Note 11 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating loss (state and foreign)	$ 444	$ 71
Tax credit carryforwards	206
Inventories	185	182
Accrued vacation pay and stock-based compensation	156	161
Depreciation of property and equipment	97	580
Allowance for doubtful accounts	47	55
Accrued warranty	20	9
Acquisition costs	15	28
Intangibles		311
Other	15	7
Total	1,185	1,404
Valuation allowance	(370)
Deferred tax assets	815	1,404
Deferred tax liabilities:
Net intangible assets	(3,421)	(212)
Unremitted earnings of foreign subsidiaries		(82)
Deferred tax liabilities	(3,421)	(294)
Net deferred tax assets (liabilities)	(2,606)	(1,110)
Net deferred tax assets (liabilities)	$ 2,606	$ 1,110