Note 1 - Basis of Presentation (Details Textual)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2019
Period for Creating Allowance for Doubtful Accounts	120 days
Scenario, Forecast [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncement Effect, Lease Obligation Asset and Liability, Percent		1.00%