Stock-Based Compensation - Additional Information (Details) shares in Millions, $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($) shares
Stock-based compensation
Total unrecognized compensation cost related to unvested Awards \| $	$ 47
Weighted average period of recognition related to unvested equity awards (in years)	2 years
Common Class A
Stock-based compensation
Shares reserved for future issuance upon exercise of stock options	25.4
Common Class B
Stock-based compensation
Shares reserved for future issuance upon exercise of stock options	1.8

Aggregate number of common shares reserved for future issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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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=116856206&loc=d3e5070-113901

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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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