Note 9 - Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018		Mar. 31, 2017
Income tax expense at federal statutory rate [21%-2018; 34%-2017]	$ 173,587	[1]	$ 717,600
State taxes	9,000		6,455
Change in other accruals	(75)		5,639
Difference between tax and book depreciation	33,037		54,390
FAS 123R employee compensation	44,860		(36,032)
Domestic production activities deduction			(50,320)
Net operating loss			(13,600)
Federal research and development credit	(12,639)
Income tax expense	$ 247,770		$ 684,132

[1] The Company's foreign entity, CVD Tantaline ApS, has incurred losses since its inception in December 2016, which would provide a deferred tax asset at March 31, 2018, based on the standard corporate tax rate of 22% in Denmark. However, sufficient uncertainty exists as to the realizability of these assets such that a full valuation allowance is necessary.