Loan Restructuring Modification, Measurement Input

No definition available.

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Namespace Prefix:	acnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty.

+ References

Reference 1: 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

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

- Definition

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

+ References

+ Details

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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://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 2: 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 3: 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 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

Period of increase in weighted average maturity of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ 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

+ Details

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

- Details

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Balance Type:
Period Type:

- Details

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- Details

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- Details

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

- Details

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

- Details

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

LOANS AND ALLOWANCE FOR CREDIT LOSSES - Loan Modification (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	$ 0
Financial Asset, Not Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	4,041
Financial Asset, 30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	0
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	0
Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	0
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount		$ 549
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage		0.40%
Financing Receivable, Modified, Weighted Average Term Increase from Modification		4 years 11 months 12 days
Commercial and industrial \| Financial Asset, Not Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	1,748
Commercial and industrial \| Financial Asset, 30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	0
Commercial and industrial \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	0
Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	0
Commercial real estate \| Financial Asset, Not Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	2,293
Commercial real estate \| Financial Asset, 30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	0
Commercial real estate \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans modified	0
Combination Payment Deferral and Interest Only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	4,041
Combination Payment Deferral and Interest Only Payments \| Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 1,748
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	1.20%
Combination Payment Deferral and Interest Only Payments \| Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount	$ 2,293
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage	0.20%