Note 5 - Revenue Recognition (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Accounts Receivable, Allowance for Credit Loss, Ending Balance	$ 16,895		$ 16,895		$ 16,895
Revenue Benchmark [Member] \| Geographic Concentration Risk [Member] \| Non-US [Member] \| ASI [Member]
Concentration Risk, Percentage	70.00%	77.00%	75.00%	73.00%
Revenue Benchmark [Member] \| Geographic Concentration Risk [Member] \| Non-US [Member] \| Personal Care [Member]
Concentration Risk, Percentage	21.00%	17.00%	20.00%	17.00%
Revenue Benchmark [Member] \| Geographic Concentration Risk [Member] \| CHINA \| ASI [Member]
Concentration Risk, Percentage	54.00%	62.00%	52.00%	54.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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