Collaboration Agreements - Schedule of Contract Balances, Antibody Collaboration (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 468.3	$ 260.6
Sanofi Collaboration Agreement, Antibody
Disaggregation of Revenue [Line Items]
Accounts receivable, net	458.4	272.7
Deferred revenue	$ 401.4	$ 328.8

Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer.

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