OTHER REAL ESTATE OWNED (Details) (USD $)	3 Months Ended			12 Months Ended
	Mar. 31, 2012		Mar. 31, 2011	Dec. 31, 2011
Activity in other real estate owned [Roll Forward]
Balance at beginning of year	$ 173,805,000		$ 133,412,000	$ 133,412,000
Additions to foreclosed properties
New foreclosed properties	10,766,000		21,464,000	125,234,000
Reductions in foreclosed properties
Sales	(11,771,000)		(13,528,000)	(64,488,000)
Writedowns	(4,992,000)		(4,936,000)	(20,353,000)
Balance at end of year	167,808,000		136,412,000	173,805,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	167,808,000		136,412,000	173,805,000
Foreclosed property expenses [Abstract]
Total foreclosed property expenses	8,409,000		7,082,000
Realized net losses on dispositions and holding losses on valuations of foreclosed properties	5,800,000		5,400,000
Alabama and Florida Panhandle [Member]
Reductions in foreclosed properties
Balance at end of year	26,339,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	26,339,000
Arkansas [Member]
Reductions in foreclosed properties
Balance at end of year	4,906,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	4,906,000	[1]
Mississippi [Member]
Reductions in foreclosed properties
Balance at end of year	36,046,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	36,046,000	[1]
Missouri [Member]
Reductions in foreclosed properties
Balance at end of year	4,502,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	4,502,000
Greater Memphis Area [Member]
Reductions in foreclosed properties
Balance at end of year	62,875,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	62,875,000
Tennessee [Member]
Reductions in foreclosed properties
Balance at end of year	25,657,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	25,657,000	[1]
Texas and Louisiana [Member]
Reductions in foreclosed properties
Balance at end of year	3,203,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	3,203,000
Other Geographical Areas [Member]
Reductions in foreclosed properties
Balance at end of year	4,280,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	4,280,000
Commercial and industrial segment [Member]
Reductions in foreclosed properties
Balance at end of year	1,260,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	1,260,000
Commercial and industrial segment [Member] | Alabama and Florida Panhandle [Member]
Reductions in foreclosed properties
Balance at end of year	423,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	423,000
Commercial and industrial segment [Member] | Arkansas [Member]
Reductions in foreclosed properties
Balance at end of year	16,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	16,000	[1]
Commercial and industrial segment [Member] | Mississippi [Member]
Reductions in foreclosed properties
Balance at end of year	0	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	0	[1]
Commercial and industrial segment [Member] | Missouri [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Commercial and industrial segment [Member] | Greater Memphis Area [Member]
Reductions in foreclosed properties
Balance at end of year	821,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	821,000
Commercial and industrial segment [Member] | Tennessee [Member]
Reductions in foreclosed properties
Balance at end of year	0	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	0	[1]
Commercial and industrial segment [Member] | Texas and Louisiana [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Commercial and industrial segment [Member] | Other Geographical Areas [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	18,814,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	18,814,000
Real estate segment [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	775,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	775,000
Real estate segment [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	5,167,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	5,167,000
Real estate segment [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	9,374,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	9,374,000
Real estate segment [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	113,515,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	113,515,000
Real estate segment [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	16,979,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	16,979,000
Real estate segment [Member] | Alabama and Florida Panhandle [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	3,505,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	3,505,000
Real estate segment [Member] | Alabama and Florida Panhandle [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Alabama and Florida Panhandle [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	902,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	902,000
Real estate segment [Member] | Alabama and Florida Panhandle [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	1,564,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	1,564,000
Real estate segment [Member] | Alabama and Florida Panhandle [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	16,179,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	16,179,000
Real estate segment [Member] | Alabama and Florida Panhandle [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	3,557,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	3,557,000
Real estate segment [Member] | Arkansas [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	615,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	615,000	[1]
Real estate segment [Member] | Arkansas [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	26,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	26,000	[1]
Real estate segment [Member] | Arkansas [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	0	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	0	[1]
Real estate segment [Member] | Arkansas [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	656,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	656,000	[1]
Real estate segment [Member] | Arkansas [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	1,766,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	1,766,000	[1]
Real estate segment [Member] | Arkansas [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	1,744,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	1,744,000	[1]
Real estate segment [Member] | Mississippi [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	2,970,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	2,970,000	[1]
Real estate segment [Member] | Mississippi [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	22,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	22,000	[1]
Real estate segment [Member] | Mississippi [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	730,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	730,000	[1]
Real estate segment [Member] | Mississippi [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	2,583,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	2,583,000	[1]
Real estate segment [Member] | Mississippi [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	25,510,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	25,510,000	[1]
Real estate segment [Member] | Mississippi [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	3,241,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	3,241,000	[1]
Real estate segment [Member] | Missouri [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Missouri [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Missouri [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Missouri [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	2,113,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	2,113,000
Real estate segment [Member] | Missouri [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	1,965,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	1,965,000
Real estate segment [Member] | Missouri [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	307,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	307,000
Real estate segment [Member] | Greater Memphis Area [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	4,713,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	4,713,000
Real estate segment [Member] | Greater Memphis Area [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	586,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	586,000
Real estate segment [Member] | Greater Memphis Area [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	1,164,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	1,164,000
Real estate segment [Member] | Greater Memphis Area [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	1,829,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	1,829,000
Real estate segment [Member] | Greater Memphis Area [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	46,007,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	46,007,000
Real estate segment [Member] | Greater Memphis Area [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	7,318,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	7,318,000
Real estate segment [Member] | Tennessee [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	3,523,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	3,523,000	[1]
Real estate segment [Member] | Tennessee [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	141,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	141,000	[1]
Real estate segment [Member] | Tennessee [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	2,371,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	2,371,000	[1]
Real estate segment [Member] | Tennessee [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	164,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	164,000	[1]
Real estate segment [Member] | Tennessee [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	19,458,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	19,458,000	[1]
Real estate segment [Member] | Tennessee [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	0	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	0	[1]
Real estate segment [Member] | Texas and Louisiana [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	111,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	111,000
Real estate segment [Member] | Texas and Louisiana [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Texas and Louisiana [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Texas and Louisiana [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	174,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	174,000
Real estate segment [Member] | Texas and Louisiana [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	2,630,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	2,630,000
Real estate segment [Member] | Texas and Louisiana [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	233,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	233,000
Real estate segment [Member] | Other Geographical Areas [Member] | Consumer mortgages [Member]
Reductions in foreclosed properties
Balance at end of year	3,377,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	3,377,000
Real estate segment [Member] | Other Geographical Areas [Member] | Home equity [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Other Geographical Areas [Member] | Agricultural [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Other Geographical Areas [Member] | Commercial and industrial-owner occupied [Member]
Reductions in foreclosed properties
Balance at end of year	291,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	291,000
Real estate segment [Member] | Other Geographical Areas [Member] | Construction, acquisition and development [Member]
Reductions in foreclosed properties
Balance at end of year	0
Other real estate owned by geographical location, segment and class [Abstract]
Total	0
Real estate segment [Member] | Other Geographical Areas [Member] | Commercial [Member]
Reductions in foreclosed properties
Balance at end of year	579,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	579,000
All other receivables [Member]
Reductions in foreclosed properties
Balance at end of year	1,924,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	1,924,000
All other receivables [Member] | Alabama and Florida Panhandle [Member]
Reductions in foreclosed properties
Balance at end of year	209,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	209,000
All other receivables [Member] | Arkansas [Member]
Reductions in foreclosed properties
Balance at end of year	83,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	83,000	[1]
All other receivables [Member] | Mississippi [Member]
Reductions in foreclosed properties
Balance at end of year	990,000	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	990,000	[1]
All other receivables [Member] | Missouri [Member]
Reductions in foreclosed properties
Balance at end of year	117,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	117,000
All other receivables [Member] | Greater Memphis Area [Member]
Reductions in foreclosed properties
Balance at end of year	437,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	437,000
All other receivables [Member] | Tennessee [Member]
Reductions in foreclosed properties
Balance at end of year	0	[1]
Other real estate owned by geographical location, segment and class [Abstract]
Total	0	[1]
All other receivables [Member] | Texas and Louisiana [Member]
Reductions in foreclosed properties
Balance at end of year	55,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	55,000
All other receivables [Member] | Other Geographical Areas [Member]
Reductions in foreclosed properties
Balance at end of year	33,000
Other real estate owned by geographical location, segment and class [Abstract]
Total	$ 33,000

[1] Excludes the Greater Memphis Area.