Percentage of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables.

Name:	us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesPercent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-34

Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-33

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

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

- Definition

Amortized cost of financing receivable modified during period for debtor experiencing financial difficulty.

+ References

+ Details

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

- Definition

Percentage of decrease in weighted-average contractual interest rate of financing receivable modified for debtor experiencing financial difficulty.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ContractualInterestRateReductionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

Loans and Allowance for Credit Losses - Amortized Cost Basis of Loans Modified (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis	$ 4,299	$ 329	$ 8,004	$ 1,290
Agricultural
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest rate concession	2.00%
Agricultural \| Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis	$ 598	$ 0	$ 598	$ 0
% of Total Class of Financing Receivable	0.54%	0.00%	0.54%	0.00%
Agricultural \| Interest rate reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis			$ 1,718	$ 0
% of Total Class of Financing Receivable			1.56%	0.00%
Mortgage, farmland \| Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis	$ 3,077	$ 0
% of Total Class of Financing Receivable	1.12%	0.00%
Construction, 1 to 4 family residential \| Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis			$ 365	$ 150
% of Total Class of Financing Receivable			0.39%	0.17%
Mortgage, farmland \| Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis			$ 3,378	$ 0
% of Total Class of Financing Receivable			1.22%	0.00%
Mortgage, 1 to 4 family first liens \| Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis	$ 154	$ 177	$ 154	$ 177
% of Total Class of Financing Receivable	0.01%	0.01%	0.01%	0.01%
Mortgage, commercial \| Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis	$ 283	$ 0	$ 282	$ 0
% of Total Class of Financing Receivable	0.05%	0.00%	0.05%	0.00%
Construction, land development and commercial \| Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis			$ 0	$ 196
% of Total Class of Financing Receivable				0.07%
Commercial and financial \| Term extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Basis	$ 187	$ 152	$ 1,509	$ 767
% of Total Class of Financing Receivable	0.07%	0.05%	0.53%	0.25%