Loans and Allowance for Loan Losses (Allowance for Loan Losses by Portfolio Class) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance	$ 217,308	$ 229,418
Allowance for loan losses: Net provision for loan losses	36,116	58,968	$ 110,659
Allowance for loan losses: Ending balance	194,514	217,308	229,418
Allowance for loan losses: Individually evaluated for impairment	5,114	18,566
Allowance for loan losses: Amounts related to purchased credit impaired loans	10,734	14,107
Allowance for loan losses: Collectively evaluated for impairment	178,666	184,635
Loans: Individually evaluated for impairment	268,755	317,197
Loans: Purchased credit impaired loans	129,596	147,537
Loans: Collectively evaluated for impairment	19,628,060	18,539,429
Loans receivable	20,026,411	19,004,163
Total Commercial [Member] \| Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance	13,709	13,509
Allowance for loan losses: Ending balance	17,638	13,709	13,509
Allowance for loan losses: Individually evaluated for impairment	210	1,326
Allowance for loan losses: Amounts related to purchased credit impaired loans	43	41
Allowance for loan losses: Collectively evaluated for impairment	17,385	12,342
Loans: Individually evaluated for impairment	2,701	15,530
Loans: Purchased credit impaired loans	3,757	2,742
Loans: Collectively evaluated for impairment	2,335,321	2,366,327
Loans receivable	2,341,779	2,384,599
Total Commercial [Member] \| Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance	7,372	6,271
Allowance for loan losses: Ending balance	15,647	7,372	6,271
Allowance for loan losses: Individually evaluated for impairment	1	11
Allowance for loan losses: Amounts related to purchased credit impaired loans	83	172
Allowance for loan losses: Collectively evaluated for impairment	15,563	7,189
Loans: Individually evaluated for impairment	121	363
Loans: Purchased credit impaired loans	3,387	5,829
Loans: Collectively evaluated for impairment	1,544,827	1,367,229
Loans receivable	1,548,335	1,373,421
Residential Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance	24,844	25,361
Allowance for loan losses: Ending balance	23,782	24,844	25,361
Allowance for loan losses: Individually evaluated for impairment	444	189
Allowance for loan losses: Amounts related to purchased credit impaired loans	9,766	12,258
Allowance for loan losses: Collectively evaluated for impairment	13,572	12,397
Loans: Individually evaluated for impairment	3,876	10,640
Loans: Purchased credit impaired loans	105,430	119,553
Loans: Collectively evaluated for impairment	2,800,775	2,560,279
Loans receivable	2,910,081	2,690,472
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance	30,503	26,142
Allowance for loan losses: Ending balance	25,938	30,503	26,142
Allowance for loan losses: Individually evaluated for impairment	216	118
Allowance for loan losses: Amounts related to purchased credit impaired loans	388	646
Allowance for loan losses: Collectively evaluated for impairment	25,334	29,739
Loans: Individually evaluated for impairment	1,007	1,292
Loans: Purchased credit impaired loans	4,181	6,178
Loans: Collectively evaluated for impairment	2,142,679	2,107,825
Loans receivable	2,147,867	2,115,295
Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs	(74,622)	(87,261)
Allowance for loan losses: Recoveries	22,360	18,709
Allowance for loan losses: Net provision for loan losses	36,116	58,968
Allowance for loan losses: Other	(6,648)
Allowance for loan losses: Increase (decrease) in FDIC loss share receivable		(2,526)
Non-Purchased Credit Impaired Loans [Member] \| Total Commercial [Member] \| Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs	(1,633)	(259)
Allowance for loan losses: Recoveries	221	988
Allowance for loan losses: Net provision for loan losses	5,341	(529)
Non-Purchased Credit Impaired Loans [Member] \| Total Commercial [Member] \| Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs	(334)	(696)
Allowance for loan losses: Recoveries	96	1,603
Allowance for loan losses: Net provision for loan losses	8,513	194
Non-Purchased Credit Impaired Loans [Member] \| Residential Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs	(614)	(2,839)
Allowance for loan losses: Recoveries	2,179	1,064
Allowance for loan losses: Net provision for loan losses	(2,627)	3,602
Allowance for loan losses: Increase (decrease) in FDIC loss share receivable		(2,344)
Non-Purchased Credit Impaired Loans [Member] \| Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs	(23,913)	(31,430)
Allowance for loan losses: Recoveries	5,162	6,680
Allowance for loan losses: Net provision for loan losses	20,834	29,246
Allowance for loan losses: Other	(6,648)
Allowance for loan losses: Increase (decrease) in FDIC loss share receivable		(135)
Total Commercial And Industrial [Member] \| Total Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance	140,880	158,135
Allowance for loan losses: Ending balance	111,509	140,880	158,135
Allowance for loan losses: Individually evaluated for impairment	4,243	16,922
Allowance for loan losses: Amounts related to purchased credit impaired loans	454	990
Allowance for loan losses: Collectively evaluated for impairment	106,812	122,968
Loans: Individually evaluated for impairment	261,050	289,372
Loans: Purchased credit impaired loans	12,841	13,235
Loans: Collectively evaluated for impairment	10,804,458	10,137,769
Loans receivable	11,078,349	10,440,376
Total Commercial And Industrial [Member] \| Total Commercial [Member] \| Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance	127,918	147,052
Allowance for loan losses: Ending balance	97,752	127,918	147,052
Allowance for loan losses: Individually evaluated for impairment	3,636	16,129
Allowance for loan losses: Amounts related to purchased credit impaired loans	239	525
Allowance for loan losses: Collectively evaluated for impairment	93,877	111,264
Loans: Individually evaluated for impairment	239,384	267,881
Loans: Purchased credit impaired loans	6,629	5,941
Loans: Collectively evaluated for impairment	8,374,588	8,024,115
Loans receivable	8,620,601	8,297,937
Total Commercial And Industrial [Member] \| Total Commercial [Member] \| Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance	12,962	11,083
Allowance for loan losses: Ending balance	13,757	12,962	$ 11,083
Allowance for loan losses: Individually evaluated for impairment	607	793
Allowance for loan losses: Amounts related to purchased credit impaired loans	215	465
Allowance for loan losses: Collectively evaluated for impairment	12,935	11,704
Loans: Individually evaluated for impairment	21,666	21,491
Loans: Purchased credit impaired loans	6,212	7,294
Loans: Collectively evaluated for impairment	2,429,870	2,113,654
Loans receivable	2,457,748	2,142,439
Total Commercial And Industrial [Member] \| Non-Purchased Credit Impaired Loans [Member] \| Total Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs	(48,128)	(52,037)
Allowance for loan losses: Recoveries	14,702	8,374
Allowance for loan losses: Net provision for loan losses	4,055	26,455
Allowance for loan losses: Increase (decrease) in FDIC loss share receivable		(47)
Total Commercial And Industrial [Member] \| Non-Purchased Credit Impaired Loans [Member] \| Total Commercial [Member] \| Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs	(40,069)	(51,479)
Allowance for loan losses: Recoveries	14,385	7,526
Allowance for loan losses: Net provision for loan losses	(4,482)	24,866
Allowance for loan losses: Increase (decrease) in FDIC loss share receivable		(47)
Total Commercial And Industrial [Member] \| Non-Purchased Credit Impaired Loans [Member] \| Total Commercial [Member] \| Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs	(8,059)	(558)
Allowance for loan losses: Recoveries	317	848
Allowance for loan losses: Net provision for loan losses	$ 8,537	$ 1,589

Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

+ Details

Name:	us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAllowanceForLoanLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

+ Details

Name:	us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesCarryingAmountNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Change in carrying amount of the indemnification asset relating to loss sharing agreements with the Federal Deposit Insurance Corporation (FDIC). The change includes for example, but is not limited to, acquisitions, additional estimated losses, disposals, cash payments, accretion of discount and write-offs, net of recoveries.

+ References

No definition available.

+ Details

Name:	us-gaap_FDICIndemnificationAssetPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

+ References

+ Details

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

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

+ Details

Name:	us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

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

- Definition

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_ProvisionForLoanLeaseAndOtherLosses
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=hbhc_CommercialRealEstateIncomeProducingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
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_ReceivablesAcquiredWithDeterioratedCreditQualityAxis=hbhc_NonPurchasedCreditImpairedMember
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=hbhc_CommercialNonRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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