XML 50 R39.htm IDEA: XBRL DOCUMENT v3.7.0.1

Loans - Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017 USD ($) Contract	Dec. 31, 2016 USD ($) Contract	Dec. 31, 2013 Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Period for order of valuations (at least)	18 months
Number of troubled debt restructured loan paid off		1
Number of loans which has periodic late payments	1
Number of loans classified as troubled debt restructured loans with active forbearance agreements	2
Number of forbearance agreements negotiated			1
Consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process | $	$ 427	$ 471
Residential mortgage and commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold period past due to discontinue accrual interest on financing receivable	90 days
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold period past due for write-off of financing receivable (no later than)	120 days
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Period of financing receivable, updated valuation on real estate secured loans, 90 days past due	90 days
Number of Previous Months with No Updated Valuation Completed for Corporation to Update Valuation	12 months
Impaired financing receivable, valuation on real estate collateralized loans	30 days
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, loan to value ratio of appraised value of property	80.00%
Entity Loan Modification Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from paid off troubled debt restructured loans | $		$ 74
Maximum | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, term	20 years
Financing receivable, loan to value ratio of appraised value of property	80.00%
Maximum | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, term	30 years
Maximum | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, term	20 years
Financing receivable, loan to value ratio of appraised value of property	90.00%

X

- Definition

Financing Receivable, Loan to Value Ratio of Appraised Value of Property

+ References

No definition available.

+ Details

Name:	acnb_FinancingReceivableLoantoValueRatioofAppraisedValueofProperty
Namespace Prefix:	acnb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Financing Receivable, Modifications, Number of Contracts Paid Off

+ References

No definition available.

+ Details

Name:	acnb_FinancingReceivableModificationsNumberofContractsPaidOff
Namespace Prefix:	acnb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Financing Receivable, Modifications, Subsequent Default, Number of Contracts with Active Forbearance Agreements

+ References

No definition available.

+ Details

Name:	acnb_FinancingReceivableModificationsSubsequentDefaultNumberofContractswithActiveForbearanceAgreements
Namespace Prefix:	acnb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Financing Receivable Modifications Subsequent Default Periodic Late Payments

+ References

No definition available.

+ Details

Name:	acnb_FinancingReceivableModificationsSubsequentDefaultPeriodicLatePayments
Namespace Prefix:	acnb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Financing Receivable, Term

+ References

No definition available.

+ Details

Name:	acnb_FinancingReceivableTerm
Namespace Prefix:	acnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Forbearance Agreement, Number Of Negotiations

+ References

No definition available.

+ Details

Name:	acnb_ForbearanceAgreementNumberOfNegotiations
Namespace Prefix:	acnb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of Maximum Days of Loan Being Classified as Impaired for Corporation to Order Third Party Valuation

+ References

No definition available.

+ Details

Name:	acnb_NumberofMaximumDaysofLoanBeingClassifiedasImpairedforCorporationtoOrderThirdPartyValuation
Namespace Prefix:	acnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of Minimum Months for Corporation to Order Updated Valuation

+ References

No definition available.

+ Details

Name:	acnb_NumberofMinimumMonthsforCorporationtoOrderUpdatedValuation
Namespace Prefix:	acnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of Previous Months with No Updated Valuation Completed for Corporation to Update Valuation

+ References

No definition available.

+ Details

Name:	acnb_NumberofPreviousMonthswithNoUpdatedValuationCompletedforCorporationtoUpdateValuation
Namespace Prefix:	acnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Threshold Period Past Due for Corporation to Order Updated Valuation on Financing Receivable

+ References

No definition available.

+ Details

Name:	acnb_ThresholdPeriodPastDueforCorporationtoOrderUpdatedValuationonFinancingReceivable
Namespace Prefix:	acnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Threshold Period Past Due to Discontinue Accrual Interest on Financing Receivable

+ References

No definition available.

+ Details

Name:	acnb_ThresholdPeriodPastDuetoDiscontinueAccrualInterestonFinancingReceivable
Namespace Prefix:	acnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

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

X

- Definition

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL49126937-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

+ Details

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

X

- Definition

Cash received from principal payments made on loans related to operating activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3536-108585

+ Details

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

X

- Definition

Threshold period past due for financing receivable to write off as uncollectible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

Name:	us-gaap_LoanRestructuringModificationNameAxis=us-gaap_EntityLoanModificationProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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