CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities
Net loss	$ (31,337)	$ (36,354)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,488	1,112
Stock-based compensation	8,460	6,017
Non-cash operating lease cost	619	796
Loss on sale of available-for-sale securities	261
Loss on disposal of property and equipment		14
Non-cash interest expense	237	247
Changes in operating assets and liabilities:
Accounts receivable	(742)	(4,680)
Inventories	962	(3,977)
Other assets	140	1,817
Accounts payable	(3,186)	3,229
Accrued liabilities and other non-current liabilities	(4,644)	(3,410)
Manufacturing and development obligations		(38)
Deferred product revenue	136	167
Net cash used in operating activities	(27,606)	(35,060)
Investing activities
Capital expenditures	(907)	(6,516)
Purchases of investments	(76,871)	(27,728)
Proceeds from maturities and sale of investments	25,998	43,000
Net cash (used in) provided by investing activities	(51,780)	8,756
Financing activities
Net proceeds from equity incentives	2,797	1,270
Net proceeds from public offerings	76,595	6,783
Net (payment on) proceeds from revolving line of credit	(67)	4,496
Proceeds from loans		39,433
Repayment of debt		(31,045)
Net cash provided by financing activities	79,325	20,937
Net decrease in cash, cash equivalents and restricted cash	(61)	(5,367)
Cash, cash equivalents and restricted cash, beginning of period	37,421	31,587
Cash, cash equivalents and restricted cash, end of period	$ 37,360	$ 26,220