CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net loss	$ (54,376)	$ (59,857)	$ (71,244)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,148	3,109	2,403
Stock-based compensation	23,571	18,029	13,312
Non-cash operating lease cost	1,422	1,435	1,566
Changes in valuation of warrant investment	(148)	(422)
Net (gain) loss on sale of available-for-sale securities	(21)	234
Loss on disposal of property and equipment			15
Impairment of long-lived assets	387	274
Unrealized gain on investments	(267)
Non-cash interest expense	1,248	478	386
Foreign currency remeasurement loss (gain)	511	(887)	367
Changes in operating assets and liabilities:
Accounts receivable	(4,215)	(4,125)	(8,075)
Inventories	(19,610)	(4,030)	(6,043)
Other assets	2,738	(597)	1,802
Accounts payable	12,204	1,984	4,939
Accrued liabilities and other non-current liabilities	(610)	2,557	1,335
Manufacturing and development obligations			(6,334)
Deferred product revenue	96	7	72
Net cash used in operating activities	(33,922)	(41,811)	(65,499)
Investing activities
Capital expenditures	(910)	(1,615)	(8,935)
Purchases of investments	(52,066)	(98,793)	(43,907)
Proceeds from maturities and sale of investments	65,664	50,850	81,027
Net cash provided by (used in) investing activities	12,688	(49,558)	28,185
Financing activities
Net proceeds from equity incentives	9,370	11,750	3,210
Net proceeds from public offering	2,743	76,534	26,931
Net proceeds on revolving line of credit	6,181	3,499	5,017
Proceeds from loans	15,000		39,433
Repayment of loans			(31,104)
Contribution from noncontrolling interest	1,000
Net cash provided by financing activities	34,294	91,783	43,487
Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	(919)	1,068	(339)
Net increase in cash, cash equivalents and restricted cash	12,141	1,482	5,834
Cash, cash equivalents and restricted cash, beginning of period	38,903	37,421	31,587
Cash, cash equivalents and restricted cash, end of period	51,044	38,903	37,421
Supplemental disclosure of cash flow information:
Cash paid for interest	4,181	3,269	3,077
Cash paid for income taxes	$ 278	$ 265	229
Non-cash investing activities:
Non-cash leasehold improvements			$ 2,949