Note 3 - Short-term Investments Available for Sale (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities [Table Text Block]

	December 31, 2015				December 31, 2014
	Cost		Fair Value		Cost		Fair Value
Short-term investments
Certificate of deposit	$	4,800,000	$	4,798,810	$	5,000,000	$	4,996,568
Bonds- corporate issuances		6,003,748		6,001,080		19,189,438		19,176,838
Total short-term investments	$	10,803,748	$	10,799,890	$	24,189,438	$	24,173,406

	December 31, 2015				December 31, 2014
	Cost		Fair Value		Cost		Fair Value
Short-term investment maturities
Within 3 months	$	10,803,748	$	10,799,890	$	16,881,490	$	16,872,158
Between 3-12 months		–		–		7,307,948		7,301,248
Total	$	10,803,748	$	10,799,890	$	24,189,438	$	24,173,406

Investment Income [Table Text Block]

	2015			2014			2013
Interest and dividends accrued and paid	$	186,322		$	1,015,182		$	748,947
Accretion of investment premium		(122,998	)		(913,261	)		(669,344	)
Losses on investment maturity and sales, net		264			(24,727	)		(92,346	)
	$	63,588		$	77,194		$	(12,744	)

Schedule of Unrealized Loss on Investments [Table Text Block]

	December 31, 2015					December 31, 2014
Description of Securities	Fair Value		Unrealized Holding Gains (Losses)			Fair Value		Unrealized Holding Gains (Losses)
Available for Sale (all unrealized holding gains and losses are less than 12 months at date of measurement)
Short-term investments with unrealized gains	$	240,024	$	24		$	–	$	–
Short-term investments with unrealized losses		10,559,866		(3,882	)		24,173,406		(16,032	)
Total	$	10,799,890	$	(3,858	)	$	24,173,406	$	(16,032	)