    <SEC-DOCUMENT>0001628280-26-010034-index.html : 20260220
    <SEC-HEADER>0001628280-26-010034.hdr.sgml : 20260220
    <ACCEPTANCE-DATETIME>20260220091153
    ACCESSION NUMBER:		0001628280-26-010034
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		22
    CONFORMED PERIOD OF REPORT:	20260219
    ITEM INFORMATION:		Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20260220
    DATE AS OF CHANGE:		20260220

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			ACNB CORP
    		CENTRAL INDEX KEY:			0000715579
    		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
    		ORGANIZATION NAME:           	02 Finance
    		EIN:				232233457
    		STATE OF INCORPORATION:			PA
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-35015
    		FILM NUMBER:		26656871

    	BUSINESS ADDRESS:
    		STREET 1:		16 LINCOLN SQUARE
    		STREET 2:		P O BOX 3129
    		CITY:			GETTYSBURG
    		STATE:			PA
    		ZIP:			17325
    		BUSINESS PHONE:		7173343161

    	MAIL ADDRESS:
    		STREET 1:		P O BOX 3129
    		STREET 2:		16 LINCOLN SQUARE
    		CITY:			GETTYSBURG
    		STATE:			PA
    		ZIP:			17325
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>acnb-20260219.htm
    <DESCRIPTION>8-K
    <TEXT>
    Document 1 - file: acnb-20260219.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>ex991-firstamendmenttoam.htm
    <DESCRIPTION>EX-99.1
    <TEXT>
    Document 2 - file: ex991-firstamendmenttoam.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.2
    <SEQUENCE>3
    <FILENAME>ex992-firstamendmenttoem.htm
    <DESCRIPTION>EX-99.2
    <TEXT>
    Document 3 - file: ex992-firstamendmenttoem.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>4
    <FILENAME>acnb-20260219.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT
    <TEXT>
    Document 4 - file: acnb-20260219.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.LAB
    <SEQUENCE>5
    <FILENAME>acnb-20260219_lab.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION LABEL LINKBASE DOCUMENT
    <TEXT>
    Document 5 - file: acnb-20260219_lab.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.PRE
    <SEQUENCE>6
    <FILENAME>acnb-20260219_pre.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE DOCUMENT
    <TEXT>
    Document 6 - file: acnb-20260219_pre.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>ex991-firstamendmenttoam001.jpg
    <TEXT>
    Document 7 - file: ex991-firstamendmenttoam001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>ex991-firstamendmenttoam002.jpg
    <TEXT>
    Document 8 - file: ex991-firstamendmenttoam002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>ex991-firstamendmenttoam003.jpg
    <TEXT>
    Document 9 - file: ex991-firstamendmenttoam003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>ex991-firstamendmenttoam004.jpg
    <TEXT>
    Document 10 - file: ex991-firstamendmenttoam004.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>ex992-firstamendmenttoem001.jpg
    <TEXT>
    Document 11 - file: ex992-firstamendmenttoem001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>ex992-firstamendmenttoem002.jpg
    <TEXT>
    Document 12 - file: ex992-firstamendmenttoem002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>ex992-firstamendmenttoem003.jpg
    <TEXT>
    Document 13 - file: ex992-firstamendmenttoem003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>ex992-firstamendmenttoem004.jpg
    <TEXT>
    Document 14 - file: ex992-firstamendmenttoem004.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>16
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 16 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>17
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 17 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>18
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 18 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>20
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 20 - file: FilingSummary.html

    Document 20 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>22
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 22 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>23
    <FILENAME>0001628280-26-010034-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 23 - file: 0001628280-26-010034-xbrl.zip

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>24
    <FILENAME>acnb-20260219_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 24 - file: acnb-20260219_htm.html

    Document 24 - RAW XML: acnb-20260219_htm.xml

    </DOCUMENT>
    </SEC-DOCUMENT>