CAPITAL AND REGULATORY MATTERS (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
BXS_CommonEquityTierOneCapitalRequiredToBeWellCapitalizedToriskweightedassets (in Hundredths)	6.50%
Tier one core capital required for capital adequacy to risk-weighted assets (in hundredths)	4.00%	4.00%
Tier one total capital required for capital adequacy to risk-weighted assets (in hundredths)	8.00%	8.00%
Tier one leverage ratio required for capital adequacy to average assets (in hundredths)	4.00%	4.00%
Tier one risk based capital required to be well capitalized to risk-weighted assets (in hundredths)	8.00%	8.00%
Total capital required to be well capitalized to risk-weighted assets (in hundredths)	10.00%	10.00%
Tier one leverage capital required to be well capitalized to average assets (in hundredths)	5.00%	5.00%
Common Equity Tier 1 Capital (to risk-wieghted assets) [Abstract]
bxs_Common Equity Tier 1 Capital to Risk weighted assets (in hundredths)		12.07%
Bxs_Common Equity Tier 1 Capital		$ 1,402,041
Tier I capital (to risk-weighted assets) [Abstract]
Tier I capital	$ 1,425,239	$ 1,425,239	$ 1,351,807
Tier I capital to risk-weighted assets (in hundredths)	12.27%	12.27%	13.27%
Total capital (to risk-weighted assets) [Abstract]
Total capital	$ 1,552,280	$ 1,552,280	$ 1,479,791
Total capital to risk-weighted assets (in hundredths)	13.37%	13.37%	14.52%
Tier I leverage capital (to average assets) [Abstract]
Tier I leverage capital	$ 1,425,239	$ 1,425,239	$ 1,351,807
Tier I leverage capital to average assets (in hundredths)	10.61%	10.61%	10.55%
BancorpSouth Bank [Member]
Common Equity Tier 1 Capital (to risk-wieghted assets) [Abstract]
bxs_Common Equity Tier 1 Capital to Risk weighted assets (in hundredths)		11.80%
Bxs_Common Equity Tier 1 Capital		$ 1,369,419
Tier I capital (to risk-weighted assets) [Abstract]
Tier I capital	$ 1,369,419	$ 1,369,419	$ 1,298,449
Tier I capital to risk-weighted assets (in hundredths)	11.80%	11.80%	12.76%
Total capital (to risk-weighted assets) [Abstract]
Total capital	$ 1,496,460	$ 1,496,460	$ 1,426,433
Total capital to risk-weighted assets (in hundredths)	12.90%	12.90%	14.02%
Tier I leverage capital (to average assets) [Abstract]
Tier I leverage capital	$ 1,369,419	$ 1,369,419	$ 1,298,449
Tier I leverage capital to average assets (in hundredths)	10.23%	10.23%	10.17%