Note 4 - Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2014

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Total Fair Value on the Balance Sheet		Quoted Prices In Active Markets For Identical Assets /Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Recurring items as of December 31, 2014
Short-term investments available for sale	$	24,173,406	$	24,173,406		─	─
Non-recurring items as of December 31, 2014
In-process research and development (Note 5)	$	25,801,728	─		─		$	25,801,728
Goodwill (Note 5)	$	1,976,101	─		─		$	1,976,101
Recurring items as of December 31, 2013
Short-term investments available for sale	$	37,156,381	$	37,156,381	─		─
Liabilities:
Recurring items as of December 31, 2014
Common stock warrant liability (Note 13)	$	275,008	─		─		$	275,008
Earn-out milestone liability (Note 12)	$	13,663,710	─		─		$	13,663,710
As of December 31, 2013
Common stock warrant liability (Note 13)	$	3,026	─		─		$	3,026