Document and Entity Information - $ / shares		3 Months Ended
Nov. 01, 2018	Sep. 30, 2018
Details
Registrant Name		GREAT SOUTHERN BANCORP, INC.
Registrant CIK		0000854560
SEC Form		10-Q
Period End date		Sep. 30, 2018
Fiscal Year End		--12-31
Trading Symbol		gsbc
Tax Identification Number (TIN)		431524856
Number of common stock shares outstanding	14,158,300
Filer Category		Accelerated Filer
Current with reporting		Yes
Small Business		false
Emerging Growth Company		false
Amendment Flag		false
Document Fiscal Year Focus		2018
Document Fiscal Period Focus		Q3
Entity Incorporation, State Country Name		Maryland
Entity Address, Address Line One		1451 E. Battlefield
Entity Address, City or Town		Springfield
Entity Address, State or Province		Missouri
Entity Address, Postal Zip Code		65804
City Area Code		417
Local Phone Number		887-4400
Entity Listing, Par Value Per Share	$ 0.01

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