Stock-based Compensation - Unrecognized Compensation Costs (Details) $ in Millions	Mar. 31, 2021 USD ($)
Stock-based compensation
Total unrecognized compensation cost related to non-vested stock option awards	$ 133.2
Weighted-average period over which unrecognized compensation cost will be recognized	2 years 8 months 23 days
Restricted Stock Units
Stock-based compensation
Total unrecognized compensation cost related to non-vested stock awards	$ 120.5
Weighted-average period over which unrecognized compensation cost will be recognized	3 years 3 months 3 days

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

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