Collaboration and License Agreements - Schedule of Accounts Receivable and Deferred Revenue Information, IO Collaboration (Details) - Sanofi Collaboration Agreement, Immuno-oncology - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ (16.7)	$ 77.9
Deferred revenue	$ 568.0	$ 289.9