Note 11 - Blockchain Software Application Platform Development Costs (Details Textual) $ in Thousands, ¥ in Millions	Sep. 30, 2021 USD ($)	Dec. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2018 CNY (¥)
Capitalized Cost of Blockchain Technology Based Applications Development Costs	$ 4,410
Contract to Develop Blockchain Technology Based Applications [Member]
Application Development Contracts, Contract Amount		$ 4,960	$ 4,500
Contract to Develop Social Network Based Applications [Member]
Application Development Contracts, Contract Amount			$ 460	¥ 3