CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (42,825)	$ (54,376)	$ (59,857)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,984	3,148	3,109
Stock-based compensation	24,456	23,571	18,029
Non-cash operating lease cost	1,575	1,422	1,435
Impairment (unrealized gain) in private company investment	2,183	239	(422)
Net loss (gain) on sale of available-for-sale securities	108	(21)	234
Unrealized gain on investments	(564)	(267)
Impairment of long-lived assets			274
Non-cash interest expense	609	591	478
Foreign currency remeasurement loss (gain)	1,911	511	(887)
Changes in operating assets and liabilities:
Accounts receivable	(9,200)	(4,215)	(4,125)
Inventories	(1,768)	(19,610)	(4,030)
Prepaid and other assets	1,168	2,738	(597)
Accounts payable	(4,905)	12,204	1,984
Accrued liabilities and other non-current liabilities	(1,263)	47	2,557
Deferred product revenue	(84)	96	7
Net cash used in operating activities	(25,615)	(33,922)	(41,811)
Investing activities
Capital expenditures	(2,000)	(910)	(1,615)
Purchases of investments	(29,640)	(52,066)	(98,793)
Proceeds from maturities and sale of investments	40,104	65,664	50,850
Net cash provided by (used in) investing activities	8,464	12,688	(49,558)
Financing activities
Net proceeds from equity incentives	4,084	9,370	11,750
Net (costs) proceeds from public offerings	(104)	2,743	76,534
Net proceeds on revolving line of credit	212	6,181	3,499
Proceeds from loans		15,000
Contribution from noncontrolling interest		1,000
Net cash provided by financing activities	4,192	34,294	91,783
Effect of exchange rates on cash, cash equivalents, and restricted cash	(727)	(919)	1,068
Net (decrease) increase in cash, cash equivalents and restricted cash	(13,686)	12,141	1,482
Cash, cash equivalents and restricted cash, beginning of period	51,044	38,903	37,421
Cash, cash equivalents and restricted cash, end of period	37,358	51,044	38,903
Supplemental disclosure of cash flow information:
Cash paid for interest	5,100	4,181	3,269
Cash paid for income taxes	$ 270	$ 278	$ 265