Note 6 - Fair Value of Measurements (Details) - Assets and Liabilities at Fair Value on a Recurring Basis (USD $)	Mar. 31, 2014	Dec. 31, 2013
Assets:
Short-term investments available for sale Bonds – corporate issuances	$ 47,255,487	$ 37,156,381
As of March 31, 2014
Common stock warrant liability		3,026
Fair Value, Inputs, Level 1 [Member]
Assets:
Short-term investments available for sale Bonds – corporate issuances	47,255,487	37,156,381
Fair Value, Inputs, Level 3 [Member]
As of March 31, 2014
Common stock warrant liability		$ 3,026