Stockholders' Equity (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Total capital (to risk weighted assets)
Actual, Amount	$ 2,100,000
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	11.50%
Tier 1 capital (to risk weighted assets)
Actual, Ratio %	9.50%
Required for Minimum Capital Adequacy, Ratio %	7.00%
Hancock [Member]
Total capital (to risk weighted assets)
Actual, Amount	1,783,037	846,541
Actual, Ratio %	13.59%	16.60%
Required for Minimum Capital Adequacy, Amount	1,049,495	407,970
Required for Minimum Capital Adequacy, Ratio %	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	10.00%
Tier 1 capital (to risk weighted assets)
Actual, Amount	1,506,218	782,301
Actual, Ratio %	11.48%	15.34%
Required for Minimum Capital Adequacy, Amount	524,748	203,985
Required for Minimum Capital Adequacy, Ratio %	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	6.00%
Tier 1 leverage capital
Actual, Amount	1,506,218	782,301
Actual, Ratio %	8.17%	9.65%
Required for Minimum Capital Adequacy, Amount	553,318	243,160
Required for Minimum Capital Adequacy, Ratio %	3.00%	3.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	5.00%
Hancock Bank [Member]
Total capital (to risk weighted assets)
Actual, Amount	437,225	446,894
Actual, Ratio %	14.21%	16.46%
Required for Minimum Capital Adequacy, Amount	246,072	217,206
Required for Minimum Capital Adequacy, Ratio %	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	307,590	271,507
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	10.00%	10.00%
Tier 1 capital (to risk weighted assets)
Actual, Amount	397,900	412,632
Actual, Ratio %	12.94%	15.20%
Required for Minimum Capital Adequacy, Amount	123,036	108,603
Required for Minimum Capital Adequacy, Ratio %	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	184,554	162,904
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	6.00%	6.00%
Tier 1 leverage capital
Actual, Amount	397,900	412,632
Actual, Ratio %	8.15%	8.03%
Required for Minimum Capital Adequacy, Amount	146,408	154,198
Required for Minimum Capital Adequacy, Ratio %	3.00%	3.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	244,013	256,996
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	5.00%	5.00%
Whitney Bank [Member]
Total capital (to risk weighted assets)
Actual, Amount	1,277,591
Actual, Ratio %	12.76%
Required for Minimum Capital Adequacy, Amount	801,025
Required for Minimum Capital Adequacy, Ratio %	8.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	1,001,281
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	10.00%
Tier 1 capital (to risk weighted assets)
Actual, Amount	1,091,770
Actual, Ratio %	10.90%
Required for Minimum Capital Adequacy, Amount	400,512
Required for Minimum Capital Adequacy, Ratio %	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	600,769
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	6.00%
Tier 1 leverage capital
Actual, Amount	1,091,770
Actual, Ratio %	8.19%
Required for Minimum Capital Adequacy, Amount	399,725
Required for Minimum Capital Adequacy, Ratio %	3.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	666,208
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	5.00%
Hancock Bank of Louisiana [Member]
Total capital (to risk weighted assets)
Actual, Amount		344,447
Actual, Ratio %		15.72%
Required for Minimum Capital Adequacy, Amount		175,339
Required for Minimum Capital Adequacy, Ratio %		8.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		219,174
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		10.00%
Tier 1 capital (to risk weighted assets)
Actual, Amount		316,905
Actual, Ratio %		14.46%
Required for Minimum Capital Adequacy, Amount		87,670
Required for Minimum Capital Adequacy, Ratio %		4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		131,504
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		6.00%
Tier 1 leverage capital
Actual, Amount		316,905
Actual, Ratio %		11.33%
Required for Minimum Capital Adequacy, Amount		83,878
Required for Minimum Capital Adequacy, Ratio %		3.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		139,797
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		5.00%
Hancock Bank of Alabama [Member]
Total capital (to risk weighted assets)
Actual, Amount		33,543
Actual, Ratio %		17.39%
Required for Minimum Capital Adequacy, Amount		15,432
Required for Minimum Capital Adequacy, Ratio %		8.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		19,290
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		10.00%
Tier 1 capital (to risk weighted assets)
Actual, Amount		31,102
Actual, Ratio %		16.12%
Required for Minimum Capital Adequacy, Amount		7,716
Required for Minimum Capital Adequacy, Ratio %		4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		11,574
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		6.00%
Tier 1 leverage capital
Actual, Amount		31,102
Actual, Ratio %		16.38%
Required for Minimum Capital Adequacy, Amount		5,698
Required for Minimum Capital Adequacy, Ratio %		3.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		$ 9,496
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		5.00%