Document And Entity Information (USD $)	3 Months Ended
	Mar. 31, 2012	May 01, 2012	Sep. 30, 2011
Entity Registrant Name	BANCORPSOUTH INC
Entity Central Index Key	0000701853
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 979,000,000
Entity Common Stock, Shares Outstanding		94,436,177
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2012