Note 26: Condensed Parent Company Statements: Condensed Cash Flow Statement -- Great Southern Bancorp, Inc. (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Prepaid expenses and other assets	$ (1,336)	$ 3,002	$ (5,227)
Net cash provided by operating activities	86,419	94,195	62,817
Net cash provided by investing activities	(295,149)	(381,323)	81,379
Net cash used in financing activities	226,143	247,617	(181,712)
Parent Company
Operating Activity Net Income Parent Company	73,612	67,109	51,564
Increase (Decrease) Equity in Undistributed Earnings of Subsidiaries	(47,695)	(38,748)	(38,684)
Compensation expense for stock option grants	922	737	564
Amortization of interest rate derivative	434	154	441
Gain (Loss) on Sale of Other Investments	23	0	0
Prepaid expenses and other assets	(3)	13	132
Accounts Payable and Other Accrued Liabilities	226	182	(115)
Income taxes parent	300	(278)	6
Net cash provided by operating activities	27,819	29,169	13,908
Investment/Return of principal - other investments	2	0	0
Net cash provided by investing activities	2	0	0
Payments for Repurchase of Warrants	(849)	(903)	0
Dividends, Paid-in-kind	(29,052)	(15,819)	(12,894)
Stock options excercised	4,158	2,224	3,247
Net cash used in financing activities	(25,743)	(14,498)	(9,647)
Cash, Period Increase (Decrease)	2,078	14,671	4,261
Cash beginning of period	56,648	41,977	37,716
Cash end of period	58,726	56,648	41,977
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	$ 5,424	$ 5,001	$ 5,059