Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	Jun. 30, 2019	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Lessee, Operating Lease, Discount Rate	12.00%		12.00%
Accumulated Development Costs	$ 7,256,571	$ 6,971,267		$ 6,716,810	$ 6,304,540	$ 6,039,095	$ 5,768,476

Discount rate used by lessee to determine present value of operating lease payments.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant