Basis of Presentation (Narrative) (Details) $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Loan minimum balance included in specific reserve analysis	$ 1

Minimum Loan Balance Included In Specific Reserve Analysis

No definition available.

Name:	hwc_MinimumLoanBalanceIncludedInSpecificReserveAnalysis
Namespace Prefix:	hwc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration