Business Combinations (Details) (USD $)	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Trustmark National Bank [Member] Heritage Banking Group Business Acquisition [Member]	Apr. 15, 2011 Trustmark National Bank [Member] Heritage Banking Group Business Acquisition [Member]
Business Acquisition [Line Items]
Age of acquired entity (in years)			90 Y
FDIC loss-share transaction asset coverage agreement			$ 151,900,000
FDIC loss-share agreement covered loan and other real estate losses (in hundredths)			80.00%
FDIC loss-share agreement term for single family residential mortgage loans and foreclosed real estate (in years)			10 Y
FDIC loss-share agreement term for commercial loans and related foreclosures (in years)			5 Y
FDIC loss-share agreement reimbursement term for recoveries of covered losses (in years)			3 Y
Assets [Abstract]
Cash and due from banks				50,447,000
Federal funds sold				1,000,000
Securities available for sale				6,389,000
LHFI, excluding covered loans				9,644,000
Covered loans				97,770,000
Premises and equipment, net				55,000
Identifiable intangible assets				902,000
Covered other real estate				7,485,000
FDIC indemnification asset				33,333,000
Other assets				218,000
Total Assets	207,243,000	0		207,243,000
Liabilities [Abstract]
Deposits				204,349,000
Short-term borrowings				23,157,000
Other liabilities				730,000
Total Liabilities				228,236,000
Net assets acquired at fair value				(20,993,000)
Cash received on acquisition	78,896,000	0	28,449,000
Bargain purchase gain	7,456,000	0	7,456,000
Income taxes			2,852,000
Bargain purchase gain, net of taxes			4,604,000
Added revenue in period from acquisition			11,100,000
Added net income available to common shareholders in the period from acquisition			$ 5,900,000