Note 20 - Fair Values of Financial Instruments - Significant Unobservable Inputs (Details)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Impaired loans, fair value disclosure	$ 3,505,288	$ 3,643,608
Impaired loans, fair value disclosure	3,505,288	3,643,608
Commercial Real Estate Portfolio Segment [Member]
Impaired loans, fair value disclosure	2,718,731	2,993,923
Impaired loans, fair value disclosure	2,718,731	2,993,923
One-to-four Family Residential Real Estate Portfolio Segment [Member]
Impaired loans, fair value disclosure	786,557	649,685
Impaired loans, fair value disclosure	786,557	649,685
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired loans, fair value disclosure	3,505,288	3,643,608
Impaired loans, fair value disclosure	3,505,288	3,643,608
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Valuation, Market Approach [Member] | Commercial Real Estate Portfolio Segment [Member]
Impaired loans, fair value disclosure	2,718,731	2,993,923
Impaired loans, fair value disclosure	$ 2,718,731	$ 2,993,923
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Valuation, Market Approach [Member] | Commercial Real Estate Portfolio Segment [Member] | Minimum [Member] | Measurement Input, Discount Rate [Member]
Impaired loans, Unobservable input valuation	0.17	0.17
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Valuation, Market Approach [Member] | Commercial Real Estate Portfolio Segment [Member] | Maximum [Member] | Measurement Input, Discount Rate [Member]
Impaired loans, Unobservable input valuation	0.18	0.18
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Valuation, Market Approach [Member] | One-to-four Family Residential Real Estate Portfolio Segment [Member]
Impaired loans, fair value disclosure	$ 786,557	$ 649,685
Impaired loans, fair value disclosure	$ 786,557	$ 649,685
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Valuation, Market Approach [Member] | One-to-four Family Residential Real Estate Portfolio Segment [Member] | Minimum [Member] | Measurement Input, Discount Rate [Member]
Impaired loans, Unobservable input valuation	0.17	0.17
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Valuation, Market Approach [Member] | One-to-four Family Residential Real Estate Portfolio Segment [Member] | Maximum [Member] | Measurement Input, Discount Rate [Member]
Impaired loans, Unobservable input valuation	0.18	0.18
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Internal Estimate [member]
Derivative IRLCs, fair value disclosure		$ 380,866
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Internal Estimate [member] | Measurement Input, Pull-through Rate [Member]
Derivative IRLCs, Unobservable input valuation		0.77