Condensed Parent Company Information (Condensed Statements of Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income tax benefit	$ 58,346	$ 92,802	$ 37,627
Net income	323,770	215,632	149,296
Other comprehensive income (loss) net of income taxes	(46,307)	11,460	(39,937)
Comprehensive income	277,463	227,092	109,359
Hancock Whitney Corporation [Member]
Cash dividends received from bank subsidiaries	200,000	90,000	120,000
Noncash dividend from bank subsidiaries		11,708
Equity in earnings of subsidiaries greater than dividends received	137,914	124,531	39,293
Total operating income	337,914	226,239	159,293
Other expense, net	(18,728)	(16,931)	(16,614)
Income tax benefit	(4,584)	(6,324)	(6,617)
Net income	323,770	215,632	149,296
Other comprehensive income (loss) net of income taxes	(46,307)	11,460	(39,937)
Comprehensive income	$ 277,463	$ 227,092	$ 109,359