CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities:
Net loss	$ (184,586)	$ (188,386)
Non-cash adjustments reconciling net loss to operating cash flows
Change in fair value on long-term investment	112	5,077
Depreciation and amortization expense	1,075	629
Amortization of premium and accretion of discounts on investments	(5,168)	982
Share-based compensation expense	46,961	42,905
Changes in operating assets and liabilities:
Accounts receivable, net	(5,362)	0
Inventory	(829)	0
Other current assets	(5,741)	0
Other long-term assets	(1,790)	(1,584)
Right-of-use asset	339	451
Lease liability	(376)	1,431
Accounts payable, accrued liabilities and other liabilities	(34,817)	(21,974)
Cash flows used in operating activities	(190,182)	(160,469)
Investing activities:
Purchases of short-term investments	(126,708)	(212,545)
Sales and maturities of short-term investments	322,128	263,240
Purchases of property and equipment	(269)	(1,140)
Cash flows provided by investing activities	195,151	49,555
Financing activities:
Proceeds from issuance of common stock under equity incentive plans	1,727	2,527
Cash flows provided by financing activities	1,727	2,527
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(31)	0
Increase (decrease) in cash, cash equivalents and restricted cash	6,665	(108,387)
Cash, cash equivalents and restricted cash, beginning of period	235,880	413,703
Cash, cash equivalents and restricted cash, end of period	242,545	305,316
Reconciliation of cash, cash equivalents and restricted cash, end of period:
Cash and cash equivalents	241,925	304,696
Restricted cash included in other long-term assets	620	620
Total cash, cash equivalents and restricted cash	242,545	305,316
Supplemental disclosures of non-cash investing activities:
Accrued capital expenditures	$ 193	$ 842