Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Allowances for doubtful accounts receivable	$ 170	$ 221
Related-party notes payable, discount & issuance costs	0	0
Notes payable, discount & issuance costs	$ 312	$ 442
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	5,500	5,500
Preferred stock, shares outstanding	1,370	5,500
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	25,003,420	14,268,765
Common stock, shares outstanding	25,003,420	14,268,765