Note 4 - Investments (Details Textual) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Proceeds from Sale and Maturity of Marketable Securities	$ 0		$ 440,000
Available-for-sale Securities, Current	2,307,000		2,840,000	[1]
Marketable Securities, Realized Gain (Loss)			379,000
Marketable Securities Realized Gain (Loss), Net of Tax			245,000
Marketable Securities, Unrealized Gain (Loss)	(328,000)	442,000
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	$ (205,000)	$ 155,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	167,500

[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.