Acquisition of New Windsor Bancorp, Inc.	6 Months Ended
Jun. 30, 2017
Business Combinations [Abstract]
Acquisition of New Windsor Bancorp, Inc.	Acquisition of New Windsor Bancorp, Inc. On November 22, 2016, ACNB announced the execution of the Agreement and Plan of Reorganization (“Reorganization Agreement”) dated November 21, 2016, whereby New Windsor Bancorp, Inc. (“New Windsor”) of Taneytown, Maryland, will be merged with and into an ACNB acquisition subsidiary and, as soon as possible thereafter, New Windsor State Bank, New Windsor’s wholly-owned subsidiary bank, will merge with and into ACNB Bank. Effective July 1, 2017, the Corporation completed the acquisition. At the effective time of the merger, New Windsor was merged with and into a wholly-owned subsidiary of ACNB, immediately followed by the merger of New Windsor State Bank with and into ACNB Bank. ACNB Bank now operates in the Maryland market as “NWSB Bank, A Division of ACNB Bank”. Subject to the terms and conditions of the Reorganization Agreement and at the election of the New Windsor stockholders, at the effective time of the merger, each share of New Windsor common stock was converted into the rights to receive one of the following: (i) 1.10 shares of ACNB common stock or (ii) $30.00 in cash. Such election, however, was subject to allocation and proration procedures such that the number of shares of New Windsor common stock exchanged for ACNB common stock equals 85% of the total number of shares of New Windsor common stock issued and outstanding at the effective time of the merger and the number of shares of New Windsor common stock exchanged for cash equals 15% of the total number of shares of New Windsor common stock issued and outstanding at the effective time of the merger. As a result of New Windsor stockholders’ elections and the related allocation and proration provisions of the Reorganization Agreement, on July 1, 2017, ACNB issued approximately 950,000 shares of its common stock and paid approximately $4,520,000 in cash in the merger. Effective July 1, 2017, in connection with the merger and pursuant to the terms of the Reorganization Agreement, two former New Windsor directors, Todd L. Herring and D. Arthur Seibel, Jr., were appointed as Class 1 and Class 2 Directors, respectively, of ACNB’s Board of Directors. Messrs. Herring and Seibel were also appointed as Directors of ACNB Bank’s Board of Directors. With the combination of the two organizations, ACNB Corporation, on a consolidated basis, will have approximate total assets of $1.6 billion, total deposits of $1.3 billion, and total loans of $1.2 billion. During the three months ended June 30, 2017, merger expenses of $208,000 were incurred for this acquisition. During the six months ended June 30, 2017, merger expenses of $370,000 were incurred for this acquisition. During the year ended December 31, 2016, merger expenses of $472,000 were incurred for this acquisition. In addition, merger-related expenses included in the other expense line items totaled $170,000. The merger transaction was accounted for using the acquisition method of accounting and, accordingly, assets acquired, liabilities assumed, and consideration exchanged were recorded at estimated fair values on the acquisition date. Fair values are preliminary and subject to refinement for up to one year after the closing date of the acquisition. Management is in the process of assessing the assets purchased and liabilities assumed in connection with the merger.

Acquisition of New Windsor Bancorp, Inc.

On November 22, 2016, ACNB announced the execution of the Agreement and Plan of Reorganization (“Reorganization Agreement”) dated November 21, 2016, whereby New Windsor Bancorp, Inc. (“New Windsor”) of Taneytown, Maryland, will be merged with and into an ACNB acquisition subsidiary and, as soon as possible thereafter, New Windsor State Bank, New Windsor’s wholly-owned subsidiary bank, will merge with and into ACNB Bank. Effective July 1, 2017, the Corporation completed the acquisition. At the effective time of the merger, New Windsor was merged with and into a wholly-owned subsidiary of ACNB, immediately followed by the merger of New Windsor State Bank with and into ACNB Bank. ACNB Bank now operates in the Maryland market as “NWSB Bank, A Division of ACNB Bank”.

Subject to the terms and conditions of the Reorganization Agreement and at the election of the New Windsor stockholders, at the effective time of the merger, each share of New Windsor common stock was converted into the rights to receive one of the following: (i) 1.10 shares of ACNB common stock or (ii) $30.00 in cash. Such election, however, was subject to allocation and proration procedures such that the number of shares of New Windsor common stock exchanged for ACNB common stock equals 85% of the total number of shares of New Windsor common stock issued and outstanding at the effective time of the merger and the number of shares of New Windsor common stock exchanged for cash equals 15% of the total number of shares of New Windsor common stock issued and outstanding at the effective time of the merger. As a result of New Windsor stockholders’ elections and the related allocation and proration provisions of the Reorganization Agreement, on July 1, 2017, ACNB issued approximately 950,000 shares of its common stock and paid approximately $4,520,000 in cash in the merger.

Effective July 1, 2017, in connection with the merger and pursuant to the terms of the Reorganization Agreement, two former New Windsor directors, Todd L. Herring and D. Arthur Seibel, Jr., were appointed as Class 1 and Class 2 Directors, respectively, of ACNB’s Board of Directors. Messrs. Herring and Seibel were also appointed as Directors of ACNB Bank’s Board of Directors.

With the combination of the two organizations, ACNB Corporation, on a consolidated basis, will have approximate total assets of $1.6 billion, total deposits of $1.3 billion, and total loans of $1.2 billion. During the three months ended June 30, 2017, merger expenses of $208,000 were incurred for this acquisition. During the six months ended June 30, 2017, merger expenses of $370,000 were incurred for this acquisition. During the year ended December 31, 2016, merger expenses of $472,000 were incurred for this acquisition. In addition, merger-related expenses included in the other expense line items totaled $170,000.

The merger transaction was accounted for using the acquisition method of accounting and, accordingly, assets acquired, liabilities assumed, and consideration exchanged were recorded at estimated fair values on the acquisition date. Fair values are preliminary and subject to refinement for up to one year after the closing date of the acquisition. Management is in the process of assessing the assets purchased and liabilities assumed in connection with the merger.