Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (110,489)	$ (70,358)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2,668	2,086
Stock-based compensation expense	22,785	11,113
Purchase net discount (premium) on marketable securities	1,651	(662)
Net amortization of premiums on marketable securities	194	332
Non-cash lease expense	2,090	1,507
Changes in assets and liabilities:
Prepaid expenses and other current assets	2,892	(1,573)
Other non-current assets	36	(283)
Accounts payable	(2,051)	685
Accrued liabilities	4,957	3,323
Lease liabilities, net	(1,949)	(1,446)
Deferred Revenue	149,634
Net cash provided by (used in) operating activities	72,418	(55,276)
Cash flows from investing activities:
Purchase of property, plant and equipment	(4,800)	(9,235)
Purchases of marketable securities	(282,512)	(48,000)
Proceeds from maturities of marketable securities	84,227	114,569
Proceeds from the sales of marketable securities	0	2,997
Net cash (used in) provided by investing activities	(203,085)	60,331
Cash flows from financing activities:
Payment of employee taxes and exercise costs for shares withheld		(1,015)
Proceeds from exercise of stock options	139	524
Proceeds from purchases under the employee stock purchase plan	477	405
Proceeds from issuance of common stock in public offering, net of offering costs	217,987
Net cash provided by (used in) financing activities	218,603	(86)
Net increase in cash, cash equivalents, and restricted cash	87,936	4,969
Beginning of period	134,035	241,080
End of period	221,971	246,049
Cash and Cash Equivalents, at Carrying Value	221,274	246,049
Restricted Cash and Cash Equivalents	697
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	221,971	246,049
Supplemental disclosure of non-cash investing and financing activities:
Right-of-use assets recognized in exchange for lease obligations	2,315	1,844
Unpaid amounts related to purchase of property, plant and equipment	$ 1,156	$ 814