Note 13 - Fair Value Measurements - Impaired Loans and Foreclosed Real Estate, Measurements On Nonrecurring Basis (Details) - USD ($)	Jun. 30, 2017	Mar. 31, 2017
Premises and equipment held for sale	$ 547,884	$ 547,884
Fair Value, Measurements, Nonrecurring [Member]
Impaired loans	5,406,786	5,371,689
Foreclosed real estate	520,399	503,094
Premises and equipment held for sale	547,884
Premises and equipment held for sale		547,884
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Impaired loans
Foreclosed real estate
Premises and equipment held for sale
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Impaired loans
Foreclosed real estate
Premises and equipment held for sale
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Impaired loans	5,406,786	5,371,689
Foreclosed real estate	520,399	503,094
Premises and equipment held for sale	$ 547,884
Premises and equipment held for sale		$ 547,884