Note 5 - Investment Securities Available for Sale (Details Textual) - USD ($)	3 Months Ended				9 Months Ended	12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016		Jun. 30, 2015	Dec. 31, 2014	Mar. 31, 2016
Marketable Securities	$ 8,384,000	$ 9,656,000				$ 9,656,000
Available-for-sale Securities, Amortized Cost Basis	9,643,000	9,791,000				9,791,000
Available-for-sale Securities, Gross Unrealized Gain	413,000	422,000
Available-for-sale Securities, Gross Unrealized Loss	1,673,000	557,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1,182,000	5,903,000				5,903,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	170,000					163,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	3,604,000	4,711,000				4,711,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	1,502,000					395,000
Available-for-sale Securities, Gross Realized Gains	144,000			$ 0
Available-for-sale Securities, Gross Realized Losses					$ 0
Available-for-sale Securities, Noncurrent	3,603,764	$ 4,711,343	[1]			$ 4,711,343	[1]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	1,502,239
Insignia [Member]
Available-for-sale Securities, Gross Unrealized Loss	1,502,000
Available-for-sale Securities, Noncurrent	5,106,000
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	$ 1,502,000			$ 0

[1] Derived from audited financial statements