Loans and Allowance for Loan Losses (Troubled Debt Restructurings Modified by Portfolio Class) (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2018 USD ($) contract	Sep. 30, 2017 USD ($) contract	Sep. 30, 2018 USD ($) contract	Sep. 30, 2017 USD ($) contract
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	26	20	50	73
Pre-Modification Outstanding Recorded Investment	$ 24,595,000	$ 43,118,000	$ 94,367,000	$ 147,452,000
Post-Modification Outstanding Recorded Investment	$ 24,595,000	$ 43,118,000	$ 94,367,000	$ 147,454,000
Total Commercial [Member] \| Commercial Real Estate - Income Producing [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract			1	5
Pre-Modification Outstanding Recorded Investment			$ 1,564,000	$ 5,684,000
Post-Modification Outstanding Recorded Investment			$ 1,564,000	$ 5,684,000
Residential Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	8	7	11	13
Pre-Modification Outstanding Recorded Investment	$ 930,000	$ 970,000	$ 1,048,000	$ 2,068,000
Post-Modification Outstanding Recorded Investment	$ 930,000	$ 970,000	$ 1,048,000	$ 2,068,000
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	6		7	1
Pre-Modification Outstanding Recorded Investment	$ 89,000		$ 311,000	$ 40,000
Post-Modification Outstanding Recorded Investment	$ 89,000		$ 311,000	$ 42,000
Total Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	12	13	31	54
Pre-Modification Outstanding Recorded Investment	$ 23,576,000	$ 42,148,000	$ 91,444,000	$ 139,660,000
Post-Modification Outstanding Recorded Investment	$ 23,576,000	$ 42,148,000	$ 91,444,000	$ 139,660,000
Total Commercial And Industrial [Member] \| Total Commercial [Member] \| Commercial Non-Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	11	13	29	50
Pre-Modification Outstanding Recorded Investment	$ 23,347,000	$ 42,148,000	$ 85,306,000	$ 135,926,000
Post-Modification Outstanding Recorded Investment	$ 23,347,000	$ 42,148,000	$ 85,306,000	$ 135,926,000
Total Commercial And Industrial [Member] \| Total Commercial [Member] \| Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| contract	1		2	4
Pre-Modification Outstanding Recorded Investment	$ 229,000		$ 6,138,000	$ 3,734,000
Post-Modification Outstanding Recorded Investment	$ 229,000		$ 6,138,000	$ 3,734,000

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=hwc_CommercialRealEstateIncomeProducingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_EquitySecuritiesByIndustryAxis=us-gaap_CommercialAndIndustrialSectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=hwc_CommercialNonRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=hwc_CommercialRealEstateOwnerOccupiedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: