Employee Benefit Plans - Unamortized Stock-based Compensation (Details) $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation (in thousands)	$ 175,464
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation (in thousands)	$ 129,340
Weighted average vesting period (in years)	2 years 3 months 18 days
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation (in thousands)	$ 34,430
Weighted average vesting period (in years)	2 years 2 months 12 days
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation (in thousands)	$ 6,130
Weighted average vesting period (in years)	2 years 3 months 18 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation (in thousands)	$ 5,564
Weighted average vesting period (in years)	1 year 7 months 6 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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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

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