Consolidated Statements of Cash Flows - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net loss	$ (229,743)	$ (124,827)	$ (128,154)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	8,613	7,730	7,501
Non-cash lease expense	7,834	7,748
Impairment of assets		1,671	1,544
Stock-based compensation	50,171	28,624	14,198
Inventory reserve adjustments	(163)	321	265
Premium amortization and discount accretion on investment securities	5,761	945	238
(Gain) loss on investments	(105)	(16)	43
Loss on sale of property and equipment			(12)
Loss from changes in fair value of warrants			4,118
Interest accrued for borrowings and claims related settlement			2,172
Amortization of debt discount and issuance cost	149	457	391
Other non-cash benefits	(149)	(51)
Gain on disposal of business		(14,388)
Provision for credit losses	1,354	1,141	(41)
Loss on Debt Extinguishment	5,848
Accretion of Convertible Note	7,048
Changes in operating assets and liabilities
Accounts receivable	(25,831)	2,418	(18,093)
Inventory	(7,474)	917	(4,900)
Prepaid expenses and other current assets	(23,386)	(13,956)	2,643
Other assets	(60)	(9,099)	335
Accounts payable	(118)	(6,262)	3,781
Accrued compensation	14,284	3,419	3,069
Other accrued liabilities	10,340	8,606	(1,820)
Deferred revenue	(6,895)	40,848	42,769
Deferred rent, net of current portion			(628)
Other long-term liabilities	10	310
Net cash used in operating activities	(182,512)	(63,444)	(70,581)
Investing activities
Purchases of investments	(685,239)	(446,626)	(170,268)
Proceeds from sale of investments	30,067	1,666	37,387
Proceeds from maturity of investments	343,315	173,900	131,600
Net proceeds from disposal of business		9,675
Purchases of property and equipment, net	(19,604)	(4,968)	(3,880)
Net cash used in investing activities	(331,461)	(266,353)	(5,161)
Financing activities
Proceeds from exercise of stock options	23,524	13,041	13,331
Proceeds from issuance of common stock under employee stock purchase plan	7,114	4,323	3,617
Proceeds from Convertible Note, net of issuance costs	278,316
Loan payment	(78,757)
Proceeds from public offering, net of issuance costs	270,650	323,410	96,777
Net cash provided by financing activities	500,847	340,774	113,725
Net increase (decrease) in cash, cash equivalents and restricted cash	(13,126)	10,977	37,983
Cash, cash equivalents and restricted cash, beginning of period	61,981	51,004	13,021
Cash, cash equivalents and restricted cash, end of period	48,855	61,981	51,004
Supplemental disclosure of cash flow information:
Cash paid for income taxes	67	2,154	332
Cash paid for interest	3,296	12,455	7,914
Non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accruals	$ 2,781	$ 3,706	$ 268
Issuance of common stock for exercise of warrants			6,762