Note 3 - Income Taxes - Reconciliation of the Statutory Federal Income Tax Rate to Qualstar's Effective Rate (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Federal tax rate	21.00%	34.00%
State income taxes, net of federal income tax benefit	6.60%	13.60%
Foreign income taxes, net of federal income tax benefit		6.40%
Engineering credits		3.40%
Tax effect of change in federal tax rate (from 34% to 21%)		649.50%
Valuation allowance	(26.60%)	(712.00%)
Other	(0.60%)	7.80%
Effective federal income tax rate	0.40%	2.70%