Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
3.75% Convertible notes due 2023
Liabilities
Coupon interest rate	3.75%	3.75%
5.00% Convertible notes due 2027 | Unsecured Debt
Liabilities
Coupon interest rate	5.00%	5.00%
Level 1
Assets
Total cash equivalents	$ 171,824	$ 398,834
Liabilities
Total convertible notes payable	0	0
Level 1 | 3.75% Convertible notes due 2023
Liabilities
Total convertible notes payable	0	0
Level 1 | 5.00% Convertible notes due 2027
Liabilities
Total convertible notes payable	0	0
Level 1 | Money market funds
Assets
Total cash equivalents	171,824	398,834
Level 1 | Government-backed securities
Assets
Total cash equivalents	0	0
Level 1 | Corporate debt securities
Assets
Total cash equivalents	0	0
Level 1 | Agency securities
Assets
Total cash equivalents	0	0
Level 2
Assets
Total cash equivalents	245,622	400,536
Liabilities
Total convertible notes payable	100,909	494,900
Level 2 | 3.75% Convertible notes due 2023
Liabilities
Total convertible notes payable	0	322,111
Level 2 | 5.00% Convertible notes due 2027
Liabilities
Total convertible notes payable	100,909	172,789
Level 2 | Money market funds
Assets
Total cash equivalents	0	0
Level 2 | Government-backed securities
Assets
Total cash equivalents	200,000	296,000
Level 2 | Corporate debt securities
Assets
Total cash equivalents	45,622	0
Level 2 | Agency securities
Assets
Total cash equivalents	0	104,536
Level 3
Assets
Total cash equivalents	0	0
Liabilities
Total convertible notes payable	0	0
Level 3 | 3.75% Convertible notes due 2023
Liabilities
Total convertible notes payable	0	0
Level 3 | 5.00% Convertible notes due 2027
Liabilities
Total 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
Level 3 | Agency securities
Assets
Total cash equivalents	$ 0	$ 0