Note 13 - Fair Value Measurements - Measurements On Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($)	Sep. 30, 2017	Mar. 31, 2017
Impaired loans	$ 8,589,469	$ 5,371,689
Foreclosed real estate	483,204	503,094
Premises and equipment held for sale	547,884	547,884
Fair Value, Inputs, Level 1 [Member]
Impaired loans
Foreclosed real estate
Premises and equipment held for sale
Fair Value, Inputs, Level 2 [Member]
Impaired loans
Foreclosed real estate
Premises and equipment held for sale
Fair Value, Inputs, Level 3 [Member]
Impaired loans	8,589,469	5,371,689
Foreclosed real estate	483,204	503,094
Premises and equipment held for sale	$ 547,884	$ 547,884