Note 1 - Significant Accounting Policies - Assets and Liabilities at Fair Value on a Recurring Basis (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restricted Cash	$ 100,000	$ 100,000
Total	3,963,000	4,881,000	$ 4,798,000
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Cash	3,863,000	4,781,000
Unrealized Gains
Unrealized Losses
Restricted Cash	100,000	100,000
Total	$ 3,963,000	$ 4,881,000