Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accounts receivable allowance, net	$ 234	$ 235
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	101,382,448	53,178,462
Common stock, shares outstanding (in shares)	101,382,447	53,178,461
Treasury stock (in shares)	1	1
Series 4 Convertible Preferred Stock
Preferred stock, shares authorized (in shares)	10,415	10,415
Preferred stock, shares issued (in shares)	1	1
Series 5 Convertible Preferred Stock
Preferred stock, shares authorized (in shares)	12,000	12,000
Preferred stock, shares issued (in shares)	126	126
Preferred stock, shares outstanding (in shares)		126
Common stock, shares outstanding (in shares)	126