Note 4 - Derivatives and Hedging Activities (Details) - Changes in Fair Values of Derivative Financial Instruments - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount of income (loss) recognized in other comprehensive income, net of tax	$ (2,378,921)	$ 2,220,865	$ 4,476,014	$ 5,230,784	$ (158,056)	$ 9,706,798
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized loss at beginning of period, net of tax	(637,037,000,000)	(399,367,000,000)			(399,367,000,000)
Amount of income (loss) recognized in other comprehensive income, net of tax	53,165,000,000		(251,149,000,000)		(185,407,000,000)	(251,149,000,000)
Unrealized loss at end of period	(574,311,000,000)	$ (637,037,000,000)	$ (251,149,000,000)		(574,311,000,000)	$ (251,149,000,000)
Hedge Ineffectiveness [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCI to noninterest income related to hedge ineffectiveness	7,755,000,000				8,097,000,000
Amount reclassified from AOCI to interest expense related to caplet amortization	7,755,000,000				8,097,000,000
Caplet Amortization [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCI to noninterest income related to hedge ineffectiveness	1,806,000,000				2,366,000,000
Amount reclassified from AOCI to interest expense related to caplet amortization	$ 1,806,000,000				$ 2,366,000,000