Note 2 - Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Callable Securities [Member] | US States and Political Subdivisions Debt Securities [Member]
Amortized Cost	$ 153,065,142
Fair Value	156,170,970
US States and Political Subdivisions Debt Securities [Member] | Callable Securities [Member]
Amortized Cost	13,844,290
Fair Value	14,296,378
US States and Political Subdivisions Debt Securities [Member]
	284,759,115	$ 254,641,285
US Government-sponsored Enterprises Debt Securities [Member] | Callable Securities [Member]
Amortized Cost	23,616,009
Fair Value	23,718,901
Residential Mortgage Backed Securities [Member]
Amortized Cost	114,990,076
Fair Value	116,765,510
Other Securities [Member]
	1,050,000	1,050,000
Amortized Cost	1,684,787
Fair Value	2,134,009
Callable Securities [Member]
	37,460,299
	38,015,279
Due in one year or less	4,972,563
Due in one year or less	4,993,619
Due after one year through five years	20,232,407
Due after one year through five years	20,415,409
Due after five years	255,140,562
Due after five years	260,400,087
	280,345,532
	285,809,115	$ 255,691,285
Due in one year or less	2,133,829
Due in one year or less	2,141,186
Due after one year through five years	54,381,038
Due after one year through five years	55,669,426
Due after five years	53,017,064
Due after five years	53,903,653
	109,531,931
	111,714,265
	226,206,794
	$ 230,613,784