Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Purchase Agreement Gilead	Common Stock	Common Stock Purchase Agreement Gilead	Additional Paid-In Capital	Additional Paid-In Capital Purchase Agreement Gilead	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2020	$ 502,304		$ 6		$ 830,438		$ (328,184)	$ 44
Balance, shares at Dec. 31, 2020			63,691,901
Issuance of common stock		$ 220,296		$ 1		$ 220,295
Issuance of common stock, shares				5,650,000
Issuance of common stock upon exercise of stock options and vesting of restricted stock	1,885				1,885
Issuance of common stock upon exercise of stock options and vesting of restricted stock, shares			200,828
Vesting of early exercised stock options	183				183
Vesting of early exercised stock options, shares			54,039
Stock-based compensation	12,761				12,761
Other comprehensive loss	(46)							(46)
Net loss	(72,593)						(72,593)
Balance at Mar. 31, 2021	664,790		$ 7		1,065,562		(400,777)	(2)
Balance, shares at Mar. 31, 2021			69,596,768
Balance at Dec. 31, 2021	$ 841,450		$ 7		1,118,058		(275,354)	(1,261)
Balance, shares at Dec. 31, 2021	70,781,736		70,771,790
Issuance of common stock upon exercise of stock options and vesting of restricted stock	$ 9,928				9,928
Issuance of common stock upon exercise of stock options and vesting of restricted stock, shares			840,577
Vesting of early exercised stock options	52				52
Vesting of early exercised stock options, shares			9,946
Stock-based compensation	16,541				16,541
Other comprehensive loss	(3,399)							(3,399)
Net loss	(67,993)						(67,993)
Balance at Mar. 31, 2022	$ 796,579		$ 7		$ 1,144,579		$ (343,347)	$ (4,660)
Balance, shares at Mar. 31, 2022	71,622,313		71,622,313