Note 6 - Fair Value (Details) - Assets Measured at Fair Value on a Recurring Basis - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Securities available for sale:
U.S. govt. sponsored agency securities	$ 276,187,867	$ 323,434,982
Derivative instruments	450,651	856,024
	276,638,518	324,291,006
Impaired loans/leases	12,183,927	12,268,677
Impaired Loans/Leases [Member]
Securities available for sale:
Impaired loans/leases	4,969,221	4,545,966
Other Real Estate Owned [Member]
Securities available for sale:
Impaired loans/leases	7,214,706	7,722,711
US Government Agencies Debt Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	132,741,822	213,537,379
Residential Mortgage Backed Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	116,452,374	80,670,135
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	24,929,655	27,578,588
Other Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	2,064,016	1,648,880
Fair Value, Inputs, Level 1 [Member]
Securities available for sale:
	779	411
Fair Value, Inputs, Level 1 [Member] | Other Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	779	411
Fair Value, Inputs, Level 2 [Member]
Securities available for sale:
Derivative instruments	450,651	856,024
	276,637,739	324,290,595
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	132,741,822	213,537,379
Fair Value, Inputs, Level 2 [Member] | Residential Mortgage Backed Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	116,452,374	80,670,135
Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	24,929,655	27,578,588
Fair Value, Inputs, Level 2 [Member] | Other Securities [Member]
Securities available for sale:
U.S. govt. sponsored agency securities	2,063,237	1,648,469
Fair Value, Inputs, Level 3 [Member]
Securities available for sale:
Impaired loans/leases	12,183,927	12,268,677
Fair Value, Inputs, Level 3 [Member] | Impaired Loans/Leases [Member]
Securities available for sale:
Impaired loans/leases	4,969,221	4,545,966
Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member]
Securities available for sale:
Impaired loans/leases	$ 7,214,706	$ 7,722,711