CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Accounts receivable, allowances for bad debts and customer credits	$ 553	$ 566
Stockholders' equity:
Common stock, par value	$ 0.001	$ 0.001
Common stock, authorized	55,000,000	55,000,000
Common stock, issued	13,146,831	12,960,450
Common stock, outstanding	13,146,831	12,960,450
Preferred Class A [Member]
Stockholders' equity:
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, authorized	11,445,187	11,445,187
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0