LEASE COMMITMENTS (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Leases [Abstract]
Operating Leases, Rent Expense, Net	$ 456	$ 498	$ 468
Description of Lessee Leasing Arrangements, Operating Leases	ACNB leases space at several of its owned offices to other unrelated organizations under agreements that expired at varying dates in 2015 to 2016.
Operating Leases, Income Statement, Lease Revenue	$ 27	$ 132	$ 138