Stockholders' Equity (Compliance with Regulatory Capital Requirements) (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2018
Tier 1 leverage capital, Actual, Amount	$ 3,279,419	$ 2,890,770
Common equity tier 1 (to risk weighted assets), Actual, Amount	3,279,419	2,890,770
Tier 1 capital (to risk weighted assets), Actual, Amount	3,279,419	2,890,770
Total capital (to risk weighted assets), Actual, Amount	$ 3,726,834	$ 3,345,387
Tier 1 leverage capital, Actual, Ratio %	0.0953	0.0825
Common equity tier 1 (to risk weighted assets), Actual, Ratio %	11.41%	11.09%
Tier 1 capital (to risk weighted assets), Actual, Ratio %	0.1141	0.1109
Total capital (to risk weighted assets), Actual, Ratio %	0.1297	0.1284
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount	$ 1,376,092	$ 1,402,223
Common equity tier 1 (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,293,035	1,172,563
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,724,046	1,563,417
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	$ 2,298,728	$ 2,084,557
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Ratio %	0.0400	0.0400	0.040
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 %	0.0600	0.0600	0.060
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	0.0800	0.0800	0.080
Tier 1 leverage capital, Required To Be Well Capitalized, Amount	$ 1,720,115	$ 1,752,779
Common equity tier 1 (to risk weighted assets), Required To Be Well Capitalized, Amount	1,867,717	1,693,702
Tier 1 capital (to risk weighted assets), Required To Be Well Capitalized, Amount	2,298,728	2,084,557
Total capital (to risk weighted assets), Required To Be Well Capitalized, Amount	$ 2,873,411	$ 2,605,696
Tier 1 leverage capital, Required To Be Well Capitalized, Ratio %	0.0500	0.0500	0.050
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 %	0.0800	0.0800	0.080
Total capital (to risk weighted assets), Required To Be Well Capitalized, Ratio %	0.1000	0.1000	0.100
Hancock Whitney Bank [Member]
Tier 1 leverage capital, Actual, Amount	$ 3,279,536	$ 2,926,874
Common equity tier 1 (to risk weighted assets), Actual, Amount	3,279,536	2,926,874
Tier 1 capital (to risk weighted assets), Actual, Amount	3,279,536	2,926,874
Total capital (to risk weighted assets), Actual, Amount	$ 3,554,451	$ 3,208,991
Tier 1 leverage capital, Actual, Ratio %	0.0954	0.0836
Common equity tier 1 (to risk weighted assets), Actual, Ratio %	11.43%	11.24%
Tier 1 capital (to risk weighted assets), Actual, Ratio %	0.1143	0.1124
Total capital (to risk weighted assets), Actual, Ratio %	0.1239	0.1233
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount	$ 1,374,761	$ 1,401,157
Common equity tier 1 (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,291,467	1,171,341
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,721,956	1,561,788
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	$ 2,295,942	$ 2,082,384
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Ratio %	0.0400	0.0400
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 %	0.0600	0.0600
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	0.0800	0.0800
Tier 1 leverage capital, Required To Be Well Capitalized, Amount	$ 1,718,451	$ 1,751,447
Common equity tier 1 (to risk weighted assets), Required To Be Well Capitalized, Amount	1,865,453	1,691,937
Tier 1 capital (to risk weighted assets), Required To Be Well Capitalized, Amount	2,295,942	2,082,384
Total capital (to risk weighted assets), Required To Be Well Capitalized, Amount	$ 2,869,927	$ 2,602,980
Tier 1 leverage capital, Required To Be Well Capitalized, Ratio %	0.0500	0.0500
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 %	0.0800	0.0800
Total capital (to risk weighted assets), Required To Be Well Capitalized, Ratio %	0.1000	0.1000