Stockholders' Equity (Compliance with Regulatory Capital Requirements) (Details) $ in Thousands	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2018
Tier 1 leverage capital, Actual, Amount	$ 3,886,926	$ 3,584,474
Common equity tier 1 (to risk weighted assets), Actual, Amount	3,886,926	3,584,474
Tier 1 capital (to risk weighted assets), Actual, Amount	3,886,926	3,584,474
Total capital (to risk weighted assets), Actual, Amount	$ 4,378,748	$ 4,049,245
Tier 1 leverage capital, Actual, Ratio %	0.1129	0.101
Common equity tier 1 (to risk weighted assets), Actual, Ratio %	14.14%	12.33%
Tier 1 capital (to risk weighted assets), Actual, Ratio %	0.1414	0.1233
Total capital (to risk weighted assets), Actual, Ratio %	0.1593	0.1393
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount	$ 1,377,216	$ 1,419,209
Common equity tier 1 (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,237,066	1,308,034
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,649,421	1,744,046
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	$ 2,199,228	$ 2,325,394
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	$ 1,721,520	$ 1,774,011
Common equity tier 1 (to risk weighted assets), Required To Be Well Capitalized, Amount	1,786,873	1,889,383
Tier 1 capital (to risk weighted assets), Required To Be Well Capitalized, Amount	2,199,228	2,325,394
Total capital (to risk weighted assets), Required To Be Well Capitalized, Amount	$ 2,749,036	$ 2,906,743
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	$ 3,754,217	$ 3,493,531
Common equity tier 1 (to risk weighted assets), Actual, Amount	3,754,217	3,493,531
Tier 1 capital (to risk weighted assets), Actual, Amount	3,754,217	3,493,531
Total capital (to risk weighted assets), Actual, Amount	$ 4,073,539	$ 3,785,802
Tier 1 leverage capital, Actual, Ratio %	0.1091	0.0986
Common equity tier 1 (to risk weighted assets), Actual, Ratio %	13.67%	12.03%
Tier 1 capital (to risk weighted assets), Actual, Ratio %	0.1367	0.1203
Total capital (to risk weighted assets), Actual, Ratio %	0.1483	0.1304
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount	$ 1,376,113	$ 1,417,854
Common equity tier 1 (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,235,956	1,306,464
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,647,942	1,741,952
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	$ 2,197,256	$ 2,322,603
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	$ 1,720,142	$ 1,772,318
Common equity tier 1 (to risk weighted assets), Required To Be Well Capitalized, Amount	1,785,270	1,887,115
Tier 1 capital (to risk weighted assets), Required To Be Well Capitalized, Amount	2,197,256	2,322,603
Total capital (to risk weighted assets), Required To Be Well Capitalized, Amount	$ 2,746,570	$ 2,903,254
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