Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 183,099	$ 82,253
Marketable securities	17,509	54,407
Accounts receivable, net	21,524	37,115
Inventories	19,392	16,529
Prepaid expenses and other current assets	5,043	5,371
Total current assets	246,567	195,675
Property and equipment, net	17,795	13,662
Right-of-use assets	7,414	8,223
Total assets	271,776	217,560
Current liabilities
Accounts payable	7,886	15,258
Accrued expenses and other current liabilities	15,410	19,610
Deferred revenue	5,000
Operating lease liabilities	1,422	1,351
Current portion of long-term debt	7,639
Total current liabilities	37,357	36,219
Long-term operating lease liability, net	6,790	7,609
Long-term debt, net	52,829	40,176
2024 convertible notes, net	157,990	153,413
Other long-term liabilities	295	251
Total liabilities	255,261	237,668
Commitments and contingencies
Preferred stock, $0.001 par value; 10,000,000 shares authorized at June 30, 2020 and December 31, 2019 and 0 shares issued and outstanding at June 30, 2020 and December 31, 2019	0	0
Stockholders' equity
Common stock, $0.001 par value; 100,000,000 shares authorized; 49,270,392 and 38,361,476 shares issued and outstanding, at June 30, 2020 and December 31, 2019, respectively	49	38
Additional paid-in capital	754,483	648,391
Accumulated other comprehensive income	3	62
Accumulated deficit	(738,020)	(668,599)
Total stockholders' equity (deficit)	16,515	(20,108)
Total liabilities and stockholders' equity	$ 271,776	$ 217,560