Note 5 - Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2015

Notes Tables

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

			Fair Value Measurements at Reporting Date Using
	June 30, 2015		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash & cash equivalents:
Money market funds	$	60,814,116	$	-	$	60,814,116	$	-
Investments:
Corporate debt securities	$	3,013,150	$	-	$	3,013,150	$	-
Bank certificates of deposit		15,500,000		-		15,500,000		-
Total investments	$	18,513,150	$	-	$	18,513,150	$	-

			Fair Value Measurements at Reporting Date Using
	December 31, 2014		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash & cash equivalents:
Money market funds	$	69,551,754	$	-	$	69,551,754	$	-
Bank certificates of deposit		3,000,000		-		3,000,000		-
Total cash & cash equivalents	$	72,551,754	$	-	$	72,551,754	$	-
Investments:
Bank certificates of deposit	$	6,750,000	$	-	$	6,750,000	$	-