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Debt - 2028 Convertible Notes (Details) | Mar. 16, 2021 USD ($) day $ / shares | Feb. 28, 2020 USD ($) | Sep. 30, 2021 USD ($) $ / shares | Dec. 31, 2020 USD ($) $ / shares
--- | --- | --- | --- | ---
Debt Instrument [Line Items] |  |  |  |
Total net proceeds |  | $ 344,722,000 |  |
Class A voting common stock |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Common stock, par value (in usd per share) | $ / shares |  |  | $ 0.001 | $ 0.001
2028 Convertible Notes | Class A voting common stock |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Common stock, par value (in usd per share) | $ / shares | $ 0.001 |  |  |
2028 Convertible Notes | Convertible notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Principal | $ 250,000,000 |  | $ 250,000,000 | $ 0
Stated rate | 0.50% |  |  |
Total net proceeds | $ 216,956,000 |  |  |
Conversion price (in usd per share) | $ / shares | $ 179.27 |  |  |
Cash redemption price, percent | 100.00% |  |  |
Conversion option | $ 66,908,000 |  |  |
Effective interest rate | 5.125% |  |  |
Carrying amount of equity component | $ 39,389,000 |  |  |
Annual effective interest rate | 4.959% |  |  |
Issuance costs attributable to the liability component | $ 5,525,000 |  |  |
Issuance costs | $ 2,019,000 |  | $ 2,019,000 | $ 0
2028 Convertible Notes | Convertible notes | Class A voting common stock |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Conversion ratio | 5.5781 |  |  |
2028 Convertible Notes | Convertible notes | Conversion option 1 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Trading days | day | 20 |  |  |
Consecutive trading days | day | 30 |  |  |
2028 Convertible Notes | Convertible notes | Conversion option 1 | Class A voting common stock |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Stock price trigger percent | 130.00% |  |  |
2028 Convertible Notes | Convertible notes | Conversion option 2 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Trading days | day | 5,000 |  |  |
Consecutive trading days | day | 10,000 |  |  |
2028 Convertible Notes | Convertible notes | Conversion option 2 | Class A voting common stock |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Stock price trigger percent | 98.00% |  |  |

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