XML 46 R35.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Basis of Presentation and Nature of Operations (Details) | 9 Months Ended
--- | ---
Sep. 30, 2017 bank
Organization, Consolidation and Presentation of Financial Statements [Abstract] |
Number of retail banking office locations, ACNB | 22
Number of retail banking office locations, NWSB | 7

X
- Definition Number of full-service retail bank offices acquired. + References No definition available. + Details
Name: | acnb_NumberofFullserviceBankOfficesAcquired
Namespace Prefix: | acnb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Full-service Bank Offices attributable to the Parent Company. + References No definition available. + Details
Name: | acnb_NumberofFullserviceBankOfficesParent
Namespace Prefix: | acnb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration