Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Net federal and state operating losses	$ 108,753	$ 101,600
Research and development credits	88,390	86,321
Royalty income	122,391	115,554
Stock-based compensation	26,113	19,374
Capitalized R&D	75,081	62,794
Leasing obligations	3,076	1,842
Other	17,515	4,354
Total deferred tax assets	441,319	391,839
Deferred tax liabilities:
Fixed assets	(678)	(717)
Right of use asset	(2,872)	(1,525)
Total deferred tax liabilities	(3,550)	(2,242)
Valuation allowance	(437,098)	(389,608)
Net deferred tax assets (liabilities)	$ 671
Net deferred tax assets (liabilities)		$ (11)