Acquisitions (Details Textual) (USD $)	9 Months Ended	12 Months Ended				12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended					12 Months Ended
	Sep. 30, 2011	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009	Jun. 04, 2011	Dec. 31, 2011 Common Stock	Jun. 04, 2011 Common Stock	Dec. 31, 2011 Trade name [Member] years	Jun. 04, 2011 Trade name [Member]	Dec. 31, 2011 Trust [Member] years	Jun. 04, 2011 Trust preferred securities subject to mandatory redemption [Member]	Dec. 31, 2011 Credit card receivables [Member] years	Jun. 04, 2011 Credit card receivables [Member]	Dec. 31, 2011 Core deposit intangibles [Member] years	Dec. 31, 2011 Mississippi Gulf Coast [Member]	Dec. 31, 2011 Bogalusa La [Member]	Sep. 16, 2011 Whitney Bank Divested Branches [Member]	Dec. 18, 2009 As Recorded by Peoples First Community Bank [Member] employees	Dec. 31, 2011 Whitney [Member]	Dec. 31, 2011 Peoples First Community Bank [Member]
Acquisitions (Textual) [Abstract]
Shares in Hancock for each share of Whitney						0.418
Business acquisition, fair value of shares issued							$ 1,300,000,000
TARP stock redeemed					307,700,000
Business acquisition, total purchase price					1,600,000,000
Number of bank branches divested															7	1
Loans		11,191,901,000	4,968,149,000														47,000,000
Deposits		15,713,579,000	6,775,719,000														180,000,000
Fair value refinement period, maximum years		1
Business acquisition, purchase price allocation, total assets acquired		11,200,000,000																1,700,000,000		20,700,000
Business acquisition, purchase price allocation, loans and leases acquired		6,500,000,000
Business acquisition, purchase price allocation, investment securities acquired		2,600,000,000
Core deposit intangible					224,000,000
Business acquisition purchase price allocation deposits					9,200,000,000
Business acquisition, purchase price allocation, liabilities assumed					10,100,000,000
Goodwill from Whitney acquisition at acquisition date		513,917,000																	589,000,000
Business acquisition, purchase price allocation, core deposit intangibles amount					189,400,000				11,700,000		11,100,000		11,300,000
CDI intangible assets, amortization life, minimum (in years)														12
CDI intangible assets, amortization life, maximum (in years)														20
Amortization life, years										12		15
Average amortization life, years								2.5
Business acquisition, merger related charges		86,800,000
Business combination, net income of acquirer included in consolidated statements		232,500,000
Merger related charges, total		35,800,000																	86,800,000
Contingent liabilities payments to employees, fair value					58,000,000
Contractual contingency assumed liabilities for systems conversion and replacement initiative, fair value					14,000,000
Number of branch operated																		29
Number of Employees																		437
Percentage of loan losses covered under loss share agreement		80.00%
Amount of loan losses covered under loss share agreement		385,000,000
Percentage of losses covered under loss share agreement		95.00%
Term for loss sharing on residential real estate loans		10 years
Term for loss sharing on non-residential real estate loans		5 years
Estimated Receivable From FDIC		325,600,000
FDIC loss share receivable		212,885,000	329,136,000
Fair value of the acquired performing receivables					5,900,000,000
Gross contractual receivable					6,800,000,000
Bargain purchase gain on acquisition				33,623,000
Business acquisition purchase price allocation assets acquired pretax		33,600,000
Average estimated life of the core deposit base				10 years
Average approximate life of portfolio				7 months
Provision for credit losses	0
Acquisition related costs			$ 3,200,000	$ 3,700,000
Acquired liabilities expected to be paid		1 year