Note 2 - Summary of Significant Accounting Policies (Details) - Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
Balance at January 1	$ 0	$ 1,465,019
Adjustment resulting from change in fair value (a) and extinguishment of warrants recognized in earnings	0	749,452	[1]
1,053,670 common shares issued in exchange of surrender of 1,053,670 warrants	0	(2,212,707)
Balance at June 30	$ 0	$ 1,764

[1] Adjustment resulting from change in fair value is the amount of total gains or losses for the period attributable to the change in unrealized gains or losses relating to liabilities held at the reporting date. The unrealized gain or loss is recorded in change in fair value of warrant liability in the accompanying consolidated statements of income.