Non-performing Loans and Impaired Loans - Commercial Loans Individually Evaluated for Impairment by Class of Loan (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance total	$ 8,355	$ 3,433	$ 8,355	$ 3,433
Total ending loans balance	8,358	3,451	8,358	3,451
Allowance For Loan Loss Allocated	924		924
Average Balance in Impaired Loans total	9,228	3,923	9,311	2,642
Cash/Accrual Interest Income Recognized, Total	(17)	7	96	25
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	6,573	3,433	6,573	3,433
Recorded Investment With no recorded allowance	6,576	3,451	6,576	3,451
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0	0
Average Balance in Impaired Loans With no recorded allowance	7,437	3,923	7,509	2,642
Cash/Accrual Interest Income Recognized, With no recorded allowance	(25)	7	88	25
Unpaid Principal Balance With an allowance recorded	1,782		1,782
Recorded Investment With an allowance recorded	1,782		1,782
Allowance For Loan Loss Allocated	924		924
Average Balance in Impaired Loans With an allowance recorded	1,791		1,802
Cash/Accrual Interest Income Recognized, With an allowance recorded	8		8
Commercial [Member] \| Owner Occupied Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	4,496	923	4,496	923
Recorded Investment With no recorded allowance	4,490	934	4,490	934
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0	0
Average Balance in Impaired Loans With no recorded allowance	5,014	1,167	5,077	1,033
Cash/Accrual Interest Income Recognized, With no recorded allowance	(25)	4	71	4
Unpaid Principal Balance With an allowance recorded	845		845
Recorded Investment With an allowance recorded	845		845
Allowance For Loan Loss Allocated	145		145
Average Balance in Impaired Loans With an allowance recorded	852		874
Commercial [Member] \| Non Owner Occupied Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	841	701	841	701
Recorded Investment With no recorded allowance	857	701	857	701
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0	0
Average Balance in Impaired Loans With no recorded allowance	936	468	1,119	308
Cash/Accrual Interest Income Recognized, With no recorded allowance	(5)		5	2
Unpaid Principal Balance With an allowance recorded	187		187
Recorded Investment With an allowance recorded	187		187
Allowance For Loan Loss Allocated	30		30
Average Balance in Impaired Loans With an allowance recorded	189		178
Cash/Accrual Interest Income Recognized, With an allowance recorded	4		4
Commercial [Member] \| Residential Spec Homes [Member]
Financing Receivable, Impaired [Line Items]
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0	0
Commercial [Member] \| Development & Spec Land [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	71	102	71	102
Recorded Investment With no recorded allowance	69	102	69	102
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0	0
Average Balance in Impaired Loans With no recorded allowance	69	222	72	230
Commercial [Member] \| Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance With no recorded allowance	1,165	1,707	1,165	1,707
Recorded Investment With no recorded allowance	1,160	1,714	1,160	1,714
Allowance For Loan Loss Allocated With no recorded allowance	0	0	0	0
Average Balance in Impaired Loans With no recorded allowance	1,418	2,066	1,241	1,071
Cash/Accrual Interest Income Recognized, With no recorded allowance	5	$ 3	12	$ 19
Unpaid Principal Balance With an allowance recorded	750		750
Recorded Investment With an allowance recorded	750		750
Allowance For Loan Loss Allocated	749		749
Average Balance in Impaired Loans With an allowance recorded	750		750
Cash/Accrual Interest Income Recognized, With an allowance recorded	$ 4		$ 4

Impaired financing receivable interest income accrual method and cash basis method.

No definition available.

Name:	hbnc_ImpairedFinancingReceivableInterestIncomeAccrualMethodAndCashBasisMethod
Namespace Prefix:	hbnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Impaired Financing Receivable With No Related Allowance

+ References

No definition available.

+ Details

Name:	hbnc_ImpairedFinancingReceivableWithNoRelatedAllowance
Namespace Prefix:	hbnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Impaired financing receivable with no related allowance interest income accrual method and cash basis method.

+ References

No definition available.

+ Details

Name:	hbnc_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethodAndCashBasisMethod
Namespace Prefix:	hbnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Impaired financing receivable with related allowance interest income accrual method and cash basis method.

+ References

No definition available.

+ Details

Name:	hbnc_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethodAndCashBasisMethod
Namespace Prefix:	hbnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

+ Details

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

- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

+ Details

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

- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

+ Details

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

- Definition

Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

+ Details

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

- Definition

Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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

- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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

- Definition

Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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