Stockholders' Equity (Compliance with Regulatory Capital Requirements) (Details) $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2018
Tier 1 leverage capital, Actual, Amount	$ 3,584,474	$ 3,279,419
Common equity tier 1 (to risk weighted assets), Actual, Amount	3,584,474	3,279,419
Tier 1 capital (to risk weighted assets), Actual, Amount	3,584,474	3,279,419
Total capital (to risk weighted assets), Actual, Amount	$ 4,049,245	$ 3,726,834
Tier 1 leverage capital, Actual, Ratio %	0.101	0.0953
Common equity tier 1 (to risk weighted assets), Actual, Ratio %	12.33%	11.41%
Tier 1 capital (to risk weighted assets), Actual, Ratio %	0.1233	0.1141
Total capital (to risk weighted assets), Actual, Ratio %	0.1393	0.1297
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount	$ 1,419,209	$ 1,376,092
Common equity tier 1 (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,308,034	1,293,035
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,744,046	1,724,046
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	$ 2,325,394	$ 2,298,728
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Ratio %	0.04	0.04	0.04
Common equity tier 1 (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	4.50%	4.50%	4.50%
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	0.06	0.06	0.06
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	0.08	0.08	0.08
Tier 1 leverage capital, Required To Be Well Capitalized, Amount	$ 1,774,011	$ 1,720,115
Common equity tier 1 (to risk weighted assets), Required To Be Well Capitalized, Amount	1,889,383	1,867,717
Tier 1 capital (to risk weighted assets), Required To Be Well Capitalized, Amount	2,325,394	2,298,728
Total capital (to risk weighted assets), Required To Be Well Capitalized, Amount	$ 2,906,743	$ 2,873,411
Tier 1 leverage capital, Required To Be Well Capitalized, Ratio %	0.05	0.05	0.05
Common equity tier 1 (to risk weighted assets), Required To Be Well Capitalized, Ratio %	6.50%	6.50%	6.50%
Tier 1 capital (to risk weighted assets), Required To Be Well Capitalized, Ratio %	0.08	0.08	0.08
Total capital (to risk weighted assets), Required To Be Well Capitalized, Ratio %	0.10	0.10	0.10
Hancock Whitney Bank [Member]
Tier 1 leverage capital, Actual, Amount	$ 3,493,531	$ 3,279,536
Common equity tier 1 (to risk weighted assets), Actual, Amount	3,493,531	3,279,536
Tier 1 capital (to risk weighted assets), Actual, Amount	3,493,531	3,279,536
Total capital (to risk weighted assets), Actual, Amount	$ 3,785,802	$ 3,554,451
Tier 1 leverage capital, Actual, Ratio %	0.0986	0.0954
Common equity tier 1 (to risk weighted assets), Actual, Ratio %	12.03%	11.43%
Tier 1 capital (to risk weighted assets), Actual, Ratio %	0.1203	0.1143
Total capital (to risk weighted assets), Actual, Ratio %	0.1304	0.1239
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount	$ 1,417,854	$ 1,374,761
Common equity tier 1 (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,306,464	1,291,467
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,741,952	1,721,956
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	$ 2,322,603	$ 2,295,942
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Ratio %	0.04	0.04
Common equity tier 1 (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	4.50%	4.50%
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	0.06	0.06
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	0.08	0.08
Tier 1 leverage capital, Required To Be Well Capitalized, Amount	$ 1,772,318	$ 1,718,451
Common equity tier 1 (to risk weighted assets), Required To Be Well Capitalized, Amount	1,887,115	1,865,453
Tier 1 capital (to risk weighted assets), Required To Be Well Capitalized, Amount	2,322,603	2,295,942
Total capital (to risk weighted assets), Required To Be Well Capitalized, Amount	$ 2,903,254	$ 2,869,927
Tier 1 leverage capital, Required To Be Well Capitalized, Ratio %	0.05	0.05
Common equity tier 1 (to risk weighted assets), Required To Be Well Capitalized, Ratio %	6.50%	6.50%
Tier 1 capital (to risk weighted assets), Required To Be Well Capitalized, Ratio %	0.08	0.08
Total capital (to risk weighted assets), Required To Be Well Capitalized, Ratio %	0.10	0.10