Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 7,147	$ 10,910
Available-for-sale securities	9,184	0
Trade accounts receivable (net of allowance for doubtful accounts of $50 in 2017 and 2016)	5,524	3,448
Inventories, net	14,358	13,999
Prepaid expenses and other current assets	772	1,410
Total current assets	36,985	29,767
Property, plant and equipment, net	2,201	2,486
Available-for-sale securities	0	6,472
Deferred tax assets, net	3,317	3,418
Other assets	298	401
Total assets	42,801	42,544
Current liabilities:
Accounts payable	5,971	1,973
Accrued compensation and related taxes	1,364	2,193
Accrued warranty expense	1,389	650
Accrued other expenses and other current liabilities	1,159	169
Dividends payable	273	1,235
Deferred revenue	157	142
Total current liabilities	10,313	6,362
Deferred revenue	481	408
Total liabilities	10,794	6,770
Commitments and contingencies
Stockholders' equity:
Preferred stock; $1.00 par value; 1,000,000 authorized shares: none issued or outstanding	0	0
Common stock; $.60 par value; 20,000,000 authorized shares: 13,844,584 and 13,754,749 issued and outstanding shares at December 31, 2017 and 2016, respectively	8,307	8,253
Additional paid-in capital	25,642	25,382
Retained earnings	(5,450)	240
Accumulated other comprehensive income	4,318	2,061
Treasury stock, at cost, 192,094 and 30,422 shares at December 31, 2017 and 2016, respectively	(810)	(162)
Total stockholders' equity	32,007	35,774
Total liabilities and stockholders' equity	$ 42,801	$ 42,544