Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net loss	$ (104,234)	$ (88,208)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	18,605	12,826
Depreciation and amortization expense	3,784	3,367
Amortization (accretion) of premium (discount) on marketable securities, net	(984)	514
Loss on sale of property and equipment	28	223
Loss on impairment of leasehold improvements	5,395	0
Changes in operating assets and liabilities:
Tenant receivable	(395)	0
Prepaid expenses and other current assets	(4,939)	504
Operating lease right-of-use assets	4,017	2,157
Other noncurrent assets	(1,151)	(133)
Accounts payable	(444)	253
Accrued expenses and other current liabilities	(1,663)	523
Operating lease liability	2,536	(3,045)
Net cash used in operating activities	(79,445)	(71,019)
Cash flows from investing activities:
Purchases of property and equipment	(8,119)	(3,123)
Proceeds from sale of property and equipment		105
Purchases of marketable securities	(221,000)	0
Maturities of marketable securities	55,000	188,900
Net cash (used in) provided by investing activities	(174,119)	185,882
Cash flows from financing activities:
Proceeds from public offering of common stock, net of underwriting discounts and commissions	0	211,876
Payment of offering costs	(50)	(942)
Proceeds from issuance of common stock from public ATM offering, net of commissions and offering costs	12,360	0
Proceeds from exercise of stock options and other types of equity, net	990	3,302
Payments of employee taxes for common stock withheld upon issuance	(394)	0
Net cash provided by financing activities	12,906	214,236
Net increase in cash, cash equivalents and restricted cash	(240,658)	329,099
Cash, cash equivalents and restricted cash at beginning of period	380,837	64,940
Cash, cash equivalents and restricted cash at end of period	140,179	394,039
Supplemental disclosure of noncash investing and financing information:
Purchases of property and equipment included in accounts payable and accrued expenses	165	249
Unrealized Loss on Marketable Securities	(302)	(8)
Offering costs included in accounts payable and accrued expenses	$ 0	$ 80