Note 5 - Investment Securities Available for Sale (Details Textual) - USD ($)		3 Months Ended		9 Months Ended		12 Months Ended
	Nov. 28, 2016	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2016
Available-for-sale Securities, Gross Unrealized Loss				$ 139,000		$ 557,000
Marketable Securities				6,073,000		9,656,000
Available-for-sale Securities, Amortized Cost Basis				5,598,000		9,791,000
Available-for-sale Securities, Gross Unrealized Gain				614,000		422,000
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net				1,502,239
Available-for-sale Securities, Gross Realized Gains				583,000	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value				613,000		5,903,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss				139,000		163,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value				0		4,711,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss						$ 395,000
Insignia [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.70
Insignia [Member]
Available-for-sale Securities, Gross Unrealized Gain				430,000
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net		$ 1,502,000	$ 0	1,502,000	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		$ 3,604,000		$ 4,034,000