Note 4: Loans and Allowance for Loan Losses: Performing Loans Classified as Troubled Debt Restructuring Loans (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)
Residential Mortgage
Troubled Debt Restructuring Performing Loans, Number	10	10
Construction Real Estate
Troubled Debt Restructuring Performing Loans, Number	0	0
Commercial Real Estate
Troubled Debt Restructuring Performing Loans, Number	13	13
Consumer Loan
Troubled Debt Restructuring Performing Loans, Number	0	0
Commercial Loan
Troubled Debt Restructuring Performing Loans, Number	6	6
Total loans
Troubled Debt Restructuring Performing Loans, Number	29	29
Performing Financial Instruments | Residential Mortgage
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 1,746	$ 1,756
Performing Financial Instruments | Construction Real Estate
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	0
Performing Financial Instruments | Commercial Real Estate
Financing Receivable, Modifications, Post-Modification Recorded Investment	8,063	5,206
Performing Financial Instruments | Consumer Loan
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	0
Performing Financial Instruments | Commercial Loan
Financing Receivable, Modifications, Post-Modification Recorded Investment	3,554	3,946
Performing Financial Instruments | Total loans
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 13,363	$ 10,908