Note 11 - Blockchain Software Application Platform Development Costs (Details Textual) $ in Thousands, ¥ in Millions	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2018 CNY (¥)	Feb. 28, 2018 USD ($)
Capitalized Cost of Blockchain Technology Based Applications Development Costs	$ 4,190	$ 3,880
Contract to Develop Blockchain Technology Based Applications [Member]
Application Development Contracts, Contract Amount			$ 4,940			$ 4,500
Contract to Develop Social Network Based Applications [Member]
Application Development Contracts, Contract Amount				$ 440	¥ 3