REGULATORY MATTERS (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
REGULATORY MATTERS [Abstract]
Tier one core capital required for capital adequacy to risk-weighted assets (in hundredths)		4.00%
Tier one total capital required for capital adequacy to risk-weighted assets (in hundredths)		8.00%
Tier one leverage ratio required for capital adequacy to average assets (in hundredths)		4.00%
Tier one risk based capital required to be well capitalized to risk-weighted assets (in hundredths)		6.00%
Total capital required to be well capitalized to risk-weighted assets (in hundredths)		10.00%
Tier one leverage capital required to be well capitalized to average assets (in hundredths)		5.00%
Tier I capital (to risk-weighted assets) [Abstract]
Tier I capital	$ 1,129,746	$ 1,070,744
Tier I capital to risk-weighted assets (in hundredths)	11.77%	10.61%
Total capital (to risk-weighted assets) [Abstract]
Total capital	1,250,801	1,197,626
Total capital to risk-weighted assets (in hundredths)	13.03%	11.87%
Tier I leverage capital (to average assets) [Abstract]
Tier I leverage capital	1,129,746	1,070,744
Tier I leverage capital to average assets (in hundredths)	8.85%	8.07%
BancorpSouth Bank [Member]
Tier I capital (to risk-weighted assets) [Abstract]
Tier I capital	1,099,369	1,040,714
Tier I capital to risk-weighted assets (in hundredths)	11.46%	10.32%
Total capital (to risk-weighted assets) [Abstract]
Total capital	1,220,424	1,167,596
Total capital to risk-weighted assets (in hundredths)	12.73%	11.58%
Tier I leverage capital (to average assets) [Abstract]
Tier I leverage capital	$ 1,099,369	$ 1,040,714
Tier I leverage capital to average assets (in hundredths)	8.67%	7.87%

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The amount of total capital as defined in the regulations.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

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Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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