Note 5 - Recent Accounting Pronouncements (Details Textual) - USD ($)	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	[1]
Assets, Total	$ 37,397,000		$ 34,255,000
Liabilities, Total	$ 4,811,000		$ 2,061,000
Accounting Standards Update 2016-02 [Member]
Assets, Total		$ 3,455,000
Liabilities, Total		$ 3,455,000

[1] The condensed consolidated balance sheet as of December 31, 2018 has been prepared using information from the audited consolidated balance sheet as of that date.