Note 8 - Fair Values of Financial Instruments - Significant Unobservable Inputs (Details)	Jun. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Impaired loans, fair value disclosure	$ 3,590,539	$ 3,643,608
Commercial Real Estate Portfolio Segment [Member]
Impaired loans, fair value disclosure	2,982,136	2,993,923
One-to-four Family Residential Real Estate Portfolio Segment [Member]
Impaired loans, fair value disclosure	608,403	649,685
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Impaired loans, fair value disclosure	3,590,539	3,643,608
Derivative IRLC's, fair value disclosure		$ 380,866
Derivative IRLC's, Unobservable input valuation		77
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	$ 2,982,136	$ 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	$ 608,403	$ 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] | Valuation, Market Approach [Member] | Commercial Real Estate Portfolio Segment [Member]

Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Valuation, Market Approach [Member] | One-to-four Family Residential Real Estate Portfolio Segment [Member]