Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Statements Of Comprehensive Income [Abstract]
Net Income	$ 7,643,911	$ 8,260,032	$ 13,350,488	$ 13,626,055
Other Comprehensive Income:
Unrealized Holding Gains Arising During the Period	6,090,245	5,549,436	6,452,115	7,226,583
Reclassification Adjustment for Net Gains Realized in Income	(3,802,704)	(2,209,257)	(5,913,472)	(4,997,715)
TOTAL COMPREHENSIVE INCOME	9,931,452	11,600,211	13,889,131	15,854,923
Less: Preferred Dividend	2,151,758	1,019,805	4,303,516	2,039,610
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 7,779,694	$ 10,580,406	$ 9,585,615	$ 13,815,313