Document and Entity Information (USD $)	3 Months Ended
	Mar. 31, 2012	May 14, 2012	Mar. 31, 2011
Document and Entity Information
Entity Registrant Name	Southern Missouri Bancorp Inc
Document Type	10-Q
Document Period End Date	Mar. 31, 2012
Amendment Flag	false
Entity Central Index Key	0000916907
Current Fiscal Year End Date	--09-30
Entity Common Stock, Shares Outstanding		3,250,476
Entity Public Float			$ 26,500,000
Entity Filer Category	Smaller Reporting Company
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2