    <SEC-DOCUMENT>0000715579-24-000139-index.html : 20241219
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    <ACCEPTANCE-DATETIME>20241219161325
    ACCESSION NUMBER:		0000715579-24-000139
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		17
    CONFORMED PERIOD OF REPORT:	20241218
    ITEM INFORMATION:		Submission of Matters to a Vote of Security Holders
    ITEM INFORMATION:		Other Events
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20241219
    DATE AS OF CHANGE:		20241219

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			ACNB CORP
    		CENTRAL INDEX KEY:			0000715579
    		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
    		ORGANIZATION NAME:           	02 Finance
    		IRS NUMBER:				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:		241563405

    	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-20241218.htm
    <DESCRIPTION>8-K
    <TEXT>
    Document 1 - file: acnb-20241218.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>pressrelease202419-acnba.htm
    <DESCRIPTION>EX-99.1
    <TEXT>
    Document 2 - file: pressrelease202419-acnba.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>3
    <FILENAME>acnb-20241218.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT
    <TEXT>
    Document 3 - file: acnb-20241218.xsd

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    <SEQUENCE>4
    <FILENAME>acnb-20241218_lab.xml
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    <TEXT>
    Document 4 - file: acnb-20241218_lab.xml

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    <TYPE>EX-101.PRE
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    <FILENAME>acnb-20241218_pre.xml
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    <TEXT>
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    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>pressrelease202419-acnba001.jpg
    <DESCRIPTION>GRAPHIC
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    <SEQUENCE>7
    <FILENAME>pressrelease202419-acnba002.jpg
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    <SEQUENCE>8
    <FILENAME>pressrelease202419-acnba003.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
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    <TYPE>XML
    <SEQUENCE>10
    <FILENAME>R1.htm
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    <TEXT>
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    <DOCUMENT>
    <TYPE>EXCEL
    <SEQUENCE>11
    <FILENAME>Financial_Report.xlsx
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 11 - file: Financial_Report.xlsx

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    <TYPE>XML
    <SEQUENCE>12
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    <TEXT>
    Document 12 - file: Show.js

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    <TYPE>XML
    <SEQUENCE>13
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 13 - file: report.css

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    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>15
    <FILENAME>FilingSummary.xml
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    <TEXT>
    Document 15 - file: FilingSummary.html

    Document 15 - RAW XML: FilingSummary.xml

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    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>17
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    <TEXT>
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    <TYPE>ZIP
    <SEQUENCE>18
    <FILENAME>0000715579-24-000139-xbrl.zip
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    <TYPE>XML
    <SEQUENCE>19
    <FILENAME>acnb-20241218_htm.xml
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