Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Level 1
Assets
Total cash equivalents	$ 500,885	$ 361,822
Liabilities
Convertible notes payable	0	0
Level 1 | Money market funds
Assets
Total cash equivalents	500,885	361,822
Level 1 | Government-backed securities
Assets
Total cash equivalents	0	0
Level 1 | Corporate debt securities
Assets
Total cash equivalents	0	0
Level 2
Assets
Total cash equivalents	774,250	1,056,922
Liabilities
Convertible notes payable	323,112	447,509
Level 2 | Money market funds
Assets
Total cash equivalents	0	0
Level 2 | Government-backed securities
Assets
Total cash equivalents	179,500	266,250
Level 2 | Corporate debt securities
Assets
Total cash equivalents	594,750	790,672
Level 3
Assets
Total cash equivalents	0	0
Liabilities
Convertible notes payable	0	0
Level 3 | Money market funds
Assets
Total cash equivalents	0	0
Level 3 | Government-backed securities
Assets
Total cash equivalents	0	0
Level 3 | Corporate debt securities
Assets
Total cash equivalents	$ 0	$ 0