CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY AND COMPREHENSIVE INCOME (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Statement of Stockholders' Equity [Abstract]
Dividends per common share	$ 0.42	$ 0.40	$ 0.32
Tax effect of unrealized gain (loss) on securities	$ 1,081,686	$ 311,158	$ 1,826
Tax effect of reclassification adjustment for gains included in income	$ 46,129		$ 66,624