Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (82,470)	$ (81,423)	$ (69,592)	$ (74,930)	$ (163,893)	$ (144,522)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization					3,052	2,908
Amortization (accretion) of premium (discount) on marketable securities					88	112
Non-cash interest expense					1,541	476
Amortization of operating lease right-of-use assets					1,518	1,301
Stock-based compensation					38,984	41,184
Changes in operating assets and liabilities:
Accounts receivables					(965)	(2,044)
Inventories					(6,806)	(6,841)
Prepaid expenses and other assets, current					2,977	(7,121)
Other assets, non-current					(394)	0
Accounts payable					(6,844)	(9,730)
Accrued liabilities					13,971	7,683
Accrued compensation					(2,525)	(4,655)
Operating lease liabilities					(2,735)	(2,328)
Other liabilities, noncurrent					5,870	0
Net cash used in operating activities					(116,161)	(123,577)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment					(636)	(1,920)
Purchases of marketable securities					(386,025)	0
Maturities of marketable securities					29,500	47,670
Net cash provided by (used in) investing activities					(357,161)	45,750
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock in settlement of employee stock purchase plan and exercise of stock options					2,799	4,083
Proceeds from issuance of common stock upon at-the-market offering, net of issuance cost					48,495	0
Taxes paid related to net share settlement of equity awards					(1,095)	(1,962)
Payments of debt issuance costs					0	(49)
Net cash provided by financing activities					50,199	2,072
Effect of exchange rate changes on cash and cash equivalents					(446)	259
Net decrease in cash, cash equivalents and restricted cash					(423,569)	(75,496)
Cash, cash equivalents and restricted cash at beginning of period		$ 687,153		$ 497,202	687,153	497,202	$ 497,202
Cash, cash equivalents and restricted cash at end of period	263,584		421,706		263,584	421,706	687,153
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest					14,511	6,788
Cash paid for income taxes					80	0
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Accrued issuance costs					0	(26)
Accrued purchase of property and equipment					7	(36)
RECONCILIATION OF CASH, CASH EQUIVALENTS, AND RESTRICTED CASH TO THE CONDENSED CONSOLIDATED BALANCE SHEETS
Cash and cash equivalents	261,152		419,311		261,152	419,311	$ 684,717
Restricted cash	2,432		2,395		2,432	2,395
Total cash and cash equivalents and restricted cash	$ 263,584		$ 421,706		$ 263,584	$ 421,706