Note 27: Condensed Parent Company Statements: Condensed Income Statement -- Great Southern Bancorp, Inc. (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gain on Redemption of Trust Preferred Securities	$ 0	$ 0	$ (1,115)
Interest Expense	27,905	22,119	15,997
Statements of Income | Parent Company
Income before income tax and equity in undistributed earnings of subsidiaries	11,171	11,034	26,561
Income Tax Credits and Adjustments	(1,709)	(241)	(91)
Income before equity in earnings of subsidiaries	12,880	11,275	26,652
Equity in undistributed earnings of subsidiaries	38,684	34,067	19,850
Net income parent company	51,564	45,342	46,502
Statements of Income | Parent Company | Income
Dividends from subsidiary bank	17,500	12,000	27,000
Other Interest and Dividend Income	48	0	5
Gain on Redemption of Trust Preferred Securities	0	2,735	1,416
Other income (loss)	0	2	(7)
Total income	17,548	14,737	28,414
Statements of Income | Parent Company | Expense
Operating Expenses	1,330	1,322	1,139
Interest Expense	5,047	2,381	714
Total expense	$ 6,377	$ 3,703	$ 1,853