Business Acquisition, Equity Interest Issued or Issuable, Value Assigned Per Share

No definition available.

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- Definition

Business Combination, Acquired Receivables, Credit Fair Value Adjustments

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Business Combination, Acquired Receivables, Interest Rate Fair Value Adjustments

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Business Combination, Equity Interest Issued or Issuable, Number of Shares Per Shareholder

+ References

No definition available.

+ Details

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- Definition

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Including Goodwill

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Amount of deposits acquired at the acquisition date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of Community Banking Offices, Acquired

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of addition (reduction) to the amount at which an asset could be incurred (settled) in a current transaction between willing parties.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of shares of equity interests issued or issuable to acquire entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the gross contractual amounts receivable, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=121647850&loc=d3e4845-128472

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Costs incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121647850&loc=d3e4845-128472

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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-Name Accounting Standards Codification
-Topic 350
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-Section 45
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of addition (reduction) to the amount at which a liability could be incurred (settled) in a current transaction between willing parties.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
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- Details

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- Details

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Acquisition of Frederick County Bancorp, Inc. - Narrative (Details)		3 Months Ended	6 Months Ended
	Jan. 11, 2020 USD ($) bank $ / shares shares	Jun. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)
Business Acquisition [Line Items]
Goodwill Recorded in Acquisition		$ 42,108,000	$ 42,108,000	$ 19,580,000	$ 19,580,000
Loans receivable, gross amortized cost basis	$ 339,577,000
Interest rate fair value discount	2,600,000
Credit fair value discount	5,300,000
Liabilities, Fair Value Adjustment	$ 854,000
Merger related expenses		0	6,000,000.0
Common Stock
Business Acquisition [Line Items]
Total ACNB shares issued \| shares	1,590,547
Frederick County Bancorp, Inc.
Business Acquisition [Line Items]
Number of community banking offices acquired \| bank	5
Fair value of total assets acquired	$ 443,400,000
Fair value of total loans acquired	329,312,000
Fair value of total deposits acquired	374,100,000
Goodwill Recorded in Acquisition	$ 22,528,000	$ 22,528,000	$ 22,528,000
ACNB's share price for purposes of calculation (in dollars per share) \| $ / shares	$ 36.43
Loans receivable, gross amortized cost basis	$ 339,577,000
Interest rate fair value discount	(2,632,000)
Credit fair value discount	$ (5,931,000)
Frederick County Bancorp, Inc. \| Common Stock
Business Acquisition [Line Items]
Exchange ratio \| shares	0.9900
Total ACNB shares issued \| shares	1,585,597
Investment securities available-for-sale \| Frederick County Bancorp, Inc.
Business Acquisition [Line Items]
Assets, fair value premium	$ 163,000
Time deposits \| Frederick County Bancorp, Inc.
Business Acquisition [Line Items]
Assets, fair value premium	$ 255,000
Core deposit intangibles
Business Acquisition [Line Items]
Amortization period			10 years
Core deposit intangibles \| Frederick County Bancorp, Inc.
Business Acquisition [Line Items]
Amortization period	10 years