JUNIOR SUBORDINATED DEBT SECURITIES (Details) (USD $) In Thousands, except Share data, unless otherwise specified			12 Months Ended		11 Months Ended	2 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2002 Junior Subordinated Debt Securities of BancorpSouth Capital Trust I [Member]	Dec. 31, 2004 Junior Subordinated Debt Securities of Business Holding Company Trust I [Member]	Dec. 01, 2005 Junior Subordinated Debt Securities of American State Capital Trust I [Member]	Mar. 01, 2007 Junior Subordinated Debt Securities of Signature Bancshares Preferred Trust I [Member]	Mar. 01, 2007 Junior Subordinated Debt Securities of City Bancorp Preferred Trust I [Member]
Subordinated Borrowing [Line Items]
Subordinated debt	$ 160,312	$ 160,312	$ 128,900	$ 6,200	$ 6,700	$ 8,200	$ 10,300
Interest rate (in hundredths)			8.15%
Number of shares of trust preferred securities issued (in shares)			5,000,000	6,000	6,500	8,000	10,000
Interest rate of trust preferred securities issued (in hundredths)			8.15%
Face value of the trust preferred securities (in dollars per share)			$ 25
Maturity date of debt			Jan. 28, 2032	Apr. 07, 2034	Apr. 07, 2034	Oct. 08, 2033	Mar. 15, 2035
Maturity date of trust preferred securities			Jan. 28, 2032	Apr. 07, 2034	Apr. 07, 2034	Oct. 08, 2033	Mar. 15, 2035
Interest rate terms of debt				(per annum rate of interest, reset quarterly, equal to the three month London Interbank Offered Rate “LIBOR” plus 2.80% from January 30, 2004 to April 7, 2009 and thereafter at LIBOR plus 2.85%	three month LIBOR plus 2.80%	three-month LIBOR plus 3.00%	three-month LIBOR plus 2.2%
Interest rate terms of trust preferred securities				pay a per annum rate of interest, reset quarterly, equal to the three month London Interbank Offered Rate 'LIBOR' plus 2.80% from January 30, 2004 to April 7, 2009 and thereafter at LIBOR plus 2.85%	three month LIBOR plus 2.80%	three-month LIBOR plus 3.00%	three-month LIBOR plus 2.2%