Note 2 - Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2013

Fair Value Disclosures [Abstract]

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

	Quoted Prices in Active Markets for Identical Items (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
December 31, 2013
Assets
Money market	$	3,206,079	$	—	$	—	$	3,206,079
Total assets	$	3,206,079	$	—	$	—	$	3,206,079
Liabilities
Warrants to purchase common stock	$	—	$	819,930	$	—		819,930
Total liabilities	$	—	$	819,930	$	—		819,930
December 31, 2012
Assets
Money market	$	2,497,053	$	—	$	—	$	2,497,053
Total assets	$	2,497,053	$	—	$	—	$	2,497,053
Total liabilities	$	—	$	—	$	—		—

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

	Convertible Common Stock Warrant Liability
Balance as of December 31, 2012	$	—
Amounts acquired or issued		897,190
Changes in estimated fair value		(77,260	)
Balance as of December 31, 2013	$	819,930

Fair Value Measurements, Nonrecurring [Table Text Block]

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Expense for the Year Ended December 31, 2012
Assets:
Goodwill		—		—	$	70,646,036	$	2,288,776
Total	$	—	$	—	$	70,646,036	$	2,288,776