Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Allowances for doubtful accounts receivable	$ 221	$ 197
Related-party notes payable, discount & issuance costs	0	619
Notes payable, discount & issuance costs	$ 442	$ 619
Preferred stock, par value	$ 0.001
Preferred stock, shares authorized	5,000,000
Preferred stock, shares issued	5,500
Preferred stock, shares outstanding	5,500
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	14,268,765	12,297,954
Common stock, shares outstanding	14,268,765	12,297,954