Short-term Borrowings And Long-Term Debt (Narrative) (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Jun. 28, 2006
Nov. 23, 2004
Debt Instrument [Line Items]        
Line-of credit (Open Repo Plus) with the FHLBP, Maximum days 364 days      
Federal fund lines $ 8,000,000      
Collateralized borrowing availability, FHLB 297,000,000      
Collateralized borrowing availability, Federal Reserve Discount Window 12,000,000      
Carrying value of securities pledged as collateral 174,834,000 142,914,000    
Long-term debt maturity, 2015 5,096,000      
Long-term debt maturity, 2016 35,000,000      
Long-term debt maturity, 2017 15,000,000      
Long-term debt maturity, 2018 20,000,000      
Long-term debt maturity, 2019 5,000,000      
ACNB Bank [Member]        
Debt Instrument [Line Items]        
Line of credit 3,000,000 3,000,000    
Line of credit, balance 0 0    
Securities Sold Under Agreements To Repurchase And Short Term Debt [Member]        
Debt Instrument [Line Items]        
Carrying value of securities pledged as collateral 55,006,000 45,419,000    
CVB Statutory Trust No. 2 [Member]        
Debt Instrument [Line Items]        
Pooled trust preferred debt issuance     7,217,000  
CVB Statutory Trust No. 1 [Member]        
Debt Instrument [Line Items]        
Pooled trust preferred debt issuance       $ 3,093,000