Commitments and Contingencies - Research Collaboration and Licensing Agreements Narrative (Details) - Agreements with Royalty Provisions - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Research Collaboration and Licensing Arrangements [Line Items]
Royalty rate minimum	0.50%
Royalty rate maximum	11.50%
Royalty expense, net of reimbursements from collaborators	$ 56.5	$ 47.0	$ 30.1