Note 2 - Investment Securities (Details) - Amortized Cost and Fair Value of Securities by Contractual Maturity (USD $)	Mar. 31, 2014	Dec. 31, 2013
Securities held to maturity:
Due in one year or less	$ 2,298,028
Due in one year or less	2,299,876
Due after one year through five years	10,898,311
Due after one year through five years	10,876,493
Due after one year through five years	148,432,813
Due after one year through five years	144,441,491
	161,629,152
	157,617,860	138,640,105
Securities available for sale:
Due in one year or less	5,399,927
Due in one year or less	5,412,462
Due after one year through five years	51,172,655
Due after one year through five years	50,810,680
Due after five years	341,825,057
Due after five years	329,190,483
	398,397,639
	385,413,625
Securities with no stated maturity date, amortized cost	559,120,092
Securities with no stated maturity date, fair value	545,477,537
Residential Mortgage Backed Securities [Member]
Securities available for sale:
Securities with no stated maturity date, amortized cost	159,343,903
Securities with no stated maturity date, fair value	158,119,401
Other Securities [Member]
Securities held to maturity:
	1,050,000	1,050,000
Securities available for sale:
Securities with no stated maturity date, amortized cost	1,378,550
Securities with no stated maturity date, fair value	1,944,511
US States and Political Subdivisions Debt Securities [Member]
Securities held to maturity:
	156,567,860	137,590,105
US States and Political Subdivisions Debt Securities [Member] | Callable Securities [Member]
Securities available for sale:
Securities with no stated maturity date, amortized cost	22,063,064
Securities with no stated maturity date, fair value	22,190,224
Securities held to maturity:
Municipal securities	107,791,951
Municipal securities	104,916,513
US Government-sponsored Enterprises Debt Securities [Member] | Callable Securities [Member]
Securities available for sale:
Securities with no stated maturity date, amortized cost	307,435,005
Securities with no stated maturity date, fair value	295,518,088
Callable Securities [Member]
Securities available for sale:
Securities with no stated maturity date, amortized cost	329,498,069
Securities with no stated maturity date, fair value	$ 317,708,312