Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (471,716)	$ (229,743)	$ (124,827)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	11,254	8,613	7,730
Expensed in-process research and development	35,604
Non-cash lease expense	10,926	7,834	7,748
Impairment of assets	0		1,671
Stock-based compensation	115,219	50,171	28,624
Inventory reserve adjustments	628	(163)	321
Premium amortization and discount accretion on investment securities	7,814	5,761	945
Loss on investments	(46)	(105)	(16)
Unrealized losses on investment securities	(11)
Amortization of debt discount and issuance cost	1,227	149	457
Other non-cash benefits (charges)	94	(149)	(51)
Gain on disposal of business			(14,388)
Provision for credit losses	(156)	1,354	1,141
Loss on debt extinguishment		5,848
Accretion of Convertible Note		7,048
Changes in operating assets and liabilities:
Accounts receivable	(43,353)	(25,831)	2,418
Inventory	(7,506)	(7,474)	917
Prepaid expenses and other current assets	(10,545)	(23,386)	(13,956)
Other assets	(2,933)	(60)	(9,099)
Accounts payable	19,222	(118)	(6,262)
Accrued compensation	10,569	14,284	3,419
Other accrued liabilities	32,682	10,340	8,606
Deferred revenue	(44,209)	(6,895)	40,848
Other long-term liabilities		10	310
Net cash used in operating activities	(335,236)	(182,512)	(63,444)
Investing activities:
Purchases of investments	(876,095)	(685,239)	(446,626)
Proceeds from sale of investments	187,580	30,067	1,666
Proceeds from maturity of investments	532,910	343,315	173,900
Net proceeds from disposal of business			9,675
Purchases of property and equipment, net	(41,030)	(19,604)	(4,968)
Cash paid for acquisition of an asset	(8,558)
Net cash used in investing activities	(205,193)	(331,461)	(266,353)
Financing activities:
Proceeds from exercise of stock options	11,816	23,524	13,041
Proceeds from issuance of common stock under employee stock purchase plan	13,550	7,114	4,323
Proceeds from Convertible Note, net of issuance costs		278,316
Loan payment		(78,757)
Proceeds from public offering, net of issuance costs	550,822	270,650	323,410
Net cash provided by financing activities	576,188	500,847	340,774
Net increase (decrease) in cash equivalents and restricted cash	35,759	(13,126)	10,977
Beginning - cash equivalents & restricted cash	48,855	61,981	51,004
Ending - cash equivalents and restricted cash	84,614	48,855	61,981
Supplemental disclosure of cash flow information:
Cash paid for income taxes	283	67	2,154
Cash paid for interest	7,077	3,296	12,455
Non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accruals	$ 5,173	$ 2,781	$ 3,706