Note 4 - Marketable Securities (Details Textual) - USD ($)	3 Months Ended				6 Months Ended		12 Months Ended
	Sep. 30, 2015	Mar. 31, 2015		Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Mar. 31, 2015
Insignia [Member]
Available-for-sale Securities, Gross Unrealized Loss					$ 920,000
Available-for-sale Securities, Noncurrent	$ 5,056,000				5,056,000
Marketable Securities, Realized Gain (Loss), Excluding Other than Temporary Impairments	0			$ 0	0	$ 8,410
Marketable Securities	6,276,000				6,276,000
Available-for-sale Securities, Amortized Cost Basis	7,353,000	$ 5,490,000			7,353,000		$ 5,490,000
Available-for-sale Securities, Gross Unrealized Gain					48,000		0
Available-for-sale Securities, Gross Unrealized Loss					1,125,000		211,000
Marketable Securities, Current	2,139,815	5,278,752			2,139,815		5,278,752
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	4,888,000	4,168,000			4,888,000		4,168,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss		176,000			1,052,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		35,000			73,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,216,000	$ 1,111,000			1,216,000		$ 1,111,000
Available-for-sale Securities, Noncurrent	$ 4,136,127		[1]		$ 4,136,127			[1]

[1] Derived from audited financial statements