0.5% Convertible Senior Notes and Capped Call - Narrative (Details) $ / shares in Units, shares in Millions	1 Months Ended
	May 31, 2018 USD ($) day $ / shares shares	Dec. 31, 2021 USD ($)	Apr. 01, 2021 USD ($)	Mar. 31, 2021 USD ($)
Debt Instrument [Line Items]
Purchase of capped calls	$ 63,200,000
Decrease to the opening balance of accumulated deficit		$ (727,795,000)		$ (587,116,000)
Increase to the opening balance of Convertible senior notes		497,072,000		449,380,000
Convertible Debt | Notes Price Trigger Measurement
Debt Instrument [Line Items]
Threshold trading days | day	20
Threshold consecutive trading days | day	5
Threshold percentage of stock price trigger (less than)	130.00%
Convertible Debt | Stock Price Trigger Measurement
Debt Instrument [Line Items]
Threshold trading days | day	5
Threshold consecutive trading days | day	30
Threshold percentage of stock price trigger (less than)	98.00%
Convertible Senior Notes Due 2023 | Convertible Debt
Debt Instrument [Line Items]
Debt instrument face amount	$ 500,250,000
Stated interest rate	0.50%
Convertible debt, conversion ratio	0.0090244
Convertible debt, conversion price (in dollars per share) | $ / shares	$ 110.81
Debt discount for Conversion Option	$ 102,500,000
Effective interest rate	5.74%
Issuance costs	$ 11,600,000	$ 3,178,000		$ 4,492,000
Debt issuance costs, equity component	9,200,000
Unamortized discount issuance costs	2,400,000
Convertible Senior Notes Due 2023, Over-Allotment Option | Convertible Debt
Debt Instrument [Line Items]
Debt instrument face amount	$ 65,250,000
Capped Calls
Debt Instrument [Line Items]
Convertible debt, conversion price (in dollars per share) | $ / shares	$ 110.81
Initial cap price (in dollars per share) | $ / shares	$ 173.82
Number of shares covered by cap call (in shares) | shares	4.5
Capped Calls | Additional Paid-In Capital
Debt Instrument [Line Items]
Cost incurred related to capped calls	$ 63,200,000
Accounting Standards Update 2020-06
Debt Instrument [Line Items]
Decrease to the opening balance of accumulated deficit			$ 54,200,000
Decrease to the opening balance of additional paid-in capital			100,100,000
Increase to the opening balance of Convertible senior notes			$ 45,900,000