Note 4 - Investments - Investment in Common Stock Warrants (Details) - USD ($)		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014
Warrant [Member]
Beginning balance			$ 350,000
Gain on investment in common stock warrants			30,000
Fair value of warrants exercised			$ (380,000)
Ending balance
Beginning balance	[1]	$ 2,840,000
Gain on investment in common stock warrants			$ (30,000)
Ending balance		$ 826,000

[1] The condensed consolidated balance sheet as of December 31, 2014 has been prepared using information from the audited consolidated balance sheet as of that date.