Other Real Estate, excluding Covered Real Estate (Details) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Construction, land development and other land loans [Member]	Dec. 31, 2010 Construction, land development and other land loans [Member]	Sep. 30, 2011 1 - 4 Family residential properties [Member]	Dec. 31, 2010 1 - 4 Family residential properties [Member]	Sep. 30, 2011 Nonfarm, nonresidential properties [Member]	Dec. 31, 2010 Nonfarm, nonresidential properties [Member]	Sep. 30, 2011 Other real estate properties [Member]	Dec. 31, 2010 Other real estate properties [Member]	Sep. 30, 2011 Florida [Member]	Dec. 31, 2010 Florida [Member]	Sep. 30, 2011 Mississippi [Member]		Dec. 31, 2010 Mississippi [Member]		Sep. 30, 2011 Tennessee [Member]		Dec. 31, 2010 Tennessee [Member]		Sep. 30, 2011 Texas [Member]	Dec. 31, 2010 Texas [Member]
Non-covered other real estate [Rollforward]
Balance at beginning of period	$ 86,704	$ 90,095	$ 63,756	$ 61,963	$ 12,716	$ 13,509	$ 12,123	$ 9,820	$ 1,002	$ 1,412	$ 29,949	$ 32,370	$ 21,027	[1]	$ 24,181	[1]	$ 17,940	[2]	$ 16,407	[2]	$ 20,681	$ 13,746
Additions	48,975	51,213
Disposals	(35,234)	(41,322)
Writedowns	(10,848)	(15,264)
Balance at end of period	89,597	84,722	63,756	61,963	12,716	13,509	12,123	9,820	1,002	1,412	29,949	32,370	21,027	[1]	24,181	[1]	17,940	[2]	16,407	[2]	20,681	13,746
Gain (Loss), net on the sale of noncovered other real estate included in other expenses	474	(401)
Other non-covered real estate [Line Items]
Total other real estate, excluding covered other real estate	89,597	84,722	63,756	61,963	12,716	13,509	12,123	9,820	1,002	1,412	29,949	32,370	21,027	[1]	24,181	[1]	17,940	[2]	16,407	[2]	20,681	13,746
Other non-covered real estate by geographic location [Line Items]
Total other real estate, excluding covered other real estate	$ 89,597	$ 84,722	$ 63,756	$ 61,963	$ 12,716	$ 13,509	$ 12,123	$ 9,820	$ 1,002	$ 1,412	$ 29,949	$ 32,370	$ 21,027	[1]	$ 24,181	[1]	$ 17,940	[2]	$ 16,407	[2]	$ 20,681	$ 13,746

[1] (1) - Mississippi includes Central and Southern Mississippi Region

[2] 2) - Tennessee includes Memphis, Tennessee and Northern Mississippi Region