CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) (USD $)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balances at Dec. 31, 2011	$ 53,101	$ 45,582,861	$ 100,628,900	$ (18,894,044)	$ (1,441,378)	$ 125,929,440
Net income	0	0	8,892,418	0	0	8,892,418
Other comprehensive income	0	0	0	0	1,369,523	1,369,523
Restricted stock awards	0	61,062	0	0	0	61,062
Restricted stock units for directors' deferred compensation plan	0	65,151	0	0	0	65,151
Cash dividends declared	0	0	(3,429,775)	0	0	(3,429,775)
Distribution of shares of treasury stock for directors' compensation	0	(28,121)	0	261,069	0	232,948
Distribution of shares of treasury stock for employee compensation	0	(8,052)	0	88,052	0	80,000
Distribution of shares of treasury stock for deferred directors' compensation	0	(81,747)	0	82,588	0	841
Distribution of shares of treasury stock granted for employee restricted stock awards	0	(53,412)	0	53,412	0	0
Purchase of shares of treasury stock	0	0	0	(579,051)	0	(579,051)
Sale of treasury stock	0	101	0	257,449		257,550
Balances at Sep. 30, 2012	53,101	45,537,843	106,091,543	(18,730,525)	(71,855)	132,880,107
Balances at Dec. 31, 2012	53,101	45,357,073	107,078,182	(18,566,490)	(2,806,929)	131,114,937
Net income	0	0	7,245,545	0	0	7,245,545
Other comprehensive income	0	0	0	0	(469,769)	(469,769)
Restricted stock awards	0	106,326	0	0	0	106,326
Restricted stock units for directors' deferred compensation plan	0	74,180	0	0	0	74,180
Cash dividends declared	0	0	(3,583,627)	0	0	(3,583,627)
Distribution of shares of treasury stock for directors' compensation	0	13,896	0	203,050	0	216,946
Distribution of shares of treasury stock for employee compensation	0	7,278	0	104,876	0	112,154
Distribution of shares of treasury stock for deferred directors' compensation	0	(74,623)	0	85,577	0	10,954
Purchase of shares of treasury stock	0	0	0	(92,630)	0	(92,630)
Sale of treasury stock	0	10,518	0	60,362	0	70,880
Forfeit of restricted stock awards	0	60,685	0	(60,685)		0
Balances at Sep. 30, 2013	$ 53,101	$ 45,555,333	$ 110,740,100	$ (18,265,940)	$ (3,276,698)	$ 134,805,896