Fair Value of Financial Instruments - Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets:
Derivative Asset, Statement of Financial Position	Convertible note hedges	Convertible note hedges
Liabilities:
Derivative Liability, Statement of Financial Position	Note hedge warrants	Note hedge warrants
Recurring basis
Assets:
Convertible note hedges	$ 1,428	$ 1,115
Total assets measured at fair value	559,134	598,083
Liabilities:
Note hedge warrants	899	1,316
Total liabilities measured at fair value	899	1,316
Recurring basis | Money market funds
Assets:
Cash and cash equivalents	278,970	595,233
Restricted cash	1,735	1,735
Recurring basis | Repurchase agreements
Assets:
Cash and cash equivalents	277,001
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total assets measured at fair value	557,706	596,968
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Assets:
Cash and cash equivalents	278,970	595,233
Restricted cash	1,735	1,735
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Repurchase agreements
Assets:
Cash and cash equivalents	277,001
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Convertible note hedges	1,428	1,115
Total assets measured at fair value	1,428	1,115
Liabilities:
Note hedge warrants	899	1,316
Total liabilities measured at fair value	$ 899	$ 1,316