Note 5 - Income Taxes - Income Taxes Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Provision for income taxes at federal statutory rate	$ 747	$ 1,120
Provision for income taxes at federal statutory rate, rate	34.00%	34.00%
State income taxes, net of federal benefit	$ (45)	$ 30
State income taxes, net of federal benefit, rate	(2.10%)	0.90%
Permanent differences	$ 68	$ 28
Permanent differences, rate	3.10%	0.80%
Federal Research and Development Credit	$ (89)	$ (192)
Federal Research and Development Credit, rate	(4.00%)	(5.80%)
Return to provision (benefit)		$ (51)
Return to provision (benefit), rate		(1.50%)
Foreign tax rate differential (benefit)	$ (242)	$ (60)
Foreign tax rate differential (benefit), rate	(11.00%)	(1.80%)
Other (benefit)	$ 2	$ (56)
Other (benefit), rate	0.10%	(1.70%)
Net expense	$ 441	$ 819
Net expense, rate	20.10%	24.90%