Other Real Estate and Covered Other Real Estate (Details) (USD $)	9 Months Ended												9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013 Construction, Land Development And Other Land Properties [Member]	Dec. 31, 2012 Construction, Land Development And Other Land Properties [Member]	Sep. 30, 2013 1 - 4 Family Residential Properties [Member]	Dec. 31, 2012 1 - 4 Family Residential Properties [Member]	Sep. 30, 2013 Nonfarm, Nonresidential Properties [Member]	Dec. 31, 2012 Nonfarm, Nonresidential Properties [Member]	Sep. 30, 2013 Other Real Estate Properties [Member]	Dec. 31, 2012 Other Real Estate Properties [Member]	Sep. 30, 2013 BancTrust Financial Group, Inc. [Member]	Sep. 30, 2012 Bay Bank and Trust Company [Member]
Other Real Estate and Covered Other Real Estate [Abstract]
Loss, net on the sale of other real estate included in ORE/Foreclosure expense	$ (110,000)		$ (175,000)
Business Acquisition [Line Items]
Other real estate acquired	40,100,000		2,600,000										40,100,000	2,600,000
Other real estate, excluding covered other real estate [Rollforward]
Balance at beginning of period	78,189,000		79,053,000		66,200,000	46,957,000	15,280,000	8,134,000	32,249,000	22,760,000	2,600,000	338,000
Additions	73,890,000	[1]	32,428,000	[1]
Disposals	(29,605,000)		(24,248,000)
Writedowns	(6,145,000)		(4,758,000)
Balance at end of period	116,329,000		82,475,000		66,200,000	46,957,000	15,280,000	8,134,000	32,249,000	22,760,000	2,600,000	338,000
Total other real estate, excluding covered other real estate	$ 116,329,000		$ 82,475,000		$ 66,200,000	$ 46,957,000	$ 15,280,000	$ 8,134,000	$ 32,249,000	$ 22,760,000	$ 2,600,000	$ 338,000

[1] Includes $40.1 million of other real estate acquired from BancTrust at September 30, 2013, and $2.6 million of other real estate acquired from Bay Bank at September 30, 2012.