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

12 Months Ended

Dec. 31, 2014

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities [Table Text Block]

	December 31, 2014				December 31, 2013
	Cost		Fair Value		Cost		Fair Value
Short-term investments
Certificate of deposit	$	5,000,000	$	4,996,568	$	3,840,000	$	3,835,083
Bonds- corporate issuances		19,189,438		19,176,838		33,360,576		33,321,298
Total short-term investments	$	24,189,438	$	24,173,406	$	37,200,576	$	37,156,381

	December 31, 2014				December 31, 2013
	Cost		Fair Value		Cost		Fair Value
Short-term investment maturities
Within 3 months	$	16,881,490	$	16,872,158	$	7,799,032	$	7,797,689
Between 3-12 months		7,307,948		7,301,248		29,401,544		29,358,692
Total	$	24,189,438	$	24,173,406	$	37,200,576	$	37,156,381

Investment Income [Table Text Block]

	2014			2013			2012
Interest and dividends accrued and paid	$	1,015,182		$	748,947		$	712,947
Accretion of investment premium		(913,261	)		(669,344	)		(652,960	)
Losses on investment maturity and sales, net		(24,727	)		(92,346	)		(7,580	)
	$	77,194		$	(12,744	)	$	52,322

Schedule of Unrealized Loss on Investments [Table Text Block]

	December 31, 2014					December 31, 2013
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	–		–			$	6,650,095	$	1,907
Short-term investments with unrealized losses		24,173,406		(16,032	)		30,506,286		(46,073	)
Total	$	24,173,406	$	(16,032	)	$	37,156,381	$	(44,166	)