CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 34,900	$ 34,986
Short-term investments	101,570	50,732
Accounts receivable	17,624	16,882
Inventories	18,425	19,490
Prepaid and other current assets	6,452	6,018
Total current assets	178,971	128,108
Non-current assets:
Property and equipment, net	14,534	14,898
Goodwill	1,316	1,316
Operating lease right-of-use assets	13,768	14,122
Intangible assets, net	31	132
Restricted cash	2,460	2,435
Other assets	4,414	4,524
Total assets	215,494	165,535
Current liabilities:
Accounts payable	18,831	22,185
Accrued liabilities	16,865	20,951
Debt – current	4,950	5,017
Operating lease liabilities – current	1,793	1,613
Deferred product revenue	706	570
Total current liabilities	43,145	50,336
Non-current liabilities:
Debt – non-current	39,500	39,414
Operating lease liabilities – non-current	17,611	18,406
Other non-current liabilities	713	327
Total liabilities	100,969	108,483
Commitments and contingencies
Stockholders' equity:
Common stock	166	144
Additional paid-in capital	994,682	906,905
Accumulated other comprehensive income	1,125	114
Accumulated deficit	(881,448)	(850,111)
Total stockholders' equity	114,525	57,052
Total liabilities and stockholders' equity	$ 215,494	$ 165,535