XML 62 R50.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Loans - Narrative (Details) $ in Thousands |  | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jul. 01, 2017 USD ($) | Sep. 30, 2018 USD ($) Contract | Dec. 31, 2017 USD ($) 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 | Contract |  | 1 | 1
Number of loans which has periodic late payments | Contract |  | 1 |
Consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process |  | $ 800 | $ 848
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 |
Entity Loan Modification Program |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Proceeds from paid off troubled debt restructured loans |  | $ 832 | 283
New Windsor |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Interest rate fair value discount | $ 731 |  |
Credit fair value discount | $ 4,501 |  |
Maximum | Commercial real estate |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Financing receivable term |  | 20 years |
Loan-to-value ratio (no greater than) |  | 80.00% |
Maximum | Residential mortgage |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Financing receivable term |  | 30 years |
Loan-to-value ratio (no greater than) |  | 80.00% |
Loan-to-value ratio that requires private mortgage insurance (in excess of) |  | 80.00% |
Maximum | Home equity lines of credit |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Financing receivable term |  | 20 years |
Loan-to-value ratio (no greater than) |  | 90.00% |
Nonaccrual |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Financing Receivable, Modifications, Recorded Investment |  | $ 2,500 | 3,400
Accrual |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Financing Receivable, Modifications, Recorded Investment |  | $ 3,900 | $ 4,000

X
- Definition Business Combination, Acquired Receivables, Credit Fair Value Adjustments + References No definition available. + Details
Name: | acnb_BusinessCombinationAcquiredReceivablesCreditFairValueAdjustments
Namespace Prefix: | acnb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Business Combination, Acquired Receivables, Interest Rate Fair Value Adjustments + References No definition available. + Details
Name: | acnb_BusinessCombinationAcquiredReceivablesInterestRateFairValueAdjustments
Namespace Prefix: | acnb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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, Loan to Value Ratio of Appraised Value of Property, Required to have Private Mortgage Insurance if in excess of this percentage. + References No definition available. + Details
Name: | acnb_FinancingReceivableLoantoValueRatioofAppraisedValueofPropertyRequiredtohavePrivateMortgageInsurance
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 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 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 The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL49126937-111524 + 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109223946&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_LoanRestructuringModificationNameAxis=us-gaap_EntityLoanModificationProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=acnb_NewWindsorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
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_FinancingReceivablePortfolioSegmentAxis=acnb_HomeEquityLinesOfCreditPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=acnb_NonaccrualMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=acnb_AccrualMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |