Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss	$ (176,693)	$ (154,637)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	35,364	45,206
Depreciation and amortization	7,150	7,367
Net amortization/accretion on investment securities	(566)	2,240
Non-cash rent expense	357	1,640
Share of loss from equity method investment	2,907	2,309
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,365	(8,515)
Other long-term assets	(55)	(2,803)
Accounts payable	(3,233)	917
Accrued and other current liabilities	5,610	(3,334)
Deferred revenue	(656)	413
Other long-term liabilities	(46)	(1,571)
Net cash used in operating activities	(128,496)	(110,768)
Cash flows from investing activities:
Purchases of property and equipment	(1,323)	(3,276)
Proceeds from sales of investments	5,623	0
Proceeds from maturities of investments	296,309	185,797
Purchase of investments	(170,514)	(150,864)
Net cash provided by investing activities	130,095	31,657
Cash flows from financing activities:
Proceeds from issuance of common stock from ATM offering, net of commissions and issuance costs	87,918	0
Proceeds from issuance of common stock upon exercise of stock options	1,606	308
Proceeds from issuance of common stock under the employee stock purchase plan	1,731	1,530
Net cash provided by financing activities	91,255	1,838
Net change in cash and cash equivalents and restricted cash	92,854	(77,273)
Cash and cash equivalents and restricted cash — beginning of period	72,196	183,606
Cash and cash equivalents and restricted cash — end of period	165,050	106,333
Non-cash investing activities:
Right-of-use asset obtained in exchange for lease liability	0	31,361
Supplemental disclosure:
Cash paid for amounts included in the measurement of lease liabilities	(5,989)	(3,983)
Cash received for amounts related to tenant improvement allowances	$ 0	$ 325