ 170,000,000
Investment in collaborative partner, pursuant to convertible loan agreement		20,000,000
Moderna Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment		75,000,000
Collaborative arrangement development and regulatory potential milestone payments maximum		380,000,000
ApolLo1 Bio, LLC
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, milestone payment	15,000,000
Collaborative arrangement, option payment	60,000,000
Mammoth Biosciences, Inc
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment	31,000,000
Arbor Biotechnologies, Inc
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment	$ 25,000,000
Skyhawk Therapeutics Inc
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment		$ 40,000,000
Molecular Templates, Inc
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment			$ 25,900,000