Note 14: Income Taxes: Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Details
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Tax Exempt Income, Percent	(1.60%)	(2.10%)	(2.40%)
Effective Income Tax Rate Reconciliation, Tax Credit, Percent	(6.10%)	(7.30%)	(8.10%)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	1.10%	1.10%	1.40%
Initial impact of enactment of 2017 Tax Act	(0.40%)	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent	(1.30%)	0.00%	(0.80%)
Effective Income Tax Rate Reconciliation	26.70%	26.70%	25.10%