Note 4 - Loans and Allowance for Loan Losses - Troubled Debt Restructurings by Modification Type (Details)	3 Months Ended
	Sep. 30, 2017 USD ($)
Post-modification outstanding recorded balance	$ 119,459
Interest Rate [Member]
Post-modification outstanding recorded balance	0
Term [Member]
Post-modification outstanding recorded balance	119,459
Combination [Member]
Post-modification outstanding recorded balance	0
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Post-modification outstanding recorded balance	0
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member] | Interest Rate [Member]
Post-modification outstanding recorded balance	0
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member] | Term [Member]
Post-modification outstanding recorded balance	0
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member] | Combination [Member]
Post-modification outstanding recorded balance	0
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Post-modification outstanding recorded balance	0
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member] | Interest Rate [Member]
Post-modification outstanding recorded balance	0
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member] | Term [Member]
Post-modification outstanding recorded balance	0
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member] | Combination [Member]
Post-modification outstanding recorded balance	0
Real Estate, Construction [Member]
Post-modification outstanding recorded balance	0
Real Estate, Construction [Member] | Interest Rate [Member]
Post-modification outstanding recorded balance	0
Real Estate, Construction [Member] | Term [Member]
Post-modification outstanding recorded balance	0
Real Estate, Construction [Member] | Combination [Member]
Post-modification outstanding recorded balance	0
Commercial Real Estate Portfolio Segment [Member]
Post-modification outstanding recorded balance	0
Commercial Real Estate Portfolio Segment [Member] | Interest Rate [Member]
Post-modification outstanding recorded balance	0
Commercial Real Estate Portfolio Segment [Member] | Term [Member]
Post-modification outstanding recorded balance	0
Commercial Real Estate Portfolio Segment [Member] | Combination [Member]
Post-modification outstanding recorded balance	0
Commercial Portfolio Segment [Member]
Post-modification outstanding recorded balance	0
Commercial Portfolio Segment [Member] | Interest Rate [Member]
Post-modification outstanding recorded balance	0
Commercial Portfolio Segment [Member] | Term [Member]
Post-modification outstanding recorded balance	0
Commercial Portfolio Segment [Member] | Combination [Member]
Post-modification outstanding recorded balance	0
Consumer and Other Loans [Member]
Post-modification outstanding recorded balance	119,459
Consumer and Other Loans [Member] | Interest Rate [Member]
Post-modification outstanding recorded balance	0
Consumer and Other Loans [Member] | Term [Member]
Post-modification outstanding recorded balance	119,459
Consumer and Other Loans [Member] | Combination [Member]
Post-modification outstanding recorded balance	$ 0