Note 4 - Marketable Securities and Investments in Available-for-Sale Securities (Details Textual) - USD ($)	3 Months Ended			6 Months Ended	12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Mar. 31, 2015
Insignia [Member]
Available-for-sale Securities, Gross Unrealized Loss				$ 598,000
Available-for-sale Securities, Noncurrent	$ 4,966,000			4,966,000
Marketable Securities	5,910,000			5,910,000
Available-for-sale Securities, Amortized Cost Basis	6,560,000	$ 5,490,000		6,560,000	$ 5,490,000
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	35,000			35,000
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	685,000			685,000
Marketable Securities, Current	1,541,910	5,278,752		1,541,910	5,278,752
Available-for-sale Securities, Gross Unrealized Gain					0
Available-for-sale Securities, Gross Unrealized Loss					211,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	4,616,000	4,168,000		4,616,000	4,168,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	602,000	176,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	83,000	35,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,134,000	1,111,000		1,134,000	$ 1,111,000
Marketable Securities, Realized Gain (Loss), Excluding Other than Temporary Impairments	0	$ 8,000	$ 8,410
Available-for-sale Securities, Noncurrent	$ 4,368,000			$ 4,368,000