PENSION, OTHER POST RETIREMENT BENEFIT AND PROFIT SHARING PLANS, Information about Plan Assets (Details) (USD $)			12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Equity Securities [Member]	Dec. 31, 2011 Equity Securities [Member]	Dec. 31, 2012 Debt Securities [Member]	Dec. 31, 2011 Debt Securities [Member]	Dec. 31, 2012 Cash and Cash Equivalents [Member]	Dec. 31, 2011 Cash and Cash Equivalents [Member]	Dec. 31, 2012 Pension Benefits [Member]	Dec. 31, 2011 Pension Benefits [Member]	Dec. 31, 2010 Pension Benefits [Member]	Dec. 31, 2009 Pension Benefits [Member]	Dec. 31, 2012 Pension Benefits [Member] Dodge & Cox Fund [Member]	Dec. 31, 2012 Pension Benefits [Member] Fidelity Advisor New Insight [Member]	Dec. 31, 2012 Pension Benefits [Member] T. Rowe Price Equity Income Fund [Member]	Dec. 31, 2012 Pension Benefits [Member] Vanguard Total Bond Market Index Institutional Fund [Member]	Dec. 31, 2012 Pension Benefits [Member] Pioneer Multi Asset Ultrashort Inc. Fund [Member]	Dec. 31, 2012 Pension Benefits [Member] Fidelity Total Bond [Member]	Dec. 31, 2012 Pension Benefits [Member] Brokered Certificates of Deposit [Member]	Dec. 31, 2011 Pension Benefits [Member] Brokered Certificates of Deposit [Member]	Dec. 31, 2012 Pension Benefits [Member] Brokered Certificates of Deposit [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits [Member] Brokered Certificates of Deposit [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits [Member] Brokered Certificates of Deposit [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits [Member] Brokered Certificates of Deposit [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits [Member] Brokered Certificates of Deposit [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits [Member] Brokered Certificates of Deposit [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits [Member] U.S. Agency Debt Obligations [Member]	Dec. 31, 2011 Pension Benefits [Member] U.S. Agency Debt Obligations [Member]	Dec. 31, 2012 Pension Benefits [Member] U.S. Agency Debt Obligations [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits [Member] U.S. Agency Debt Obligations [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits [Member] U.S. Agency Debt Obligations [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits [Member] U.S. Agency Debt Obligations [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits [Member] U.S. Agency Debt Obligations [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits [Member] U.S. Agency Debt Obligations [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits [Member] Mutual Funds [Member]	Dec. 31, 2011 Pension Benefits [Member] Mutual Funds [Member]	Dec. 31, 2012 Pension Benefits [Member] Mutual Funds [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits [Member] Mutual Funds [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits [Member] Mutual Funds [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits [Member] Mutual Funds [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits [Member] Mutual Funds [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits [Member] Mutual Funds [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits [Member] Common stock of BancorpSouth, Inc. [Member]	Dec. 31, 2011 Pension Benefits [Member] Common stock of BancorpSouth, Inc. [Member]	Dec. 31, 2012 Pension Benefits [Member] Common stock of BancorpSouth, Inc. [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits [Member] Common stock of BancorpSouth, Inc. [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits [Member] Common stock of BancorpSouth, Inc. [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits [Member] Common stock of BancorpSouth, Inc. [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits [Member] Common stock of BancorpSouth, Inc. [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits [Member] Common stock of BancorpSouth, Inc. [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits [Member] Money Market Funds [Member]	Dec. 31, 2011 Pension Benefits [Member] Money Market Funds [Member]	Dec. 31, 2012 Pension Benefits [Member] Money Market Funds [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits [Member] Money Market Funds [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits [Member] Money Market Funds [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits [Member] Money Market Funds [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits [Member] Money Market Funds [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits [Member] Money Market Funds [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits [Member] Total Investments [Member]	Dec. 31, 2011 Pension Benefits [Member] Total Investments [Member]	Dec. 31, 2012 Pension Benefits [Member] Total Investments [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits [Member] Total Investments [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits [Member] Total Investments [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits [Member] Total Investments [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits [Member] Total Investments [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits [Member] Total Investments [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits [Member] Accrued Interest and Dividends [Member]	Dec. 31, 2011 Pension Benefits [Member] Accrued Interest and Dividends [Member]	Dec. 31, 2012 Pension Benefits [Member] Cash [Member]	Dec. 31, 2011 Pension Benefits [Member] Cash [Member]	Dec. 31, 2012 Basic Plan [Member] Common stock of BancorpSouth, Inc. [Member]	Dec. 31, 2011 Basic Plan [Member] Common stock of BancorpSouth, Inc. [Member]
Actual weighted-average asset allocation [Abstract]
Actual weighted average asset allocations	100.00%	100.00%	32.92%	36.87%	61.19%	58.16%	5.89%	4.97%																																																															0.58%	0.46%
Target asset allocations [Abstract]
Target Plan Asset Allocations 2013			33.00%		67.00%		0.00%
Expected future benefit payments:
2013	$ 10,560,000
2014	11,650,000
2015	13,238,000
2016	11,965,000
2017	12,285,000
2017-2022	66,277,000
Fair value of plan assets [Abstract]
Fair value of plan assets									203,704,000	195,004,000	197,536,000	180,217,000							3,784,000	4,965,000							49,886,000	70,757,000							138,904,000	112,995,000							1,196,000	907,000							9,356,000	4,701,000							203,214,000	194,325,000							490,000	679,000	88,000	0	1,200,000	907,000
Fair value of plan assets																			3,784,000	4,965,000	0	0	3,784,000	4,965,000	0	0	49,886,000	70,757,000	0	0	49,886,000	70,757,000	0	0	138,904,000	112,995,000	138,904,000	112,995,000	0	0	0	0	1,196,000	907,000	1,196,000	907,000	0	0	0	0	9,356,000	4,701,000	0	0	9,356,000	4,701,000	0	0	203,126,000	194,325,000	140,100,000	113,902,000	63,026,000	80,423,000	0	0
Threshold of plan asset value at which individual investments are disclosed (in hundredths)	5.00%
Fair value of investments that represent 5% or more of total plan asset value													$ 11,339,000	$ 11,947,000	$ 11,151,000	$ 18,501,000	$ 15,129,000	$ 17,120,000