Note 27: Condensed Parent Company Statements: Condensed Statement of Comprehensive Income -- Great Southern Bancorp, Inc. (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unrealized Appreciation (Depreciation) on Available for Sale Securities, Net	$ (1,229)	$ (478)	$ (2,363)
Parent Company
Net Comprehensive Income Parent Company	67,109	51,564	45,342
Unrealized Appreciation (Depreciation) on Available for Sale Securities, Net	0	0	(158)
Reclassification adjustment for gains included in net income	0	0	(1,742)
Change in Fair Value of Cash Flow Hedge, Net	0	161	87
Comprehensive Income of subsidiaries	8,114	(478)	(2,293)
Comprehensive Income parent	$ 75,223	$ 51,247	$ 41,236