CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, allowances	$ 306	$ 307
Debt instrument unamortized discount and debt issuance costs, current	404	181
Debt instrument unamortized discount and debt issuance costs, non-current	$ 582	$ 221
Preferred stock, par value	$ 0.001
Preferred stock, shares authorized	10,000,000
Preferred stock, outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	15,341,000	11,836,000
Common stock, shares outstanding	14,435,000	11,109,000
Treasury stock, shares	905,000	727,000
Series B Preferred Stock
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, issued	3,000,000	0
Preferred stock, outstanding	3,000,000	0