ACNB (ACNB) 10-Q 3 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 03, 2017
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Entity Registrant Name	ACNB CORP
Entity Central Index Key	715,579
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		7,019,645
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3

CONSOLIDATED STATEMENTS OF COND

CONSOLIDATED STATEMENTS OF CONDITION (UNAUDITED) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
ASSETS
Cash and due from banks	$ 17,882	$ 13,796	$ 13,705
Interest bearing deposits with banks	31,609	5,135	41,686
Total Cash and Cash Equivalents	49,491	18,931	55,391
Securities available for sale	158,392	142,990	143,940
Securities held to maturity, fair value $47,373; $58,566; $55,425	47,369	55,568	57,562
Loans held for sale	1,873	1,770	1,877
Loans, net of allowance for loan losses $14,105; $14,488; $14,194	1,222,265	893,716	857,535
Premises and equipment	26,590	18,153	18,224
Restricted investment in bank stocks	4,821	4,349	4,191
Investment in bank-owned life insurance	44,666	40,742	40,476
Investments in low-income housing partnerships	2,587	2,899	3,003
Goodwill	19,580	6,308	6,308
Intangible assets	2,752	688	774
Foreclosed assets held for resale	275	256	309
Other assets	26,974	19,950	19,279
Total Assets	1,607,635	1,206,320	1,208,869
Deposits:
Non-interest bearing	273,853	180,593	186,035
Interest bearing	1,038,031	787,028	779,512
Total Deposits	1,311,884	967,621	965,547
Short-term borrowings	33,806	34,590	35,503
Long-term borrowings	96,850	74,250	76,500
Other liabilities	11,839	9,798	10,565
Total Liabilities	1,454,379	1,086,259	1,088,115
STOCKHOLDERS’ EQUITY
Preferred stock, $2.50 par value; 20,000,000 shares authorized; no shares outstanding	0	0	0
Common stock, $2.50 par value; 20,000,000 shares authorized; 7,082,245, 6,123,662 and 6,126,738 shares issued; 7,019,645, 6,061,062 and 6,064,138 shares outstanding	17,705	15,317	15,310
Treasury stock, at cost (62,600 shares)	(728)	(728)	(728)
Additional paid-in capital	37,671	10,941	10,849
Retained earnings	103,997	100,555	99,196
Accumulated other comprehensive loss	(5,389)	(6,024)	(3,873)
Total Stockholders’ Equity	153,256	120,061	120,754
Total Liabilities and Stockholders’ Equity	$ 1,607,635	$ 1,206,320	$ 1,208,869

CONSOLIDATED STATEMENTS OF CON3

CONSOLIDATED STATEMENTS OF CONDITION (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Statement of Financial Position [Abstract]
Securities held to maturity, fair value	$ 47,373	$ 55,425	$ 58,566
Allowance for loan losses	$ 14,105	$ 14,194	$ 14,488
Preferred stock, par value (in dollars per share)	$ 2.50	$ 2.50	$ 2.50
Preferred stock, shares authorized	20,000,000	20,000,000	20,000,000
Preferred stock, shares outstanding	0	0	0
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50	$ 2.50
Common stock, shares authorized	20,000,000	20,000,000	20,000,000
Common stock, shares issued	7,082,245	6,126,738	6,123,662
Common stock, shares outstanding	7,019,645	6,064,138	6,061,062
Treasury stock, shares	62,600	62,600	62,600

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
INTEREST INCOME
Loans, including fees	$ 13,990	$ 9,150	$ 33,484	$ 27,054
Securities:
Taxable	890	770	2,474	2,360
Tax-exempt	85	156	352	496
Dividends	61	53	174	159
Other	83	52	120	86
Total Interest Income	15,109	10,181	36,604	30,155
INTEREST EXPENSE
Deposits	1,080	602	2,402	1,730
Short-term borrowings	9	10	69	38
Long-term borrowings	458	384	1,274	1,165
Total Interest Expense	1,547	996	3,745	2,933
Net Interest Income	13,562	9,185	32,859	27,222
PROVISION FOR LOAN LOSSES	0	0	0	0
Net Interest Income after Provision for Loan Losses	13,562	9,185	32,859	27,222
OTHER INCOME
Service charges on deposit accounts	870	631	2,057	1,734
Income from fiduciary activities	489	416	1,409	1,244
Earnings on investment in bank-owned life insurance	276	276	807	834
Gain on sale of premises and equipment	0	0	0	449
Service charges on ATM and debit card transactions	490	381	1,229	1,127
Commissions from insurance sales	1,313	1,269	4,031	3,700
Other	492	328	1,007	896
Total Other Income	3,930	3,301	10,540	9,984
OTHER EXPENSES
Salaries and employee benefits	6,715	5,580	18,397	16,609
Net occupancy	677	481	1,710	1,553
Equipment	1,039	740	2,666	2,212
Other tax	197	201	576	591
Professional services	224	217	807	670
Supplies and postage	187	178	524	491
Marketing and corporate relations	119	123	321	391
FDIC and regulatory	170	181	449	532
Merger related expenses	4,305	0	4,675	0
Intangible assets amortization	193	85	355	259
Foreclosed real estate expenses	35	72	51	112
Other operating	1,006	922	2,970	2,681
Total Other Expenses	14,867	8,780	33,501	26,101
Income before Income Taxes	2,625	3,706	9,898	11,105
PROVISION FOR INCOME TAXES	713	938	2,627	2,808
Net Income	$ 1,912	$ 2,768	$ 7,271	$ 8,297
PER SHARE DATA
Basic earnings (in dollars per share)	$ 0.27	$ 0.46	$ 1.14	$ 1.37
Cash dividends declared (in dollars per share)	$ 0.20	$ 0.20	$ 0.60	$ 0.60

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
NET INCOME		$ 1,912	$ 2,768	$ 7,271	$ 8,297
SECURITIES
Unrealized gains (losses) arising during the period, net of income taxes of $28, $(158), $159 and $265, respectively		54	(308)	306	515
Reclassification adjustment for net gains included in net income, net of income taxes of $0, $0, $0 and $0, respectively	[1],[2]	0	0	0	0
PENSION
Amortization of pension net loss, transition liability, and prior service cost, net of income taxes of $60, $59, $178 and $175, respectively	[2],[3]	109	113	329	338
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		163	(195)	635	853
TOTAL COMPREHENSIVE INCOME		$ 2,075	$ 2,573	$ 7,906	$ 9,150
[1]	Gross amounts are included in net gains on sales or calls of securities on the Consolidated Statements of Income in total other income.
[2]	Income tax amounts are included in the provision for income taxes on the Consolidated Statements of Income.
[3]	Gross amounts are included in the computation of net periodic benefit cost and are included in salaries and employee benefits on the Consolidated Statements of Income in total other expenses.

CONSOLIDATED STATEMENTS OF COM6

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
SECURITIES: Unrealized gains (losses) arising during the period, income taxes	$ 28	$ (158)	$ 159	$ 265
SECURITIES: Reclassification adjustment for net gains included in net income, income taxes	0	0	0	0
PENSION: Amortization of pension net loss, transition liability, and prior service cost, tax	$ 60	$ 59	$ 178	$ 175

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2015	$ 114,715	$ 15,256	$ (728)	$ 10,387	$ 94,526	$ (4,726)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,297				8,297
Other comprehensive income, net of taxes	853					853
Common stock shares issued	338	35		303
Restricted stock grants	119	19		100
Restricted stock compensation expense	59			59
Cash dividends declared	(3,627)				(3,627)
Ending Balance at Sep. 30, 2016	120,754	15,310	(728)	10,849	99,196	(3,873)
Beginning Balance at Dec. 31, 2016	120,061	15,317	(728)	10,941	100,555	(6,024)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,271				7,271
Other comprehensive income, net of taxes	635					635
Common stock shares issued	28,878	2,373		26,505
Restricted stock grants	120	15		105
Restricted stock compensation expense	120			120
Cash dividends declared	(3,829)				(3,829)
Ending Balance at Sep. 30, 2017	$ 153,256	$ 17,705	$ (728)	$ 37,671	$ 103,997	$ (5,389)

CONSOLIDATED STATEMENTS OF CHA8

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Stockholders' Equity [Abstract]
Common stock shares issued (in shares)	949,314	13,903
Restricted stock grants, shares issued (in shares)	6,193	7,435

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 7,271	$ 8,297
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sales of loans originated for sale	(398)	(477)
Gain on sales of foreclosed assets held for resale, including writedowns	(36)	(28)
Gain on sale of premises and equipment	0	(449)
Earnings on investment in bank-owned life insurance	(807)	(834)
Restricted stock compensation expense	120	59
Depreciation and amortization	1,622	1,324
Provision for loan losses	0	0
Net amortization of investment securities premiums	396	391
(Increase) decrease in accrued interest receivable	(637)	29
Increase (decrease) in accrued interest payable	235	(10)
Mortgage loans originated for sale	(21,344)	(29,761)
Proceeds from sales of loans originated for sale	21,639	30,196
Decrease (increase) in other assets	1,051	(887)
Increase in other liabilities	843	966
Net Cash Provided by Operating Activities	9,955	8,816
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from maturities of investment securities held to maturity	8,148	13,809
Proceeds from maturities of investment securities available for sale	18,486	22,334
Purchase of investment securities available for sale	(12,144)	(39,127)
(Purchase) redemption of restricted investment in bank stocks	(136)	223
Net increase in loans	(63,636)	(19,660)
Bank acquisition, net of cash acquired	6,444	0
Capital expenditures	(1,087)	(2,025)
Proceeds from sales of premises and equipment	6	1,929
Proceeds from sales of foreclosed real estate	228	637
Net Cash Used in Investing Activities	(43,691)	(21,880)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in demand deposits	13,254	19,811
Net increase in time certificates of deposits and interest bearing deposits	37,677	32,756
Net (decrease) increase in short-term borrowings	(784)	301
Proceeds from long-term borrowings	24,600	9,000
Repayments on long-term borrowings	(7,000)	(9,000)
Dividends paid	(3,829)	(3,627)
Common stock issued	378	457
Net Cash Provided by Financing Activities	64,296	49,698
Net Increase in Cash and Cash Equivalents	30,560	36,634
CASH AND CASH EQUIVALENTS — BEGINNING	18,931	18,757
CASH AND CASH EQUIVALENTS — ENDING	49,491	55,391
Supplemental disclosures of cash flow information
Interest paid	3,510	2,943
Income taxes paid	2,850	3,200
Loans transferred to foreclosed assets held for resale and other foreclosed transactions	0	338
Increase in assets and liabilities:
Securities	(21,624)	0
Loans	(264,913)	0
Premises and equipment	(8,624)	0
Investment in bank-owned life insurance	(3,118)	0
Restricted investments in bank stocks	(486)	0
Foreclosed assets held for resale	(211)	0
Goodwill	(13,272)	0
Intangibles	(2,418)	0
Other assets	(7,463)	0
Noninterest bearing deposits	80,006	0
Interest bearing deposits	213,327	0
Trust preferred debentures	4,688	0
Other liabilities	1,782	0
Common shares issued	$ 28,620	$ 0

Basis of Presentation and Natur

Basis of Presentation and Nature of Operations	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Nature of Operations	Basis of Presentation and Nature of Operations ACNB Corporation (the Corporation or ACNB), headquartered in Gettysburg, Pennsylvania, is the financial holding company for the wholly-owned subsidiaries of ACNB Bank, Gettysburg, Pennsylvania, and Russell Insurance Group, Inc. (RIG), Westminster, Maryland. ACNB Bank serves its marketplace with banking and trust services via a network of twenty-two retail banking offices located in the four southcentral Pennsylvania counties of Adams, Cumberland, Franklin and York. There is also a loan production office situated in York County, Pennsylvania. On July 1, 2017, ACNB completed its previously announced acquisition of New Windsor Bancorp, Inc. (“NW Bancorp”) of Taneytown, Maryland. At the effective time of the merger, NW Bancorp merged with and into a wholly-owned subsidiary of ACNB, immediately followed by the merger of New Windsor State Bank (“NWSB”) with and into ACNB Bank. ACNB Bank now operates in the Maryland market as “NWSB Bank, A Division of ACNB Bank”. NWSB Bank, a division of ACNB Bank, serves its marketplace with banking and investment services via a network of seven retail banking offices located in Carroll County, Maryland. RIG is a full-service insurance agency based in Westminster, Maryland, with a second location in Germantown, Maryland. The agency offers a broad range of property and casualty, life, and health insurance to both commercial and individual clients. The Corporation’s primary source of revenue is interest income on loans and investment securities and fee income on its products and services. Expenses consist of interest expense on deposits and borrowed funds, provisions for loan losses, and other operating expenses. The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments necessary to present fairly ACNB Corporation’s financial position and the results of operations, comprehensive income, changes in stockholders’ equity, and cash flows. All such adjustments are of a normal recurring nature. The accounting policies followed by the Corporation are set forth in Note A to the Corporation’s consolidated financial statements in the 2016 ACNB Corporation Annual Report on Form 10-K, filed with the SEC on March 15, 2017 . It is suggested that the consolidated financial statements contained herein be read in conjunction with the consolidated financial statements and notes included in the Corporation’s Annual Report on Form 10-K. The results of operations for the three and nine month periods ended September 30, 2017 , are not necessarily indicative of the results to be expected for the full year. The Corporation has evaluated events and transactions occurring subsequent to the statement of condition date of September 30, 2017 , for items that should potentially be recognized or disclosed in the consolidated financial statements. The evaluation was conducted through the date these consolidated financial statements were issued.

Acquisition of New Windsor Banc

Acquisition of New Windsor Bancorp, Inc.	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Acquisition of New Windsor Bancorp, Inc.	Acquisition of New Windsor Bancorp, Inc. On July 1, 2017, ACNB completed its previously-announced acquisition of NW Bancorp of Taneytown, Maryland. NW Bancorp was a locally owned and managed institution with seven locations in north central Maryland that complemented, enhanced and expanded ACNB’s physical presence in north central Maryland. ACNB transacted the merger to enhance its competitive strategic position, potential prospective business opportunities, operations, management, prospective financial condition, future earnings and business prospects. Specifically, ACNB believes that the merger will enhance its business opportunities in Northern Maryland due to the combined company having a greater market share, market presence and the ability to offer more diverse (i.e. Trust Services) and more profitable products, as well as a broader based and geographically diversified branch system to enhance deposit collection and potentially improve funding costs. The fair value of total assets acquired as a result of the merger totaled $319.8 million, loans totaled $263.5 million and deposits totaled $293.3 million. Goodwill recorded in the merger was $13.3 million. In accordance with the terms of the Reorganization Agreement, dated November 21, 2016, as amended, NW Bancorp shareholders received, in aggregate, $4.5 million in cash and 938,360 shares or approximately 13% of the post transaction outstanding shares of the Corporation’s common stock. The transaction was valued at $33.3 million based on the Corporation’s June 30, 2017 closing price of $30.50 as quoted on NASDAQ. The results of the combined entity’s operations are included in the Corporation’s Consolidated Financial Statements from the date of acquisition. The acquisition of NW Bancorp is being accounted for as a business combination using the acquisition method of accounting and, accordingly, assets acquired, liabilities assumed, and consideration paid 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. The following table summarizes the consideration paid for NW Bancorp and the fair value of assets acquired and liabilities assumed as of the acquisition date: Purchase Price Consideration in Common Stock NW Bancorp shares outstanding 1,003,703 Shares paid cash consideration 150,555 Cash consideration (per NW Bancorp share) $ 30.00 Cash portion of purchase price $ 4,519,995 NW Bancorp shares outstanding 1,003,703 Shares paid stock consideration 853,148 Exchange ratio 1.10 Total ACNB shares issued 938,360 ACNB’s share price for purposes of calculation $ 30.50 Equity portion of purchase price $ 28,619,980 Cost of shares owned by buyer $ 150,000 Total consideration paid $ 33,289,975 Allocation of Purchase Price In thousands Total Purchase Price $ 33,290 Fair Value of Assets Acquired Cash and cash equivalents 10,964 Investment securities 21,624 Loans held for sale 1,463 Loans 263,450 Restricted stock 486 Premises and equipment 8,624 Core deposit intangible asset 2,418 Other assets 10,792 Total assets 319,821 Fair Value of Liabilities Assumed Non-interest bearing deposits 80,006 Interest bearing deposits 213,327 Subordinated debt 4,688 Other liabilities 1,782 Total liabilities 299,803 Net Assets Acquired 20,018 Goodwill Recorded in Merger $ 13,272 Pursuant to the accounting requirements, the Corporation assigned a fair value to the assets acquired and liabilities assumed of NW Bancorp. ASC 820 defines fair value as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The calculation of goodwill is subject to change for up to one year after the date of acquisition as additional information relative to the closing date estimates and uncertainties become available. Goodwill and core deposit intangibles are allocated to the banking business segment. Fair values of the major categories of assets acquired and liabilities assumed were determined as follows: Investment securities available-for-sale The estimated fair values of the investment securities available for sale, primarily comprised of U.S. Government agency mortgage-backed securities, U.S. government agencies and municipal bonds, were determined using Level 2 inputs in the fair value hierarchy. The fair values were determined using independent pricing services. The Corporation’s independent pricing service utilized matrix pricing, which is a mathematical technique used widely in the industry to value debt securities without relying exclusively on quoted market prices for the specific security but rather relying on the security’s relationship to other benchmark quoted prices. Management reviewed the data and assumptions used in pricing the securities. A fair value premium of $361,000 was recorded and will be amortized over the estimated life of the investments using the interest rate method. Loans Acquired loans (impaired and non-impaired) are initially recorded at their acquisition-date fair values using Level 3 inputs. Fair values are based on a discounted cash flow methodology that involves assumptions and judgments as to credit risk, expected life time losses, environmental factors, collateral values, discount rates, expected payments and expected prepayments. Specifically, the Corporation has prepared three separate loan fair value adjustments that it believed a market participant might employ in estimating the entire fair value adjustment necessary under ASC 820-10 for the acquired loan portfolio. The three-separate fair valuation methodology employed are: 1) an interest rate loan fair value adjustment (analysis available at request of the Corporation), 2) a general credit fair value adjustment (analysis available at request of the Corporation), and 3) a specific credit fair value adjustment for purchased credit impaired loans subject to ASC 310-30 procedures. The acquired loans were recorded at fair value at the acquisition date without carryover of NWSB’s previously established allowance for loan losses. The fair value of the financial assets acquired included loans receivable with a gross amortized cost basis of $272,646,000 . The table below illustrates the fair value adjustments made to the amortized cost basis in order to present a fair value of the loans acquired. The credit adjustment on purchased credit impaired loans is derived in accordance with ASC 310-30 and represents the portion of the loan balances that has been deemed uncollectible based on the Corporation’s expectations of future cash flows for each respective loan. In thousands Gross amortized cost basis at July 1, 2017 $ 272,646 Interest rate fair value adjustment on pools of homogeneous loans (731 ) Credit fair value adjustment on pools of homogeneous loans (4,501 ) Credit fair value adjustment on purchased credit impaired loans (3,964 ) Fair value of acquired loans at July 1, 2017 $ 263,450 For loans acquired without evidence of credit quality deterioration, ACNB prepared the interest rate loan fair value and credit fair value adjustments. Loans were grouped into homogeneous pools by characteristics such as loan type, term, collateral and rate. Market rates for similar loans were obtained from various internal and external data sources and reviewed by management for reasonableness. The average of these rates was used as the fair value interest rate a market participant would utilize. A present value approach was utilized to calculate the interest rate fair value discount of $731,000 . Additionally for loans acquired without credit deterioration, a credit fair value adjustment was calculated using a two-part credit fair value analysis: 1) expected lifetime credit migration losses; and 2) estimated fair value adjustment for certain qualitative factors. The expected lifetime losses were calculated using historical losses observed at the Bank, NWSB and peer banks. ACNB also estimated an environmental factor to apply to each loan type. The environmental factor represents potential discount which may arise due to general credit and economic factors. A credit fair value discount of $4.5 million was determined. Both the interest rate and credit fair value adjustments relate to loans acquired with evidence of credit quality deterioration will be substantially recognized as interest income on a level yield amortization method over the expected life of the loans. The following table presents the acquired purchased credit impaired loans receivable at the Acquisition Date: In thousands Contractual principal and interest at acquisition $ 13,439 Nonaccretable difference (5,651 ) Expected cash flows at acquisition 7,788 Accretable yield (1,458 ) Fair value of purchased impaired loans $ 6,330 Bank Premises The Corporation acquired seven branches of NWSB. The fair value of NWSB’s premises, including land, buildings, and improvements, was determined based upon independent third-party appraisals performed by licensed appraisers in the market in which the premises are located. The Corporation prepared an internal analysis to compare the lease contract obligations to comparable market rental rates. The Corporation believed that the leased contract rates were in a reasonable range of market rental rates and concluded that no fair market value adjustment related to leasehold interest was necessary. Core Deposit Intangible The fair value of the core deposit intangible was determined based on a discounted cash flow analysis using a discount rate commensurate with market participants. To calculate cash flows, deposit account servicing costs (net of deposit fee income) and interest expense on deposits were compared to the cost of alternative funding sources available through national brokered CD offering rates. The projected cash flows were developed using projected deposit attrition rates. The core deposit intangible will be amortized over ten years using the sum-of-years digits method. Time Deposits The fair value adjustment for time deposits represents a discount from the value of the contractual repayments of fixed-maturity deposits using prevailing market interest rates for similar-term time deposits. The time deposit discount of approximately $847,500 is being amortized into income on a level yield amortization method over the contractual life of the deposits. Long-term Borrowings The Corporation assumed a trust preferred subordinated debt in connection with the merger. The fair value of the trust preferred subordinated debt was determined based upon an estimated fair value from an independent brokerage firm. The trust preferred capital note was valued at discount of $312,500 , which is being amortized into income on a level yield amortization method based upon the assumed market rate, and the term of the trust preferred subordinated debt instrument. The following table presents certain pro forma information as if NWSB had been acquired on December 31, 2016. These results combine the historical results of the Corporation in the Corporation’s Consolidated Statements of Income and, while certain adjustments were made for the estimated impact of certain fair value adjustments and other acquisition-related activity, they are not indicative of what would have occurred had the acquisition taken place on December 31, 2016. In particular, no adjustments have been made to eliminate the amount of NWSB’s provision for loan losses that would not have been necessary had the acquired loans been recorded at fair value as of December 31, 2016. The Corporation expects to achieve further operating cost savings and other business synergies as a result of the acquisition which are not reflected in the pro forma amounts below: In thousands For the Year Ended December 31, 2016 Total revenues (net interest income plus noninterest income) $ 102,891 Net Income 13,591 Acquisition-related expenses associated with the acquisition of NWSB were $4.3 million for the three months ended September 30, 2017 and $4.7 million for the nine months ended September 30, 2017. Such costs include legal and accounting fees, lease and contract termination expenses, system conversion, operations integration, and employee severances, which have been expensed as incurred.

Earnings Per Share and Restrict

Earnings Per Share and Restricted Stock Plan	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share and Restricted Stock Plan	Earnings Per Share and Restricted Stock Plan The Corporation has a simple capital structure. Basic earnings per share of common stock is computed based on 6,383,149 and 6,048,216 weighted average shares of common stock outstanding for the nine months ended September 30, 2017 and 2016 , respectively, and 7,004,346 and 6,057,508 for the three months ended September 30, 2017 and 2016 , respectively. All outstanding unvested restricted stock awards that contain rights to nonforfeitable dividends are considered participating securities for this calculation. The Corporation has a restricted stock plan available to selected officers and employees of the Bank to advance the best interest of the Corporation and its shareholders. The plan provides those persons who have responsibility for its growth with additional incentive by allowing them to acquire ownership in the Corporation and, thereby, encouraging them to contribute to the success of the Corporation. Plan expense is recognized over the vesting period of the stock issued under the plan. As of September 30, 2017 , 19,301 shares were issued under this plan, of which 12,693 were fully vested and the remaining 6,608 will vest over the next year. $120,000 and $59,000 of compensation expenses related to the grants were recognized during the nine months ended September 30, 2017 and 2016, respectively. No compensation expenses were recognized during the three months ended September 30, 2017 or 2016.

Retirement Benefits

Retirement Benefits	9 Months Ended
	Sep. 30, 2017
Postemployment Benefits [Abstract]
Retirement Benefits	Retirement Benefits The components of net periodic benefit expense related to the non-contributory, defined benefit pension plan for the three and nine month periods ended September 30 were as follows: Three Months Ended September 30, Nine Months Ended September 30 In thousands 2017 2016 2017 2016 Service cost $ 210 $ 199 $ 630 $ 597 Interest cost 284 284 852 852 Expected return on plan assets (630 ) (609 ) (1,890 ) (1,824 ) Amortization of net loss 169 172 507 513 Net Periodic Benefit Expense $ 33 $ 46 $ 99 $ 138 The Corporation previously disclosed in its consolidated financial statements for the year ended December 31, 2016 , that it had not yet determined the amount the Bank planned on contributing to the defined benefit plan in 2017 . As of September 30, 2017 , this contribution amount had still not been determined. Effective April 1, 2012, no inactive or former participant in the plan is eligible to again participate in the plan, and no employee hired after March 31, 2012, is eligible to participate in the plan. As of the last annual census, ACNB Bank had a combined 358 active, vested, terminated and retired persons in the plan.

Guarantees

Guarantees	9 Months Ended
	Sep. 30, 2017
Guarantees [Abstract]
Guarantees	Guarantees The Corporation does not issue any guarantees that would require liability recognition or disclosure, other than its standby letters of credit. Standby letters of credit are written conditional commitments issued by the Corporation to guarantee the performance of a customer to a third party. Generally, all letters of credit, when issued, have expiration dates within one year . The credit risk involved in issuing letters of credit is essentially the same as those that are involved in extending loan facilities to customers. The Corporation generally holds collateral and/or personal guarantees supporting these commitments. The Corporation had $6,974,000 in standby letters of credit as of September 30, 2017 . Management believes that the proceeds obtained through a liquidation of collateral and the enforcement of guarantees would be sufficient to cover the potential amount of future payments required under the corresponding guarantees. The current amount of the liability, as of September 30, 2017 , for guarantees under standby letters of credit issued is not material.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity Note [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss The components of accumulated other comprehensive loss, net of taxes, are as follows: In thousands Unrealized Gains (Losses) on Securities Pension Liability Accumulated Other Comprehensive Loss BALANCE — SEPTEMBER 30, 2017 $ 40 $ (5,429 ) $ (5,389 ) BALANCE — DECEMBER 31, 2016 $ (266 ) $ (5,758 ) $ (6,024 ) BALANCE — SEPTEMBER 30, 2016 $ 1,679 $ (5,552 ) $ (3,873 )

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Corporation has two reporting segments, the Bank and RIG. RIG is managed separately from the banking segment, which includes the Bank and related financial services that the Corporation offers through its banking subsidiary. RIG offers a broad range of property and casualty, life, and health insurance to both commercial and individual clients. Segment information for the nine month periods ended September 30, 2017 and 2016 , is as follows: In thousands Banking Insurance Total 2017 Net interest income and other income from external customers $ 39,536 $ 3,863 $ 43,399 Income before income taxes 9,099 799 9,898 Total assets 1,598,331 9,304 1,607,635 Capital expenditures 1,087 — 1,087 2016 Net interest income and other income from external customers $ 33,871 $ 3,335 $ 37,206 Income before income taxes 10,424 681 11,105 Total assets 1,199,365 9,504 1,208,869 Capital expenditures 2,013 12 2,025 Segment information for the three month periods ended September 30, 2017 and 2016 , is as follows: In thousands Banking Insurance Total 2017 Net interest income and other income from external customers $ 16,321 $ 1,171 $ 17,492 Income before income taxes 2,424 201 2,625 Total assets 1,598,331 9,304 1,607,635 Capital expenditures 284 — 284 2016 Net interest income and other income from external customers $ 11,581 $ 905 $ 12,486 Income before income taxes 3,485 221 3,706 Total assets 1,199,365 9,504 1,208,869 Capital expenditures 326 — 326 Customer lists intangible assets are amortized over 10 years on a straight line basis. Core deposit intangible assets are amortized over 10 years using the sum-of-years digits method. Goodwill is not amortized, but rather is analyzed annually for impairment. If certain events occur which might indicate goodwill has been impaired, the goodwill is tested for impairment when such events occur. Tax amortization of goodwill and the intangible assets is deductible for tax purposes. Tax amortization of the goodwill associated with the NW acquisition is not deductible for federal income tax purposes.

Securities

Securities	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Securities	Securities Debt securities that management has the positive intent and ability to hold to maturity are classified as “held to maturity” and recorded at amortized cost. Securities not classified as held to maturity or trading, including equity securities with readily determinable fair values, are classified as “available for sale” and recorded at fair value, with unrealized gains and losses excluded from earnings and reported, net of tax, in other comprehensive income (loss). Purchase premiums and discounts are recognized in interest income using the interest method over the terms of the securities. Declines in the fair value of held to maturity and available for sale securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses. In estimating other-than-temporary impairment losses on debt securities, management considers (1) whether management intends to sell the security, or (2) if it is more likely than not that management will be required to sell the security before recovery, or (3) if management does not expect to recover the entire amortized cost basis. In assessing potential other-than-temporary impairment for equity securities, consideration is given to management’s intention and ability to hold the securities until recovery of unrealized losses. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. Amortized cost and fair value of securities at September 30, 2017 , and December 31, 2016 , were as follows: In thousands Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value SECURITIES AVAILABLE FOR SALE SEPTEMBER 30, 2017 U.S. Government and agencies $ 99,999 $ 37 $ 1,022 $ 99,014 Mortgage-backed securities, residential 36,673 705 27 37,351 State and municipal 14,967 160 11 15,116 Corporate bonds 5,000 112 — 5,112 CRA mutual fund 1,044 — 2 1,042 Stock in other banks 647 110 — 757 $ 158,330 $ 1,124 $ 1,062 $ 158,392 DECEMBER 31, 2016 U.S. Government and agencies $ 81,065 $ 43 $ 1,529 $ 79,579 Mortgage-backed securities, residential 31,272 782 81 31,973 State and municipal 24,514 240 94 24,660 Corporate bonds 5,000 62 — 5,062 CRA mutual fund 1,044 — 9 1,035 Stock in other banks 498 183 — 681 $ 143,393 $ 1,310 $ 1,713 $ 142,990 SECURITIES HELD TO MATURITY SEPTEMBER 30, 2017 U.S. Government and agencies $ 20,004 $ 25 $ 54 $ 19,975 Mortgage-backed securities, residential 27,365 156 123 27,398 $ 47,369 $ 181 $ 177 $ 47,373 DECEMBER 31, 2016 U.S. Government and agencies $ 23,017 $ 26 $ 54 $ 22,989 Mortgage-backed securities, residential 32,551 210 325 32,436 $ 55,568 $ 236 $ 379 $ 55,425 The following table shows the Corporation’s investments’ gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at September 30, 2017 , and December 31, 2016 : Less than 12 Months 12 Months or More Total In thousands Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses SECURITIES AVAILABLE FOR SALE SEPTEMBER 30, 2017 U.S. Government and agencies $ 65,649 $ 629 $ 15,756 $ 393 $ 81,405 $ 1,022 Mortgage-backed securities, residential 6,783 27 — — 6,783 27 State and municipal 1,441 7 691 4 2,132 11 CRA Mutual Fund 1,042 2 — — 1,042 2 $ 74,915 $ 665 $ 16,447 $ 397 $ 91,362 $ 1,062 DECEMBER 31, 2016 U.S. Government and agencies $ 71,454 $ 1,529 $ — $ — $ 71,454 $ 1,529 Mortgage-backed securities, residential 8,966 81 — — 8,966 81 State and municipal 4,933 94 — — 4,933 94 CRA Mutual Fund 1,035 9 — — 1,035 9 $ 86,388 $ 1,713 $ — $ — $ 86,388 $ 1,713 SECURITIES HELD TO MATURITY SEPTEMBER 30, 2017 U.S. Government and agencies $ 12,948 $ 52 $ 1,998 $ 2 $ 14,946 $ 54 Mortgage-backed securities, residential 10,496 114 1,168 9 11,664 123 $ 23,444 $ 166 $ 3,166 $ 11 $ 26,610 $ 177 DECEMBER 31, 2016 U.S. Government and agencies $ 12,946 $ 54 $ — $ — $ 12,946 $ 54 Mortgage-backed securities, residential 12,956 325 — — 12,956 325 $ 25,902 $ 379 $ — $ — $ 25,902 $ 379 All mortgage-backed security investments are government sponsored enterprise (GSE) pass-through instruments issued by the Federal National Mortgage Association (FNMA), Government National Mortgage Association (GNMA) or Federal Home Loan Mortgage Corporation (FHLMC), which guarantee the timely payment of principal on these investments. At September 30, 2017 , fifty-six available for sale U.S. Government and agency securities had unrealized losses that individually did not exceed 4% of amortized cost. Nine of these securities have been in a continuous loss position for 12 months or more. These unrealized losses relate principally to changes in interest rates subsequent to the acquisition of the specific securities. At September 30, 2017 , eight available for sale residential mortgage-backed securities had unrealized losses that individually did not exceed 1% of amortized cost. These securities have not been in a continuous loss position for 12 months or more. These unrealized losses relate principally to changes in interest rates subsequent to the acquisition of the specific securities. At September 30, 2017 , nine available for sale state and municipal securities had unrealized losses that individually did not exceed 2% of amortized cost. Three of these securities have been in a continuous loss position for 12 months or more. These unrealized losses relate principally to changes in interest rates subsequent to the acquisition of the specific securities. At September 30, 2017 , the CRA Mutual Fund had an unrealized loss that did not exceed 1% of amortized cost. This security has not been in a continuous loss position for 12 months or more. This unrealized loss relates principally to changes in interest rates subsequent to the acquisition of the specific security. At September 30, 2017 , eight held to maturity U.S. Government and agency securities had unrealized losses that individually did not exceed 1% of amortized cost. One of these securities has been in a continuous loss position for 12 months or more. These unrealized losses relate principally to changes in interest rates subsequent to the acquisition of the specific securities. At September 30, 2017 , thirteen held to maturity residential mortgage-backed securities had unrealized losses that individually did not exceed 2% of amortized cost. One of these securities has been in a continuous loss position for 12 months or more. These unrealized losses relate principally to changes in interest rates subsequent to the acquisition of the specific securities. In analyzing the issuer’s financial condition, management considers industry analysts’ reports, financial performance, and projected target prices of investment analysts within a one-year time frame. Based on the above information, management has determined that none of these investments are other-than-temporarily impaired. The fair values of securities available for sale (carried at fair value) and held to maturity (carried at amortized cost) are determined by obtaining quoted market prices on nationally recognized securities exchanges (Level 1), or matrix pricing (Level 2) which is a mathematical technique used widely in the industry to value debt securities without relying exclusively on quoted market prices for the specific securities but rather by relying on the security’s relationship to other benchmark quoted prices. The Corporation uses independent service providers to provide matrix pricing. Management routinely sells securities from its available for sale portfolio in an effort to manage and allocate the portfolio. At September 30, 2017 , management had not identified any securities with an unrealized loss that it intends to sell or will be required to sell. In estimating other-than-temporary impairment losses on debt securities, management considers (1) whether management intends to sell the security, or (2) if it is more likely than not that management will be required to sell the security before recovery, or (3) if management does not expect to recover the entire amortized cost basis. In assessing potential other-than-temporary impairment for equity securities, consideration is given to management’s intention and ability to hold the securities until recovery of unrealized losses. Amortized cost and fair value at September 30, 2017 , by contractual maturity, where applicable, are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay with or without penalties. Available for Sale Held to Maturity In thousands Amortized Cost Fair Value Amortized Cost Fair Value 1 year or less $ 6,576 $ 6,589 $ 8,004 $ 7,998 Over 1 year through 5 years 97,681 96,972 12,000 11,977 Over 5 years through 10 years 15,709 15,681 — — Over 10 years — — — — Mortgage-backed securities, residential 36,673 37,351 27,365 27,398 CRA mutual fund 1,044 1,042 — — Stock in other banks 647 757 — — $ 158,330 $ 158,392 $ 47,369 $ 47,373 The Corporation did not sell any securities available for sale during the three and nine months ended September 30, 2017 and 2016 . At September 30, 2017 , and December 31, 2016 , securities with a carrying value of $177,259,000 and $134,763,000 , respectively, were pledged as collateral as required by law on public and trust deposits, repurchase agreements, and for other purposes.

Loans

Loans	9 Months Ended
	Sep. 30, 2017
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Loans	Loans The Corporation grants commercial, residential, and consumer loans to customers. A substantial portion of the loan portfolio is represented by mortgage loans throughout southcentral Pennsylvania and northern Maryland. The ability of the Corporation’s debtors to honor their contracts is dependent upon the real estate values and general economic conditions in this area. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off generally are reported at their outstanding unpaid principal balances adjusted for charge-offs, the allowance for loan losses, and any deferred fees or costs on originated loans. Interest income is accrued on the unpaid principal balance. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the related loan yield using the interest method. The loans receivable portfolio is segmented into commercial, residential mortgage, home equity lines of credit, and consumer loans. Commercial loans consist of the following classes: commercial and industrial, commercial real estate, and commercial real estate construction. The accrual of interest on residential mortgage and commercial loans is discontinued at the time the loan is 90 days past due unless the credit is well-secured and in process of collection. Consumer loans (consisting of home equity lines of credit and consumer loan classes) are typically charged off no later than 120 days past due. Past due status is based on the contractual terms of the loan. In all cases, loans are placed on nonaccrual or charged off at an earlier date if collection of principal or interest is considered doubtful. All interest accrued, but not collected, for loans that are placed on nonaccrual or charged off is reversed against interest income. The interest on these loans is accounted for on the cash-basis or cost-recovery method, until qualifying for return to accrual status. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. Allowance for Credit Losses The allowance for credit losses consists of the allowance for loan losses and the reserve for unfunded lending commitments. The allowance for loan losses (the “allowance”) is established as losses are estimated to occur through a provision for loan losses charged to earnings. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The reserve for unfunded lending commitments represents management’s estimate of losses inherent in its unfunded loan commitments and is recorded in other liabilities on the consolidated statement of condition. The amount of the reserve for unfunded lending commitments is not material to the consolidated financial statements. The allowance for loan losses is evaluated on a regular basis by management and is based upon management’s periodic review of the collectibility of the loans in light of historical experience, the nature and volume of the loan portfolio, adverse situations that may affect the borrower’s ability to repay, estimated value of any underlying collateral, and prevailing economic conditions. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available. The allowance consists of specific, general and unallocated components. The specific component relates to loans that are classified as either doubtful, substandard, or special mention. For such loans that are also classified as impaired, an allowance is established when the discounted cash flows (or collateral value or observable market price) of the impaired loan is lower than the carrying value of that loan. The general component covers pools of loans by loan class including commercial loans not considered impaired, as well as smaller balance homogeneous loans, such as residential real estate, home equity, and other consumer loans. These pools of loans are evaluated for loss exposure based upon historical loss rates for the previous twelve quarters for each of these categories of loans, adjusted for qualitative risk factors. These qualitative risk factors include: • lending policies and procedures, including underwriting standards and collection, charge-off and recovery practices; • national, regional and local economic and business conditions, as well as the condition of various market segments, including the impact on the value of underlying collateral for collateral dependent loans; • the nature and volume of the portfolio and terms of loans; • the experience, ability and depth of lending management and staff; • the volume and severity of past due, classified and nonaccrual loans, as well as other loan modifications; and, • the existence and effect of any concentrations of credit and changes in the level of such concentrations. Each factor is assigned a value to reflect improving, stable or declining conditions based on management’s best judgment using relevant information available at the time of the evaluation. Adjustments to the factors are supported through documentation of changes in conditions in a narrative accompanying the allowance for loan loss calculation. The unallocated component of the allowance is maintained to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance reflects the margin of imprecision inherent in the underlying assumptions used in the methodologies for estimating specific and general losses in the portfolio. It covers risks that are inherently difficult to quantify including, but not limited to, collateral risk, information risk, and historical charge-off risk. A loan is considered impaired when, based on current information and events, it is probable that the Corporation will be unable to collect the scheduled payments of principal and/or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and/or interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan by loan basis for commercial and commercial construction loans by either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral if the loan is collateral dependent. A specific allocation within the allowance for loan losses is established for an impaired loan if its carrying value exceeds its estimated fair value. The estimated fair values of the Corporation’s impaired loans are measured based on the estimated fair value of the loan’s collateral or the discounted cash flows method. It is the policy of the Corporation to order an updated valuation on all real estate secured loans when the loan becomes 90 days past due and there has not been an updated valuation completed within the previous 12 months. In addition, the Corporation orders third-party valuations on all impaired real estate collateralized loans within 30 days of the loan being classified as impaired. Until the valuations are completed, the Corporation utilizes the most recent independent third-party real estate valuation to estimate the need for a specific allocation to be assigned to the loan. These existing valuations are discounted downward to account for such things as the age of the existing collateral valuation, change in the condition of the real estate, change in local market and economic conditions, and other specific factors involving the collateral. Once the updated valuation is completed, the collateral value is updated accordingly. For commercial and industrial loans secured by non-real estate collateral, such as accounts receivable, inventory and equipment, estimated fair values are determined based on the borrower’s financial statements, inventory reports, accounts receivable aging reports, equipment appraisals, or invoices. Indications of value from these sources are generally discounted based on the age of the financial information or the quality of the assets. The Corporation actively monitors the values of collateral as well as the age of the valuation of impaired loans. Management believes that the Corporation’s market area is not as volatile as other areas throughout the United States, therefore valuations are ordered at least every 18 months , or more frequently if management believes that there is an indication that the fair value has declined. For impaired loans secured by collateral other than real estate, the Corporation considers the net book value of the collateral, as recorded in the most recent financial statements of the borrower, and determines fair value based on estimates made by management. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Corporation does not separately identify individual consumer and residential loans for impairment disclosures, unless such loans are the subject of a troubled debt restructure. Loans whose terms are modified are classified as troubled debt restructured loans if the Corporation grants such borrowers concessions that it would not otherwise consider and it is deemed that those borrowers are experiencing financial difficulty. Concessions granted under a troubled debt restructuring generally involve a temporary reduction in interest rate, a below market interest rate given the risk associated with the loan, or an extension of a loan’s stated maturity date. Nonaccrual troubled debt restructurings may be restored to accrual status if principal and interest payments, under the modified terms, are current for a sustained period of time and, based on a well-documented credit evaluation of the borrower’s financial condition, there is reasonable assurance of repayment. Loans classified as troubled debt restructurings are generally designated as impaired. The allowance calculation methodology includes further segregation of loan classes into credit quality rating categories. The borrower’s overall financial condition, repayment sources, guarantors, and value of collateral, if appropriate, are generally evaluated annually for commercial loans or when credit deficiencies arise, such as delinquent loan payments. Credit quality risk ratings include regulatory classifications of special mention, substandard, doubtful, and loss. Loans classified special mention have potential weaknesses that deserve management’s close attention. If uncorrected, the potential weaknesses may result in deterioration of the repayment prospects. Loans classified substandard have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They include loans that are inadequately protected by the current sound net worth and paying capacity of the obligor or of the collateral pledged, if any. Loans classified doubtful have all the weaknesses inherent in loans classified substandard with the added characteristic that collection or liquidation in full, on the basis of current conditions and facts, is highly improbable. Loans classified as a loss are considered uncollectible and are charged to the allowance for loan losses. Loans not classified are rated pass. In addition, federal and state regulatory agencies, as an integral part of their examination process, periodically review the Corporation’s allowance for loan losses and may require the Corporation to recognize additions to the allowance based on their judgments about information available to them at the time of their examination, which may not be currently available to management. Based on management’s comprehensive analysis of the loan portfolio and economic conditions, management believes the current level of the allowance for loan losses is adequate. Commercial and Industrial Lending — The Corporation originates commercial and industrial loans primarily to businesses located in its primary market area and surrounding areas. These loans are used for various business purposes which include short-term loans and lines of credit to finance machinery and equipment purchases, inventory, and accounts receivable. Generally, the maximum term for loans extended on machinery and equipment is based on the projected useful life of such machinery and equipment. Most business lines of credit are written on demand and may be renewed annually. Commercial and industrial loans are generally secured with short-term assets; however, in many cases, additional collateral such as real estate is provided as additional security for the loan. Loan-to-value maximum values have been established by the Corporation and are specific to the type of collateral. Collateral values may be determined using invoices, inventory reports, accounts receivable aging reports, collateral appraisals, etc. In underwriting commercial and industrial loans, an analysis is performed to evaluate the borrower’s character and capacity to repay the loan, the adequacy of the borrower’s capital and collateral, as well as the conditions affecting the borrower. Evaluation of the borrower’s past, present and future cash flows is also an important aspect of the Corporation’s analysis. Commercial loans generally present a higher level of risk than other types of loans due primarily to the effect of general economic conditions. Commercial Real Estate Lending — The Corporation engages in commercial real estate lending in its primary market area and surrounding areas. The Corporation’s commercial loan portfolio is secured primarily by commercial retail space, office buildings, and hotels. Generally, commercial real estate loans have terms that do not exceed 20 years, have loan-to-value ratios of up to 80% of the appraised value of the property, and are typically secured by personal guarantees of the borrowers. In underwriting these loans, the Corporation performs a thorough analysis of the financial condition of the borrower, the borrower’s credit history, and the reliability and predictability of the cash flow generated by the property securing the loan. Appraisals on properties securing commercial real estate loans originated by the Corporation are performed by independent appraisers. Commercial real estate loans generally present a higher level of risk than other types of loans due primarily to the effect of general economic conditions and the complexities involved in valuing the underlying collateral. Commercial Real Estate Construction Lending — The Corporation engages in commercial real estate construction lending in its primary market area and surrounding areas. The Corporation’s commercial real estate construction lending consists of commercial and residential site development loans, as well as commercial building construction and residential housing construction loans. The Corporation’s commercial real estate construction loans are generally secured with the subject property. Terms of construction loans depend on the specifics of the project, such as estimated absorption rates, estimated time to complete, etc. In underwriting commercial real estate construction loans, the Corporation performs a thorough analysis of the financial condition of the borrower, the borrower’s credit history, and the reliability and predictability of the cash flow generated by the project using feasibility studies, market data, etc. Appraisals on properties securing commercial real estate construction loans originated by the Corporation are performed by independent appraisers. Commercial real estate construction loans generally present a higher level of risk than other types of loans due primarily to the effect of general economic conditions and the uncertainties surrounding total construction costs. Residential Mortgage Lending — One-to-four family residential mortgage loan originations, including home equity closed-end loans, are generated by the Corporation’s marketing efforts, its present customers, walk-in customers, and referrals. These loans originate primarily within the Corporation’s market area or with customers primarily from the market area. The Corporation offers fixed-rate and adjustable-rate mortgage loans with terms up to a maximum of 30 years for both permanent structures and those under construction. The Corporation’s one-to-four family residential mortgage originations are secured primarily by properties located in its primary market area and surrounding areas. The majority of the Corporation’s residential mortgage loans originate with a loan-to-value of 80% or less. Loans in excess of 80% are required to have private mortgage insurance. In underwriting one-to-four family residential real estate loans, the Corporation evaluates both the borrower’s financial ability to repay the loan as agreed and the value of the property securing the loan. Properties securing real estate loans made by the Corporation are appraised by independent appraisers. The Corporation generally requires borrowers to obtain an attorney’s title opinion or title insurance, as well as fire and property insurance (including flood insurance, if necessary) in an amount not less than the amount of the loan. The Corporation has not engaged in subprime residential mortgage originations. Residential mortgage loans present a moderate level of risk due primarily to general economic conditions, as well as a continued weak housing market. Home Equity Lines of Credit Lending — The Corporation originates home equity lines of credit primarily within the Corporation’s market area or with customers primarily from the market area. Home equity lines of credit are generated by the Corporation’s marketing efforts, its present customers, walk-in customers, and referrals. Home equity lines of credit are secured by the borrower’s primary residence with a maximum loan-to-value of 90% and a maximum term of 20 years. In underwriting home equity lines of credit, the Corporation evaluates both the value of the property securing the loan and the borrower’s financial ability to repay the loan as agreed. The ability to repay is determined by the borrower’s employment history, current financial condition, and credit background. Home equity lines of credit generally present a moderate level of risk due primarily to general economic conditions, as well as a continued weak housing market. Junior liens inherently have more credit risk by virtue of the fact that another financial institution may have a higher security position in the case of foreclosure liquidation of collateral to extinguish the debt. Generally, foreclosure actions could become more prevalent if the real estate market continues to be weak and property values deteriorate. Consumer Lending — The Corporation offers a variety of secured and unsecured consumer loans, including those for vehicles and mobile homes and loans secured by savings deposits. These loans originate primarily within the Corporation’s market area or with customers primarily from the market area. Consumer loan terms vary according to the type and value of collateral and the creditworthiness of the borrower. In underwriting consumer loans, a thorough analysis of the borrower’s financial ability to repay the loan as agreed is performed. The ability to repay is determined by the borrower’s employment history, current financial condition, and credit background. Consumer loans may entail greater credit risk than residential mortgage loans or home equity lines of credit, particularly in the case of consumer loans which are unsecured or are secured by rapidly depreciable assets such as automobiles or recreational equipment. In such cases, any repossessed collateral for a defaulted consumer loan may not provide an adequate source of repayment of the outstanding loan balance as a result of the greater likelihood of damage, loss or depreciation. In addition, consumer loan collections are dependent on the borrower’s continuing financial stability, and thus are more likely to be affected by adverse personal circumstances. Furthermore, the application of various federal and state laws, including bankruptcy and insolvency laws, may limit the amount which can be recovered on such loans. Acquired Loans Acquired loans (impaired and non-impaired) are initially recorded at their acquisition-date fair values using Level 3 inputs. Fair values are based on a discounted cash flow methodology that involves assumptions and judgments as to credit risk, expected life time losses, environmental factors, collateral values, discount rates, expected payments and expected prepayments. Specifically, the Corporation has prepared three separate loan fair value adjustments that it believed a market participant might employ in estimating the entire fair value adjustment necessary under ASC 820-10 for the acquired loan portfolio. The three-separate fair valuation methodology employed are: 1) an interest rate loan fair value adjustment (analysis available at request of the Corporation), 2) a general credit fair value adjustment (analysis available at request of the Corporation), and 3) a specific credit fair value adjustment for purchased credit impaired loans subject to ASC 310-30 procedures. The carryover of allowance for loan losses related to acquired loans is prohibited as any credit losses in the loans are included in the determination of the fair value of the loans at the acquisition date. The allowance for loan losses on acquired loans reflects only those losses incurred after acquisition and represents the present value of cash flows expected at acquisition that is no longer expected to be collected. Acquired loans are marked to fair value on the date of acquisition. In conjunction with the quarterly evaluation of the adequacy of the allowance for loan losses, the Corporation performs an analysis on acquired loans to determine whether or not there has been subsequent deterioration in relation to those loans. If deterioration has occurred, the Corporation will include these loans in the calculation of the allowance for loan losses after the initial valuation, and provide accordingly. Upon acquisition, in accordance with Generally Accepted Accounting Principles, the Corporation has individually determined whether each acquired loan is within the scope of ASC 310-30. The Corporation’s senior lending management reviewed the accounting seller’s loan portfolio on a loan by loan basis to determine if any loans met the two-part definition of an impaired loan as defined by ASC 310-30: 1) Credit deterioration on the loan from its inception until the acquisition date, and 2) It is probable that not all of the contractual cash flows will be collected on the loan. Any acquired loans that were not individually in the scope of ASC 310-30 because they didn’t meet the criteria above were pooled into groups of similar loans based on various factors including borrower type, loan purpose, and collateral type. For these pools, we used certain loan information, including outstanding principal balance, estimated expected losses, weighted average maturity, weighted average margin, and weighted average interest rate along with estimated prepayment rates, expected lifetime losses, environment factors to estimate the expected cash flow for each loan pool. With regards to ASC 310-30 loans, for external disclosure purposes, the aggregate contractual cash flows less the aggregate expected cash flows will result in a credit related non-accretable yield amount. The aggregate expected cash flows less the acquisition date fair value will result in an accretable yield amount. The accretable yield reflects the contractual cash flows management expects to collect above the loan’s acquisition date fair value and will be recognized over the life of the loan on a level-yield basis as a component of interest income. Over the life of the acquired ASC 310-30 loan, we continue to estimate cash flows expected to be collected. Decreases in expected cash flows, other than from prepayments or rate adjustments, are recognized as impairments through a charge to the provision for credit losses resulting in an increase in the allowance for credit losses. Subsequent improvements in cash flows result in first, reversal of existing valuation allowances recognized subsequent to acquisition, if any, and next, an increase in the amount of accretable yield to be subsequently recognized on a prospective basis over the loan’s remaining life. Acquired ASC 310-30 loans that met the criteria for non-accrual of interest prior to acquisition are considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of expected cash flows on such loans. Accordingly, we do not consider acquired contractually delinquent loans to be non-accruing and continue to recognize interest income on these loans using the accretion model. For loans acquired without evidence of credit quality deterioration, ACNB prepared the interest rate loan fair value and credit fair value adjustments. Loans were grouped into homogeneous pools by characteristics such as loan type, term, collateral and rate. Market rates for similar loans were obtained from various internal and external data sources and reviewed by management for reasonableness. The average of these rates was used as the fair value interest rate a market participant would utilize. A present value approach was utilized to calculate the interest rate fair value discount of $731,000 . Additionally, for loans acquired without credit deterioration, a credit fair value adjustment was calculated using a two-part credit fair value analysis: 1) expected lifetime credit migration losses; and 2) estimated fair value adjustment for certain qualitative factors. The expected lifetime losses were calculated using historical losses observed at the Bank, NWSB and peer banks. ACNB also estimated an environmental factor to apply to each loan type. The environmental factor represents potential discount which may arise due to general credit and economic factors. A credit fair value discount of $4.5 million was determined. Both the interest rate and credit fair value adjustments relate to loans acquired with evidence of credit quality deterioration will be substantially recognized as interest income on a level yield amortization method over the expected life of the loans. The following table presents the classes of the loan portfolio summarized by the aggregate pass rating and the classified ratings of special mention, substandard, and doubtful within the Corporation’s internal risk rating system as of September 30, 2017 , and December 31, 2016 : In thousands Pass Special Mention Substandard Doubtful Total SEPTEMBER 30, 2017 Originated Loans Commercial and industrial $ 157,249 $ 3,348 $ 2,060 $ — $ 162,657 Commercial real estate 312,432 19,134 9,355 — 340,921 Commercial real estate construction 31,042 1,009 250 — 32,301 Residential mortgage 352,238 3,895 544 — 356,677 Home equity lines of credit 77,486 352 90 — 77,928 Consumer 14,413 — — — 14,413 Total Originated Loans 944,860 27,738 12,299 — 984,897 Acquired Loans Commercial and industrial 6,123 177 80 — 6,380 Commercial real estate 125,703 13,824 3,225 — 142,752 Commercial real estate construction 7,085 393 — — 7,478 Residential mortgage 58,927 2,932 3,196 — 65,055 Home equity lines of credit 26,726 88 371 — 27,185 Consumer 2,263 358 2 — 2,623 Total Acquired Loans 226,827 17,772 6,874 — 251,473 Total Loans Commercial and industrial 163,372 3,525 2,140 — 169,037 Commercial real estate 438,135 32,958 12,580 — 483,673 Commercial real estate construction 38,127 1,402 250 — 39,779 Residential mortgage 411,165 6,827 3,740 — 421,732 Home equity lines of credit 104,212 440 461 — 105,113 Consumer 16,676 358 2 — 17,036 Total Loans $ 1,171,687 $ 45,510 $ 19,173 $ — $ 1,236,370 DECEMBER 31, 2016 Commercial and industrial $ 134,088 $ 2,355 $ 3,901 $ — $ 140,344 Commercial real estate 291,762 17,376 9,842 — 318,980 Commercial real estate construction 13,606 1,202 463 — 15,271 Residential mortgage 344,048 3,617 874 — 348,539 Home equity lines of credit 69,190 756 126 — 70,072 Consumer 14,704 — — — 14,704 $ 867,398 $ 25,306 $ 15,206 $ — $ 907,910 The following table provides changes in accretable yield for all acquired loans accounted for under ASC 310-30. Loans accounted for under ASC 310-20 are not included in this table. In thousands Nine Months Ended September 30, 2017 Balance at beginning of period $ — Acquisitions of impaired loans 1,458 Reclassification from non-accretable differences — Accretion (111 ) Balance at end of period $ 1,347 Cash flows expected to be collected on acquired loans are estimated quarterly by incorporating several key assumptions similar to the initial estimate of fair value. These key assumptions include probability of default and the amount of actual prepayments after the acquisition date. Prepayments affect the estimated life of the loans and could change the amount of interest income, and possibly principal expected to be collected. In reforecasting future estimated cash flows, credit loss expectations are adjusted as necessary. Improved cash flow expectations for loans or pools are recorded first as a reversal of previously recorded impairment, if any, and then as an increase in prospective yield when all previously recorded impairment has been recaptured. Decreases in expected cash flows are recognized as impairment through a charge to the provision for loan losses and credit to the allowance for loan losses. The following table summarizes information relative to impaired loans by loan portfolio class as of September 30, 2017 , and December 31, 2016 : Impaired Loans with Allowance Impaired Loans with No Allowance In thousands Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance SEPTEMBER 30, 2017 Commercial and industrial $ 1,353 $ 1,353 $ 698 $ 390 $ 390 Commercial real estate 832 832 117 7,581 7,581 Residential mortgage 377 377 377 101 101 $ 2,562 $ 2,562 $ 1,192 $ 8,072 $ 8,072 DECEMBER 31, 2016 Commercial and industrial $ 948 $ 948 $ 599 $ 1,178 $ 1,178 Commercial real estate — — — 8,764 8,965 Commercial real estate construction — — — 300 300 Residential mortgage 376 376 333 379 379 $ 1,324 $ 1,324 $ 932 $ 10,621 $ 10,822 The following table summarizes information in regards to the average of impaired loans and related interest income by loan portfolio class for the three months ended September 30, 2017 and 2016 : Impaired Loans with Allowance Impaired Loans with No Allowance In thousands Average Recorded Investment Interest Income Average Recorded Investment Interest Income SEPTEMBER 30, 2017 Commercial and industrial $ 1,360 $ — $ 734 $ — Commercial real estate 832 — 7,626 80 Commercial real estate construction — — — — Residential mortgage 378 — 101 — $ 2,570 $ — $ 8,461 $ 80 SEPTEMBER 30, 2016 Commercial and industrial $ — $ — $ 1,361 $ 3 Commercial real estate — — 8,156 104 Commercial real estate construction — — 300 — Residential mortgage 374 — 414 4 $ 374 $ — $ 10,231 $ 111 The following table summarizes information in regards to the average of impaired loans and related interest income by loan portfolio class for the nine months ended September 30, 2017 and 2016 : Impaired Loans with Allowance Impaired Loans with No Allowance In thousands Average Recorded Investment Interest Income Average Recorded Investment Interest Income SEPTEMBER 30, 2017 Commercial and industrial $ 1,152 $ — $ 934 $ — Commercial real estate 416 — 8,155 293 Commercial real estate construction — — 75 25 Residential mortgage 377 — 238 15 $ 1,945 $ — $ 9,402 $ 333 SEPTEMBER 30, 2016 Commercial and industrial $ — $ — $ 1,400 $ 3 Commercial real estate — — 8,280 327 Commercial real estate construction — — 337 — Residential mortgage 187 — 435 13 $ 187 $ — $ 10,452 $ 343 No additional funds are committed to be advanced in connection with impaired

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Management uses its best judgment in estimating the fair value of the Corporation’s financial instruments; however, there are inherent weaknesses in any estimation technique. Therefore, for substantially all financial instruments, the fair value estimates herein are not necessarily indicative of the amounts the Corporation could have realized in a sales transaction on the dates indicated. The estimated fair value amounts have been measured as of their respective reporting dates and have not been reevaluated or updated for purposes of these consolidated financial statements subsequent to those respective dates. As such, the estimated fair values of these financial instruments subsequent to the respective reporting dates may be different than the amounts reported at each period end. Fair value measurement and disclosure guidance defines fair value as the price that would be received to sell the asset or transfer the liability in an orderly transaction (that is, not a forced liquidation or distressed sale) between market participants at the measurement date under current market conditions. Fair value measurement and disclosure guidance provides a list of factors that a reporting entity should evaluate to determine whether there has been a significant decrease in the volume and level of activity for the asset or liability in relation to normal market activity for the asset or liability. When the reporting entity concludes there has been a significant decrease in the volume and level of activity for the asset or liability, further analysis of the information from that market is needed and significant adjustments to the related prices may be necessary to estimate fair value in accordance with fair value measurement and disclosure guidance. This guidance further clarifies that when there has been a significant decrease in the volume and level of activity for the asset or liability, some transactions may not be orderly. In those situations, the entity must evaluate the weight of the evidence to determine whether the transaction is orderly. The guidance provides a list of circumstances that may indicate that a transaction is not orderly. A transaction price that is not associated with an orderly transaction is given little, if any, weight when estimating fair value. Fair value measurement and disclosure guidance establishes a fair value hierarchy that prioritizes the inputs to valuation methods used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are as follows: Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2: Quoted prices in markets that are not active, or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability. Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported with little or no market activity). An asset or liability’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. For assets measured at fair value, the fair value measurements by level within the fair value hierarchy, and the basis of measurement used, at September 30, 2017 , and December 31, 2016 , are as follows: September 30, 2017 In thousands Basis Total Level 1 Level 2 Level 3 U.S. Government and agencies $ 99,014 $ — $ 99,014 $ — Mortgage-backed securities, residential 37,351 — 37,351 — State and municipal 15,116 — 15,116 — Corporate bonds 5,112 — 5,112 — CRA mutual fund 1,042 1,042 — — Stock in other banks 757 757 — — Total securities available for sale Recurring $ 158,392 $ 1,799 $ 156,593 $ — Impaired loans Nonrecurring $ 5,462 $ — $ — $ 5,462 December 31, 2016 In thousands Basis Total Level 1 Level 2 Level 3 U.S. Government and agencies $ 79,579 $ — $ 79,579 $ — Mortgage-backed securities, residential 31,973 — 31,973 — State and municipal 24,660 — 24,660 — Corporate bonds 5,062 — 5,062 — CRA mutual fund 1,035 1,035 — — Stock in other banks 681 681 — — Total securities available for sale Recurring $ 142,990 $ 1,716 $ 141,274 $ — Impaired loans Nonrecurring $ 4,406 $ — $ — $ 4,406 The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis for which the Corporation has utilized Level 3 inputs to determine fair value: Quantitative Information about Level 3 Fair Value Measurements Dollars in thousands Fair Value Estimate Valuation Technique Unobservable Input Range Weighted Average September 30, 2017 Impaired loans $ 5,462 Appraisal of collateral (a) Appraisal adjustments (b) (10) - (50)% (34)% December 31, 2016 Impaired loans $ 4,406 Appraisal of collateral (a) Appraisal adjustments (b) (10) - (50)% (39)% (a) Fair value is generally determined through management’s estimate or independent third-party appraisals of the underlying collateral, which generally includes various Level 3 inputs which are not observable. (b) Appraisals may be adjusted downward by management for qualitative factors such as economic conditions and estimated liquidation expenses. The range of liquidation expenses and other appraisal adjustments are presented as a percentage of the appraisal. Higher downward adjustments are caused by negative changes to the collateral or conditions in the real estate market, actual offers or sales contracts received, and/or age of the appraisal. The following information should not be interpreted as an estimate of the fair value of the entire Corporation since a fair value calculation is only provided for a limited portion of the Corporation’s assets and liabilities. Due to a wide range of valuation techniques and the degree of subjectivity used in making the estimates, comparisons between the Corporation’s disclosures and those of other companies may not be meaningful. The following methods and assumptions were used to estimate the fair values of certain Corporation financial instruments at September 30, 2017 , and December 31, 2016 : Cash and Cash Equivalents (Carried at Cost) The carrying amounts reported in the consolidated statement of condition for cash and short-term instruments approximate those assets’ fair value. U.S. currency is Level 1 and cash equivalents are Level 2. Securities The fair values of securities available for sale (carried at fair value) and held to maturity (carried at amortized cost) are determined by obtaining quoted market prices on nationally recognized securities exchanges (Level 1), or matrix pricing (Level 2), which is a mathematical technique used widely in the industry to value debt securities without relying exclusively on quoted market prices for the specific security but rather by relying on the security’s relationship to other benchmark quoted prices. The Corporation uses an independent service provider to provide matrix pricing, and uses the valuation of another provider to compare for reasonableness. Loans Held for Sale (Carried at Lower of Cost or Fair Value) The fair values of mortgage loans held for sale are determined based on amounts to be received at settlement by establishing the respective buyer requirement or market interest rates. Loans (Carried at Cost) The fair values of non-impaired loans are estimated using discounted cash flow analyses, as well as using market rates at the balance sheet date that reflect the credit and interest rate risk inherent in the loans. Projected future cash flows are calculated based upon contractual maturity or call dates, projected repayments, and prepayments of principal. Generally, for variable rate loans that reprice frequently and with no significant change in credit risk, fair values are based on carrying values. Impaired Loans (Generally Carried at Fair Value) Loans for which the Corporation has measured impairment are generally based on the fair value of the loan’s collateral. Fair value is generally determined based upon independent third-party appraisals of the properties, or discounted cash flows based upon the expected proceeds. These assets are included as Level 3 fair values, based upon the lowest level of input that is significant to the fair value measurements. The fair value consists of the loan balances less the valuation allowance and/or charge-offs. Foreclosed Assets Held for Resale The fair value of real estate acquired through foreclosure is based on independent third-party appraisals of the properties. These assets are included as Level 3 fair values, based upon appraisals that consider the sales prices of similar properties in the proximate vicinity. It is the policy of the Corporation to have the initial market value of a foreclosed asset held for resale determined by an independent third-party valuation. If the Corporation already has a valid appraisal on file for the property and that appraisal has been completed within the previous 12 months, another appraisal shall not be required when the Corporation acquires ownership of that real estate. Further, the Corporation shall update the market value of each foreclosed asset with an independent third-party valuation at least every 18 months , or more frequently if management believes that there is an indication that the fair value has declined. These valuations may be adjusted downward to account for specialized use of the property, change in the condition of the real estate, change in local market and economic conditions, and other specific factors involving the collateral. Restricted Investment in Bank Stock (Carried at Cost) The carrying amount of required and restricted investment in correspondent bank stock approximates fair value, and considers the limited marketability of such securities. Accrued Interest Receivable and Payable (Carried at Cost) The carrying amounts of accrued interest receivable and accrued interest payable approximate their fair value. Deposits (Carried at Cost) The fair values disclosed for demand deposits (e.g., interest and non-interest checking, savings, and money market accounts) are, by definition, equal to the amount payable on demand at the reporting date (e.g., their carrying amounts). Fair values for fixed-rate certificates of deposit are estimated using a discounted cash flow calculation that applies market interest rates currently being offered in the market on certificates to a schedule of aggregated expected monthly maturities on time deposits. Short-Term Borrowings (Carried at Cost) The carrying amounts of short-term borrowings approximate their fair values. Long-Term Borrowings (Carried at Cost) The fair values of long-term borrowings are estimated using discounted cash flow analysis, based on quoted prices for new borrowings with similar credit risk characteristics, terms, and remaining maturity. The prices obtained from this active market represent a market value that is deemed to represent the transfer price if the liability were assumed by a third party. The fair value of the trust preferred subordinated debt, included in long-term borrowings, was determined based upon an estimated fair value from an independent brokerage firm. Off-Balance Sheet Credit-Related Instruments The fair values for the Corporation’s off-balance sheet financial instruments (specifically, lending commitments and letters of credit) are based on fees currently charged in the market to enter into similar agreements, taking into account the remaining terms of the agreements and the counterparties’ credit standing. The following presents the carrying amount, fair value, and placement in the fair value hierarchy of the Corporation’s financial instruments as of September 30, 2017 , and December 31, 2016 : September 30, 2017 In thousands Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and due from banks $ 17,882 $ 17,882 $ 8,131 $ 9,751 $ — Interest-bearing deposits in banks 31,609 31,609 31,609 — — Investment securities available for sale 158,392 158,392 1,799 156,593 — Investment securities held to maturity 47,369 47,373 — 47,373 — Loans held for sale 1,873 1,873 — 1,873 — Loans, less allowance for loan losses 1,222,265 1,205,807 — — 1,205,807 Accrued interest receivable 3,795 3,795 — 3,795 — Restricted investment in bank stocks 4,821 4,821 — 4,821 — Financial liabilities: Deposits 1,311,884 1,307,677 — 1,307,677 — Short-term borrowings 33,806 33,806 — 33,806 — Long-term borrowings 96,850 97,129 — 97,129 — Accrued interest payable 1,072 1,072 — 1,072 — Off-balance sheet financial instruments — — — — — December 31, 2016 In thousands Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and due from banks $ 13,796 $ 13,796 $ 6,921 $ 6,875 $ — Interest-bearing deposits in banks 5,135 5,135 5,135 — — Investment securities available for sale 142,990 142,990 1,716 141,274 — Investment securities held to maturity 55,568 55,425 — 55,425 — Loans held for sale 1,770 1,770 — 1,770 — Loans, less allowance for loan losses 893,176 888,169 — — 888,169 Accrued interest receivable 3,158 3,158 — 3,158 — Restricted investment in bank stocks 4,349 4,349 — 4,349 — Financial liabilities: Deposits 967,621 967,236 — 967,236 — Short-term borrowings 34,590 34,590 — 34,590 — Long-term borrowings 74,250 75,029 — 75,029 — Accrued interest payable 837 837 — 837 — Off-balance sheet financial instruments — — — — —

Securities Sold Under Agreement

Securities Sold Under Agreements to Repurchase (Repurchase Agreements)	9 Months Ended
	Sep. 30, 2017
Disclosure of Repurchase Agreements [Abstract]
Securities Sold Under Agreements to Repurchase (Repurchase Agreements)	Securities Sold Under Agreements to Repurchase (Repurchase Agreements) The Corporation enters into agreements under which it sells securities subject to an obligation to repurchase the same or similar securities. Under these arrangements, the Corporation may transfer legal control over the assets but still retain effective control through an agreement that both entitles and obligates the Corporation to repurchase the assets. As a result, these repurchase agreements are accounted for as collateralized financing agreements (i.e., secured borrowings) and not as a sale and subsequent repurchase of securities. The obligation to repurchase the securities is reflected as a liability in the Corporation’s consolidated statements of condition, while the securities underlying the repurchase agreements remain in the respective investment securities asset accounts. In other words, there is no offsetting or netting of the investment securities assets with the repurchase agreement liabilities. In addition, as the Corporation does not enter into reverse repurchase agreements, there is no such offsetting to be done with the repurchase agreements. The right of setoff for a repurchase agreement resembles a secured borrowing, whereby the collateral would be used to settle the fair value of the repurchase agreement should the Corporation be in default (e.g., fails to make an interest payment to the counterparty). For private institution repurchase agreements, if the private institution counterparty were to default (e.g., declare bankruptcy), the Corporation could cancel the repurchase agreement (i.e., cease payment of principal and interest), and attempt collection on the amount of collateral value in excess of the repurchase agreement fair value. The collateral is held by a third-party financial institution in the counterparty’s custodial account. The counterparty has the right to sell or repledge the investment securities. For government entity repurchase agreements, the collateral is held by the Corporation in a segregated custodial account under a tri-party agreement. The following table presents the short-term borrowings subject to an enforceable master netting arrangement or repurchase agreement as of September 30, 2017 , and December 31, 2016 : Gross Amounts Not Offset in the Statements of Condition In thousands Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statements of Condition Net Amounts of Liabilities Presented in the Statements of Condition Financial Instruments Cash Collateral Pledged Net Amount September 30, 2017 Repurchase agreements Commercial customers and government entities (a) $ 33,806 $ — $ 33,806 $ (33,806 ) $ — $ — December 31, 2016 Repurchase agreements Commercial customers and government entities (a) $ 34,590 $ — $ 34,590 $ (34,590 ) $ — $ — (a) As of September 30, 2017 , and December 31, 2016 , the fair value of securities pledged in connection with repurchase agreements was $41,149,000 and $41,406,000 , respectively. The following table presents the remaining contractual maturity of the master netting arrangement or repurchase agreements as of September 30, 2017 : Remaining Contractual Maturity of the Agreements In thousands Overnight and Continuous Up to 30 Days 30 - 90 Days Greater than 90 Days Total Repurchase agreements and repurchase-to-maturity transactions U.S. Treasury and agency securities $ 33,806 $ — $ — $ — $ 33,806 Total $ 33,806 $ — $ — $ — $ 33,806

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Borrowings	Borrowings The Corporation had long-term debt outstanding as follows: In thousands September 30, 2017 December 31, 2016 FHLB Advances $ 87,250 $ 74,250 Loan Payable to local bank 4,600 — Trust preferred subordinated debt 5,000 — $ 96,850 $ 74,250 The FHLB advances are collateralized by the assets defined in security agreement and FHLB capital stock. FHLB advances have maturity dates from 2017 to 2021 with a weighted average rate of 1.80% . The loan payable to a local bank has a one -year draw period in which monthly interest-only payments are due on the outstanding principal amount. Commencing June 2018, terms include a fixed rate of 4.5% for the first five years and a variable rate of interest with Prime Rate thereafter to final maturity in June 2028. The borrower may prepay the principal balance of this note at any time without penalty. The trust preferred subordinated debt is comprised of debt securities issued by NW Bancorp in June 2005 and assumed by ACNB Corporation through the acquisition. NW Bancorp issued $5,000,000 of 6.39% fixed rate capital securities to institutional investors in a private pooled transaction. The proceeds were transferred to NW Bancorp as trust preferred subordinated debt under the same terms and conditions. The Corporation then contributed the full amount to the Bank in the form of Tier 1 capital. The Corporation has, through various contractual arrangements, fully and unconditionally guaranteed all of the trust obligations with respect to the capital securities.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the excess of the cost of an acquisition over the fair value of the net assets acquired. Other intangible assets represent purchased assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights. Intangible assets that have finite lives, such as core deposit intangibles, customer relationship intangibles and renewal lists, are amortized over their estimated useful lives and subject to periodic impairment testing. Core deposit intangibles are primarily amortized over ten years using accelerated methods. Customer renewal lists are amortized over their estimated useful lives which range from eight to thirteen years. This acquisition of NW Bancorp resulted in goodwill of approximately $13.3 million and generated $2.4 million in core deposit intangibles. Combining goodwill resulting from this transaction with existing goodwill from the 2005 RIG purchase of $6,308,000 , total goodwill included in the Corporation’s consolidated statement of condition is $19,580,000 . Goodwill is not deductible for federal income tax purposes. Goodwill, which has an indefinite useful life, is evaluated for impairment annually and is evaluated for impairment more frequently if events and circumstances indicate that the asset might be impaired. The carrying value and accumulated amortization of the intangible assets (RIG customer lists and NW Bancorp core deposit intangibles) are as follows: In thousands Gross carrying amount Accumulated amortization RIG amortized intangible assets $ 6,667 $ 6,223 NW Bancorp core deposit intangibles 2,418 110 The RIG intangible assets are being amortized over 10 years on a straight line basis. The NW Bancorp core deposit intangible is being amortized using a sum of the year’s method over a 10 -year period. Goodwill is subject to impairment testing at the reporting unit level, which must be conducted at least annually. We perform impairment testing during the fourth quarter of each year, or more frequently if impairment indicators exist. We also continue to monitor other intangibles for impairment and to evaluate carrying amounts, as necessary.

New Accounting Pronouncements

New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements ASU 2014-09, 2015-14, 2016-08, 2016-12, 2016-20, and 2017-10 In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). The amendments in this Update establish a comprehensive revenue recognition standard for virtually all industries under U.S. GAAP, including those that previously followed industry-specific guidance such as the real estate, construction and software industries. The revenue standard’s core principle is built on the contract between a vendor and a customer for the provision of goods and services. It attempts to depict the exchange of rights and obligations between the parties in the pattern of revenue recognition based on the consideration to which the vendor is entitled. To accomplish this objective, the standard requires five basic steps: (i) identify the contract with the customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The amendments in this Update were originally effective for public entities for annual periods beginning after December 15, 2016, including interim periods therein. Three basic transition methods are available — full retrospective, retrospective with certain practical expedients, and a cumulative effect approach. Under the third alternative, an entity would apply the new revenue standard only to contracts that are incomplete under legacy U.S. GAAP at the date of initial application and recognize the cumulative effect of the new standard as an adjustment to the opening balance of retained earnings. That is, prior years would not be restated and additional disclosures would be required to enable users of the financial statements to understand the impact of adopting the new standard in the current year compared to prior years that are presented under legacy U.S. GAAP. Early adoption is prohibited under U.S. GAAP. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606) . ASU 2015-14 defers the effective date of the new revenue recognition standard by one year. As such, it now takes effect for public entities in fiscal years beginning after December 15, 2017. All other entities have an additional year. However, early adoption is permitted for any entity that chooses to adopt the new standard as of the original effective date. Public business entities will adopt the standard for annual reporting periods beginning after December 15, 2017, including interim periods within that year. Early adoption is permitted only as of annual reporting periods beginning after December 15, 2016, including interim periods within that year. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) . ASU 2016-08 updates the new revenue standard by clarifying the principal versus agent implementation guidance, but does not change the core principle of the new standard. The updates to the principal versus agent guidance: • require an entity to determine whether it is a principal or an agent for each distinct good or service (or a distinct bundle of goods or services) to be provided to the customer; • illustrate how an entity that is a principal might apply the control principle to goods, services, or rights to services, when another party is involved in providing goods or services to a customer; • clarify that the purpose of certain specific control indicators is to support or assist in the assessment of whether an entity controls a good or service before it is transferred to the customer, provide more specific guidance on how the indicators should be considered, and clarify that their relevance will vary depending on the facts and circumstances; and • revise existing examples and add two new ones to more clearly depict how the guidance should be applied. In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients. The amendments do not alter the core principle of the new revenue standard, but make certain targeted changes to clarify the following: • Assessing collectibility - The amendments add a “substantially all” threshold to the collectibility criterion, and also clarify that the objective of the collectibility assessment is to determine whether the contract is valid and represents a substantive transaction based on whether a customer has the ability and intent to pay for the goods or services that will be transferred to the customer, as opposed to all of the goods or services promised in the contract. The ASU also clarifies how an entity may recognize as revenue consideration received in circumstances where a contract does not meet the criteria required at inception to apply the recognition guidance within the revenue standard. • Presenting sales taxes and other similar taxes collected from customers - The amendments provide an accounting policy election whereby an entity may exclude from the measurement of transaction price all taxes assessed by a taxing authority related to the specific transaction and which are collected from the customer. Such amounts would be presented “net” under this option. • Noncash consideration - The amendments clarify that the fair value of noncash consideration is measured at contract inception, and specify how to account for subsequent changes in the fair value of noncash consideration. • Contract modifications at transition - The amendments provide a new practical expedient whereby an entity electing either the full or modified retrospective method of transition is permitted to reflect the aggregate effect of all prior period modifications (using hindsight) when identifying satisfied and unsatisfied performance obligations, determining the transaction price, and allocating the transaction price to satisfied and unsatisfied obligations. • Completed contracts at transition - The amendments include certain practical expedients in transition related to completed contracts. The amendments also clarify the definition of a completed contract. • Disclosing the accounting change in the period of adoption - ASU 2016-12 provides an exception to the requirement in Topic 250 to disclose the effect on the current period of retrospectively adopting a new accounting standard. In December 2016, the FASB issued ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers , which amends the new revenue standard. The amendments do not alter the core principle of the standard, but clarify certain narrow aspects of the standard including contract cost accounting, disclosures, illustrative examples, and other matters. The effective date and transition requirements for ASU 2016-20 are the same as the effective date and transition requirements of Topic 606. In May 2017, the FASB issued ASU 2017-10, Determining the Customer of the Operation Services , which amends Topic 853 to clarify that when applying Topic 606, an operating entity in a service concession arrangement should consider the grantor to be its customer for the services it provides in all cases. This includes the construction of the infrastructure, if any, as well as operating services. The FASB ultimately concluded the operating entity is acting as the grantor’s service provider to operate and maintain the infrastructure, which is controlled by the grantor, and the only parties to the executed service concession arrangement are the grantor and the operating entity. The effective date and transition requirements for ASU 2017-10 are the same as the effective date and transition requirements for Topic 606. The Corporation’s revenue is comprised of net interest income on financial assets and financial liabilities, which is explicitly excluded from the scope of ASU 2014-09, and non-interest income. With respect to non-interest income, the Corporation has identified revenue streams within the scope of the guidance, and has performed an evaluation of the underlying revenue contracts. Alternative methods are available for cash receipts of contingent commissions from the insurance agency segment. The method chosen will have a bearing on when this revenue source is recognized and can vary from period to period. ASU 2016-01 In January 2016, the FASB issued ASU 2016-01, Financial Instruments—Overall (Topic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 amends the guidance on the classification and measurement of financial instruments. Some of the amendments in ASU 2016-01 include the following among others: (i) requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (iii) requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; and, (iv) requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value. For public business entities, the amendments of ASU 2016-01 are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Corporation is currently evaluating the impact this ASU will have on its consolidated financial condition or results of operations. ASU 2016-02 In February 2016, the FASB issued ASU 2016-02, Leases . From the lessee’s perspective, the new standard establishes a right-of-use (ROU) model that requires a lessee to record an ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement for a lessee. From the lessor’s perspective, the new standard requires a lessor to classify leases as either sales-type, finance or operating. A lease will be treated as a sale if it transfers all of the risks and rewards, as well as control of the underlying asset, to the lessee. If risks and rewards are conveyed without the transfer of control, the lease is treated as a financing lease. If the lessor doesn’t convey risks and rewards or control, an operating lease results. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach is required for lessees for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. A modified retrospective transition approach is required for lessors for sales-type, direct financing, and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. While the Corporation is currently evaluating the timing and impact of adopting ASU 2016-02, the ultimate impact of adopting ASU 2016-02 will depend on the Corporation’s lease portfolio as of the adoption date. ASU 2016-09 In March 2016, the FASB issued ASU 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting . ASU 2016-09 introduces targeted amendments intended to simplify the accounting for stock compensation. Specifically, the ASU requires all excess tax benefits and tax deficiencies (including tax benefits of dividends on share-based payment awards) to be recognized as income tax expense or benefit in the income statement. The tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. An entity also should recognize excess tax benefits, and assess the need for a valuation allowance, regardless of whether the benefit reduces taxes payable in the current period. That is, off balance sheet accounting for net operating losses stemming from excess tax benefits would no longer be required and instead such net operating losses would be recognized when they arise. Existing net operating losses that are currently tracked off balance sheet would be recognized, net of a valuation allowance if required, through an adjustment to opening retained earnings in the period of adoption. Entities will no longer need to maintain and track an “APIC pool.” The ASU also requires excess tax benefits to be classified along with other income tax cash flows as an operating activity in the statement of cash flows. In addition, the ASU elevates the statutory tax withholding threshold to qualify for equity classification up to the maximum statutory tax rates in the applicable jurisdiction(s). The ASU also clarifies that cash paid by an employer when directly withholding shares for tax withholding purposes should be classified as a financing activity. The ASU provides an optional accounting policy election (with limited exceptions), to be applied on an entity-wide basis, to either estimate the number of awards that are expected to vest (consistent with existing U.S. GAAP) or account for forfeitures when they occur. The amendments are effective for public business entities for annual periods beginning after December 15, 2016, and interim periods within those annual periods. The Corporation has evaluated the provision of ASU 2016-09 to determine the potential impact of the new standard and has determined that it does not have an impact on its consolidated financial condition or results of operations. ASU 2016-13 In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires credit losses on most financial assets measured at amortized cost and certain other instruments to be measured using an expected credit loss model (referred to as the current expected credit loss (CECL) model). Under this model, entities will estimate credit losses over the entire contractual term of the instrument (considering estimated prepayments, but not expected extensions or modifications unless reasonable expectation of a troubled debt restructuring exists) from the date of initial recognition of that instrument. The ASU also replaces the current accounting model for purchased credit impaired loans and debt securities. The allowance for credit losses for purchased financial assets with a more-than insignificant amount of credit deterioration since origination (“PCD assets”), should be determined in a similar manner to other financial assets measured on an amortized cost basis. However, upon initial recognition, the allowance for credit losses is added to the purchase price (“gross up approach”) to determine the initial amortized cost basis. The subsequent accounting for PCD financial assets is the same expected loss model described above. Further, the ASU made certain targeted amendments to the existing impairment model for available-for-sale (AFS) debt securities. For an AFS debt security for which there is neither the intent nor a more-likely-than-not requirement to sell, an entity will record credit losses as an allowance rather than a write-down of the amortized cost basis. Certain incremental disclosures are required. The new standard is effective for fiscal years beginning after December 15, 2019, including interim periods within the fiscal year. For public business entities that are SEC filers, the amendments are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. The Corporation is currently evaluating the impact this ASU will have on its consolidated financial condition or results of operations. ASU 2017-08 In March 2017, the FASB issued ASU 2017-08, Premium Amortization on Purchased Callable Debt Securities . ASU 2017-08 shortens the amortization period for premiums on purchased callable debt securities to the earliest call date (i.e., yield-to-earliest call amortization), rather than amortizing over the full contractual term. The ASU does not change the accounting for securities held at a discount. The amendments apply to callable debt securities with explicit, noncontingent call features that are callable at fixed prices and on preset dates. If a security may be prepaid based upon prepayments of the underlying loans, not because the issuer exercised a date specific call option, it is excluded from the scope of the new standard. However, for instruments with contingent call features, once the contingency is resolved and the security is callable at a fixed price and preset date, the security is within the scope of the amendments. Further, the amendments apply to all premiums on callable debt securities, regardless of how they were generated. The amendments require companies to reset the effective yield using the payment terms of the debt security if the call option is not exercised on the earliest call date. If the security has additional future call dates, any excess of the amortized cost basis over the amount repayable by the issuer at the next call date should be amortized to the next call date. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those years. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. The Corporation has evaluated the provision of ASU 2017-08 to determine the potential impact of the new standard and has determined that it is not expected to have a significant impact on its consolidated financial condition or results of operations, as the Corporation holds one security that this ASU would impact. ASU 2017-07 In March 2017, the FASB issued ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. ASU 2017-07 requires that an employer disaggregate the service cost component from the other components of net benefit cost, as follows: • Service cost must be presented in the same line item(s) as other employee compensation costs. These costs are generally included within income from continuing operations, but in some cases may be eligible for capitalization, if certain criteria are met. • All other components of net benefit cost must be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. These generally include interest cost, actual return on plan assets, amortization of prior service cost included in accumulated other comprehensive income, and gains or losses from changes in the value of the projected benefit obligation or plan assets. If a separate line item is used to present the other components of net benefit cost, it must be appropriately described. If a separate line item is not used, an entity must disclose the line item(s) in the income statement that includes the other components of net benefit cost. The ASU clarifies that these costs are not eligible for capitalization. The amendments are effective for public business entities for fiscal years beginning after December 15, 2017, including interim periods within those years. Early adoption is permitted as of the beginning of an annual period. The Corporation is currently evaluating if this ASU will have an impact on its consolidated financial condition or results of operations. ASU 2017-04 In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment. ASU 2017-04 eliminates Step 2 of the goodwill impairment test. As such, an entity will perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize a goodwill impairment charge for the amount by which the reporting unit’s carrying amount exceeds its fair value. If fair value exceeds the carrying amount, no impairment should be recorded. Any loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Impairment losses on goodwill cannot be reversed once recognized. An entity may still perform the optional qualitative assessment for a reporting unit to determine if it is more likely than not that goodwill is impaired. However, the ASU eliminates the requirement to perform a qualitative assessment for any reporting unit with a zero or negative carrying amount. Therefore, the same one-step impairment assessment will apply to all reporting units. However, for a reporting unit with a zero or negative carrying amount, the ASU adds a requirement to disclose the amount of goodwill allocated to it and the reportable segment in which it is included. For public business entities that are SEC filers, the amendments are effective with their annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Corporation has evaluated the provision of ASU 2017-04 to determine the potential impact of the new standard and has determined that it is not expected to have an impact on its consolidated financial condition or results of operations based on the current circumstances. ASU 2017-13 In September 2017, the FASB issued ASU 2017-13, Revenue Recognition (Topic 605), Revenue from Contracts with Customers (Topic 606), Leases (Topic 840), and Leases (Topic 842). ASU 2017-13 adds SEC paragraphs pursuant to an SEC Staff Announcement made at the July 20, 2017 Emerging Issues Task Force (EITF) meeting. The SEC staff announced that it will not object if an entity that qualifies as a public business entity solely because its financial statements or financial information is included in another entity’s filing with the SEC adopts ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and ASU 2016-02, Leases (Topic 842) using the effective dates applicable to private entities. The amendments represent guidance related to the effective dates of the standards noted above, therefore, the amendments themselves do not have an effective date.

New Accounting Pronouncements (

New Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements ASU 2014-09, 2015-14, 2016-08, 2016-12, 2016-20, and 2017-10 In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). The amendments in this Update establish a comprehensive revenue recognition standard for virtually all industries under U.S. GAAP, including those that previously followed industry-specific guidance such as the real estate, construction and software industries. The revenue standard’s core principle is built on the contract between a vendor and a customer for the provision of goods and services. It attempts to depict the exchange of rights and obligations between the parties in the pattern of revenue recognition based on the consideration to which the vendor is entitled. To accomplish this objective, the standard requires five basic steps: (i) identify the contract with the customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The amendments in this Update were originally effective for public entities for annual periods beginning after December 15, 2016, including interim periods therein. Three basic transition methods are available — full retrospective, retrospective with certain practical expedients, and a cumulative effect approach. Under the third alternative, an entity would apply the new revenue standard only to contracts that are incomplete under legacy U.S. GAAP at the date of initial application and recognize the cumulative effect of the new standard as an adjustment to the opening balance of retained earnings. That is, prior years would not be restated and additional disclosures would be required to enable users of the financial statements to understand the impact of adopting the new standard in the current year compared to prior years that are presented under legacy U.S. GAAP. Early adoption is prohibited under U.S. GAAP. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606) . ASU 2015-14 defers the effective date of the new revenue recognition standard by one year. As such, it now takes effect for public entities in fiscal years beginning after December 15, 2017. All other entities have an additional year. However, early adoption is permitted for any entity that chooses to adopt the new standard as of the original effective date. Public business entities will adopt the standard for annual reporting periods beginning after December 15, 2017, including interim periods within that year. Early adoption is permitted only as of annual reporting periods beginning after December 15, 2016, including interim periods within that year. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) . ASU 2016-08 updates the new revenue standard by clarifying the principal versus agent implementation guidance, but does not change the core principle of the new standard. The updates to the principal versus agent guidance: • require an entity to determine whether it is a principal or an agent for each distinct good or service (or a distinct bundle of goods or services) to be provided to the customer; • illustrate how an entity that is a principal might apply the control principle to goods, services, or rights to services, when another party is involved in providing goods or services to a customer; • clarify that the purpose of certain specific control indicators is to support or assist in the assessment of whether an entity controls a good or service before it is transferred to the customer, provide more specific guidance on how the indicators should be considered, and clarify that their relevance will vary depending on the facts and circumstances; and • revise existing examples and add two new ones to more clearly depict how the guidance should be applied. In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients. The amendments do not alter the core principle of the new revenue standard, but make certain targeted changes to clarify the following: • Assessing collectibility - The amendments add a “substantially all” threshold to the collectibility criterion, and also clarify that the objective of the collectibility assessment is to determine whether the contract is valid and represents a substantive transaction based on whether a customer has the ability and intent to pay for the goods or services that will be transferred to the customer, as opposed to all of the goods or services promised in the contract. The ASU also clarifies how an entity may recognize as revenue consideration received in circumstances where a contract does not meet the criteria required at inception to apply the recognition guidance within the revenue standard. • Presenting sales taxes and other similar taxes collected from customers - The amendments provide an accounting policy election whereby an entity may exclude from the measurement of transaction price all taxes assessed by a taxing authority related to the specific transaction and which are collected from the customer. Such amounts would be presented “net” under this option. • Noncash consideration - The amendments clarify that the fair value of noncash consideration is measured at contract inception, and specify how to account for subsequent changes in the fair value of noncash consideration. • Contract modifications at transition - The amendments provide a new practical expedient whereby an entity electing either the full or modified retrospective method of transition is permitted to reflect the aggregate effect of all prior period modifications (using hindsight) when identifying satisfied and unsatisfied performance obligations, determining the transaction price, and allocating the transaction price to satisfied and unsatisfied obligations. • Completed contracts at transition - The amendments include certain practical expedients in transition related to completed contracts. The amendments also clarify the definition of a completed contract. • Disclosing the accounting change in the period of adoption - ASU 2016-12 provides an exception to the requirement in Topic 250 to disclose the effect on the current period of retrospectively adopting a new accounting standard. In December 2016, the FASB issued ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers , which amends the new revenue standard. The amendments do not alter the core principle of the standard, but clarify certain narrow aspects of the standard including contract cost accounting, disclosures, illustrative examples, and other matters. The effective date and transition requirements for ASU 2016-20 are the same as the effective date and transition requirements of Topic 606. In May 2017, the FASB issued ASU 2017-10, Determining the Customer of the Operation Services , which amends Topic 853 to clarify that when applying Topic 606, an operating entity in a service concession arrangement should consider the grantor to be its customer for the services it provides in all cases. This includes the construction of the infrastructure, if any, as well as operating services. The FASB ultimately concluded the operating entity is acting as the grantor’s service provider to operate and maintain the infrastructure, which is controlled by the grantor, and the only parties to the executed service concession arrangement are the grantor and the operating entity. The effective date and transition requirements for ASU 2017-10 are the same as the effective date and transition requirements for Topic 606. The Corporation’s revenue is comprised of net interest income on financial assets and financial liabilities, which is explicitly excluded from the scope of ASU 2014-09, and non-interest income. With respect to non-interest income, the Corporation has identified revenue streams within the scope of the guidance, and has performed an evaluation of the underlying revenue contracts. Alternative methods are available for cash receipts of contingent commissions from the insurance agency segment. The method chosen will have a bearing on when this revenue source is recognized and can vary from period to period. ASU 2016-01 In January 2016, the FASB issued ASU 2016-01, Financial Instruments—Overall (Topic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 amends the guidance on the classification and measurement of financial instruments. Some of the amendments in ASU 2016-01 include the following among others: (i) requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (iii) requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; and, (iv) requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value. For public business entities, the amendments of ASU 2016-01 are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Corporation is currently evaluating the impact this ASU will have on its consolidated financial condition or results of operations. ASU 2016-02 In February 2016, the FASB issued ASU 2016-02, Leases . From the lessee’s perspective, the new standard establishes a right-of-use (ROU) model that requires a lessee to record an ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement for a lessee. From the lessor’s perspective, the new standard requires a lessor to classify leases as either sales-type, finance or operating. A lease will be treated as a sale if it transfers all of the risks and rewards, as well as control of the underlying asset, to the lessee. If risks and rewards are conveyed without the transfer of control, the lease is treated as a financing lease. If the lessor doesn’t convey risks and rewards or control, an operating lease results. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach is required for lessees for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. A modified retrospective transition approach is required for lessors for sales-type, direct financing, and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. While the Corporation is currently evaluating the timing and impact of adopting ASU 2016-02, the ultimate impact of adopting ASU 2016-02 will depend on the Corporation’s lease portfolio as of the adoption date. ASU 2016-09 In March 2016, the FASB issued ASU 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting . ASU 2016-09 introduces targeted amendments intended to simplify the accounting for stock compensation. Specifically, the ASU requires all excess tax benefits and tax deficiencies (including tax benefits of dividends on share-based payment awards) to be recognized as income tax expense or benefit in the income statement. The tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. An entity also should recognize excess tax benefits, and assess the need for a valuation allowance, regardless of whether the benefit reduces taxes payable in the current period. That is, off balance sheet accounting for net operating losses stemming from excess tax benefits would no longer be required and instead such net operating losses would be recognized when they arise. Existing net operating losses that are currently tracked off balance sheet would be recognized, net of a valuation allowance if required, through an adjustment to opening retained earnings in the period of adoption. Entities will no longer need to maintain and track an “APIC pool.” The ASU also requires excess tax benefits to be classified along with other income tax cash flows as an operating activity in the statement of cash flows. In addition, the ASU elevates the statutory tax withholding threshold to qualify for equity classification up to the maximum statutory tax rates in the applicable jurisdiction(s). The ASU also clarifies that cash paid by an employer when directly withholding shares for tax withholding purposes should be classified as a financing activity. The ASU provides an optional accounting policy election (with limited exceptions), to be applied on an entity-wide basis, to either estimate the number of awards that are expected to vest (consistent with existing U.S. GAAP) or account for forfeitures when they occur. The amendments are effective for public business entities for annual periods beginning after December 15, 2016, and interim periods within those annual periods. The Corporation has evaluated the provision of ASU 2016-09 to determine the potential impact of the new standard and has determined that it does not have an impact on its consolidated financial condition or results of operations. ASU 2016-13 In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires credit losses on most financial assets measured at amortized cost and certain other instruments to be measured using an expected credit loss model (referred to as the current expected credit loss (CECL) model). Under this model, entities will estimate credit losses over the entire contractual term of the instrument (considering estimated prepayments, but not expected extensions or modifications unless reasonable expectation of a troubled debt restructuring exists) from the date of initial recognition of that instrument. The ASU also replaces the current accounting model for purchased credit impaired loans and debt securities. The allowance for credit losses for purchased financial assets with a more-than insignificant amount of credit deterioration since origination (“PCD assets”), should be determined in a similar manner to other financial assets measured on an amortized cost basis. However, upon initial recognition, the allowance for credit losses is added to the purchase price (“gross up approach”) to determine the initial amortized cost basis. The subsequent accounting for PCD financial assets is the same expected loss model described above. Further, the ASU made certain targeted amendments to the existing impairment model for available-for-sale (AFS) debt securities. For an AFS debt security for which there is neither the intent nor a more-likely-than-not requirement to sell, an entity will record credit losses as an allowance rather than a write-down of the amortized cost basis. Certain incremental disclosures are required. The new standard is effective for fiscal years beginning after December 15, 2019, including interim periods within the fiscal year. For public business entities that are SEC filers, the amendments are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. The Corporation is currently evaluating the impact this ASU will have on its consolidated financial condition or results of operations. ASU 2017-08 In March 2017, the FASB issued ASU 2017-08, Premium Amortization on Purchased Callable Debt Securities . ASU 2017-08 shortens the amortization period for premiums on purchased callable debt securities to the earliest call date (i.e., yield-to-earliest call amortization), rather than amortizing over the full contractual term. The ASU does not change the accounting for securities held at a discount. The amendments apply to callable debt securities with explicit, noncontingent call features that are callable at fixed prices and on preset dates. If a security may be prepaid based upon prepayments of the underlying loans, not because the issuer exercised a date specific call option, it is excluded from the scope of the new standard. However, for instruments with contingent call features, once the contingency is resolved and the security is callable at a fixed price and preset date, the security is within the scope of the amendments. Further, the amendments apply to all premiums on callable debt securities, regardless of how they were generated. The amendments require companies to reset the effective yield using the payment terms of the debt security if the call option is not exercised on the earliest call date. If the security has additional future call dates, any excess of the amortized cost basis over the amount repayable by the issuer at the next call date should be amortized to the next call date. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those years. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. The Corporation has evaluated the provision of ASU 2017-08 to determine the potential impact of the new standard and has determined that it is not expected to have a significant impact on its consolidated financial condition or results of operations, as the Corporation holds one security that this ASU would impact. ASU 2017-07 In March 2017, the FASB issued ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. ASU 2017-07 requires that an employer disaggregate the service cost component from the other components of net benefit cost, as follows: • Service cost must be presented in the same line item(s) as other employee compensation costs. These costs are generally included within income from continuing operations, but in some cases may be eligible for capitalization, if certain criteria are met. • All other components of net benefit cost must be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. These generally include interest cost, actual return on plan assets, amortization of prior service cost included in accumulated other comprehensive income, and gains or losses from changes in the value of the projected benefit obligation or plan assets. If a separate line item is used to present the other components of net benefit cost, it must be appropriately described. If a separate line item is not used, an entity must disclose the line item(s) in the income statement that includes the other components of net benefit cost. The ASU clarifies that these costs are not eligible for capitalization. The amendments are effective for public business entities for fiscal years beginning after December 15, 2017, including interim periods within those years. Early adoption is permitted as of the beginning of an annual period. The Corporation is currently evaluating if this ASU will have an impact on its consolidated financial condition or results of operations. ASU 2017-04 In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment. ASU 2017-04 eliminates Step 2 of the goodwill impairment test. As such, an entity will perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize a goodwill impairment charge for the amount by which the reporting unit’s carrying amount exceeds its fair value. If fair value exceeds the carrying amount, no impairment should be recorded. Any loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Impairment losses on goodwill cannot be reversed once recognized. An entity may still perform the optional qualitative assessment for a reporting unit to determine if it is more likely than not that goodwill is impaired. However, the ASU eliminates the requirement to perform a qualitative assessment for any reporting unit with a zero or negative carrying amount. Therefore, the same one-step impairment assessment will apply to all reporting units. However, for a reporting unit with a zero or negative carrying amount, the ASU adds a requirement to disclose the amount of goodwill allocated to it and the reportable segment in which it is included. For public business entities that are SEC filers, the amendments are effective with their annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Corporation has evaluated the provision of ASU 2017-04 to determine the potential impact of the new standard and has determined that it is not expected to have an impact on its consolidated financial condition or results of operations based on the current circumstances. ASU 2017-13 In September 2017, the FASB issued ASU 2017-13, Revenue Recognition (Topic 605), Revenue from Contracts with Customers (Topic 606), Leases (Topic 840), and Leases (Topic 842). ASU 2017-13 adds SEC paragraphs pursuant to an SEC Staff Announcement made at the July 20, 2017 Emerging Issues Task Force (EITF) meeting. The SEC staff announced that it will not object if an entity that qualifies as a public business entity solely because its financial statements or financial information is included in another entity’s filing with the SEC adopts ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and ASU 2016-02, Leases (Topic 842) using the effective dates applicable to private entities. The amendments represent guidance related to the effective dates of the standards noted above, therefore, the amendments themselves do not have an effective date.

Acquisition of New Windsor Ba25

Acquisition of New Windsor Bancorp, Inc. (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Purchase price consideration in common stock	The following table summarizes the consideration paid for NW Bancorp and the fair value of assets acquired and liabilities assumed as of the acquisition date: Purchase Price Consideration in Common Stock NW Bancorp shares outstanding 1,003,703 Shares paid cash consideration 150,555 Cash consideration (per NW Bancorp share) $ 30.00 Cash portion of purchase price $ 4,519,995 NW Bancorp shares outstanding 1,003,703 Shares paid stock consideration 853,148 Exchange ratio 1.10 Total ACNB shares issued 938,360 ACNB’s share price for purposes of calculation $ 30.50 Equity portion of purchase price $ 28,619,980 Cost of shares owned by buyer $ 150,000 Total consideration paid $ 33,289,975 Allocation of Purchase Price In thousands Total Purchase Price $ 33,290 Fair Value of Assets Acquired Cash and cash equivalents 10,964 Investment securities 21,624 Loans held for sale 1,463 Loans 263,450 Restricted stock 486 Premises and equipment 8,624 Core deposit intangible asset 2,418 Other assets 10,792 Total assets 319,821 Fair Value of Liabilities Assumed Non-interest bearing deposits 80,006 Interest bearing deposits 213,327 Subordinated debt 4,688 Other liabilities 1,782 Total liabilities 299,803 Net Assets Acquired 20,018 Goodwill Recorded in Merger $ 13,272
Fair value adjustments	The table below illustrates the fair value adjustments made to the amortized cost basis in order to present a fair value of the loans acquired. The credit adjustment on purchased credit impaired loans is derived in accordance with ASC 310-30 and represents the portion of the loan balances that has been deemed uncollectible based on the Corporation’s expectations of future cash flows for each respective loan. In thousands Gross amortized cost basis at July 1, 2017 $ 272,646 Interest rate fair value adjustment on pools of homogeneous loans (731 ) Credit fair value adjustment on pools of homogeneous loans (4,501 ) Credit fair value adjustment on purchased credit impaired loans (3,964 ) Fair value of acquired loans at July 1, 2017 $ 263,450
Acquired purchased credit impaired loans receivable	The following table presents the acquired purchased credit impaired loans receivable at the Acquisition Date: In thousands Contractual principal and interest at acquisition $ 13,439 Nonaccretable difference (5,651 ) Expected cash flows at acquisition 7,788 Accretable yield (1,458 ) Fair value of purchased impaired loans $ 6,330
Pro forma results	The following table presents certain pro forma information as if NWSB had been acquired on December 31, 2016. These results combine the historical results of the Corporation in the Corporation’s Consolidated Statements of Income and, while certain adjustments were made for the estimated impact of certain fair value adjustments and other acquisition-related activity, they are not indicative of what would have occurred had the acquisition taken place on December 31, 2016. In particular, no adjustments have been made to eliminate the amount of NWSB’s provision for loan losses that would not have been necessary had the acquired loans been recorded at fair value as of December 31, 2016. The Corporation expects to achieve further operating cost savings and other business synergies as a result of the acquisition which are not reflected in the pro forma amounts below: In thousands For the Year Ended December 31, 2016 Total revenues (net interest income plus noninterest income) $ 102,891 Net Income 13,591

Retirement Benefits (Tables)

Retirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2017
Postemployment Benefits [Abstract]
Schedule of net periodic benefit expense (income)	The components of net periodic benefit expense related to the non-contributory, defined benefit pension plan for the three and nine month periods ended September 30 were as follows: Three Months Ended September 30, Nine Months Ended September 30 In thousands 2017 2016 2017 2016 Service cost $ 210 $ 199 $ 630 $ 597 Interest cost 284 284 852 852 Expected return on plan assets (630 ) (609 ) (1,890 ) (1,824 ) Amortization of net loss 169 172 507 513 Net Periodic Benefit Expense $ 33 $ 46 $ 99 $ 138

Accumulated Other Comprehensi27

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity Note [Abstract]
Schedule of accumulated other comprehensive loss	The components of accumulated other comprehensive loss, net of taxes, are as follows: In thousands Unrealized Gains (Losses) on Securities Pension Liability Accumulated Other Comprehensive Loss BALANCE — SEPTEMBER 30, 2017 $ 40 $ (5,429 ) $ (5,389 ) BALANCE — DECEMBER 31, 2016 $ (266 ) $ (5,758 ) $ (6,024 ) BALANCE — SEPTEMBER 30, 2016 $ 1,679 $ (5,552 ) $ (3,873 )

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Schedule of segment information	Segment information for the nine month periods ended September 30, 2017 and 2016 , is as follows: In thousands Banking Insurance Total 2017 Net interest income and other income from external customers $ 39,536 $ 3,863 $ 43,399 Income before income taxes 9,099 799 9,898 Total assets 1,598,331 9,304 1,607,635 Capital expenditures 1,087 — 1,087 2016 Net interest income and other income from external customers $ 33,871 $ 3,335 $ 37,206 Income before income taxes 10,424 681 11,105 Total assets 1,199,365 9,504 1,208,869 Capital expenditures 2,013 12 2,025 Segment information for the three month periods ended September 30, 2017 and 2016 , is as follows: In thousands Banking Insurance Total 2017 Net interest income and other income from external customers $ 16,321 $ 1,171 $ 17,492 Income before income taxes 2,424 201 2,625 Total assets 1,598,331 9,304 1,607,635 Capital expenditures 284 — 284 2016 Net interest income and other income from external customers $ 11,581 $ 905 $ 12,486 Income before income taxes 3,485 221 3,706 Total assets 1,199,365 9,504 1,208,869 Capital expenditures 326 — 326

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of amortized cost and fair value of securities	Amortized cost and fair value of securities at September 30, 2017 , and December 31, 2016 , were as follows: In thousands Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value SECURITIES AVAILABLE FOR SALE SEPTEMBER 30, 2017 U.S. Government and agencies $ 99,999 $ 37 $ 1,022 $ 99,014 Mortgage-backed securities, residential 36,673 705 27 37,351 State and municipal 14,967 160 11 15,116 Corporate bonds 5,000 112 — 5,112 CRA mutual fund 1,044 — 2 1,042 Stock in other banks 647 110 — 757 $ 158,330 $ 1,124 $ 1,062 $ 158,392 DECEMBER 31, 2016 U.S. Government and agencies $ 81,065 $ 43 $ 1,529 $ 79,579 Mortgage-backed securities, residential 31,272 782 81 31,973 State and municipal 24,514 240 94 24,660 Corporate bonds 5,000 62 — 5,062 CRA mutual fund 1,044 — 9 1,035 Stock in other banks 498 183 — 681 $ 143,393 $ 1,310 $ 1,713 $ 142,990 SECURITIES HELD TO MATURITY SEPTEMBER 30, 2017 U.S. Government and agencies $ 20,004 $ 25 $ 54 $ 19,975 Mortgage-backed securities, residential 27,365 156 123 27,398 $ 47,369 $ 181 $ 177 $ 47,373 DECEMBER 31, 2016 U.S. Government and agencies $ 23,017 $ 26 $ 54 $ 22,989 Mortgage-backed securities, residential 32,551 210 325 32,436 $ 55,568 $ 236 $ 379 $ 55,425
Schedule of unrealized losses and fair value	The following table shows the Corporation’s investments’ gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at September 30, 2017 , and December 31, 2016 : Less than 12 Months 12 Months or More Total In thousands Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses SECURITIES AVAILABLE FOR SALE SEPTEMBER 30, 2017 U.S. Government and agencies $ 65,649 $ 629 $ 15,756 $ 393 $ 81,405 $ 1,022 Mortgage-backed securities, residential 6,783 27 — — 6,783 27 State and municipal 1,441 7 691 4 2,132 11 CRA Mutual Fund 1,042 2 — — 1,042 2 $ 74,915 $ 665 $ 16,447 $ 397 $ 91,362 $ 1,062 DECEMBER 31, 2016 U.S. Government and agencies $ 71,454 $ 1,529 $ — $ — $ 71,454 $ 1,529 Mortgage-backed securities, residential 8,966 81 — — 8,966 81 State and municipal 4,933 94 — — 4,933 94 CRA Mutual Fund 1,035 9 — — 1,035 9 $ 86,388 $ 1,713 $ — $ — $ 86,388 $ 1,713 SECURITIES HELD TO MATURITY SEPTEMBER 30, 2017 U.S. Government and agencies $ 12,948 $ 52 $ 1,998 $ 2 $ 14,946 $ 54 Mortgage-backed securities, residential 10,496 114 1,168 9 11,664 123 $ 23,444 $ 166 $ 3,166 $ 11 $ 26,610 $ 177 DECEMBER 31, 2016 U.S. Government and agencies $ 12,946 $ 54 $ — $ — $ 12,946 $ 54 Mortgage-backed securities, residential 12,956 325 — — 12,956 325 $ 25,902 $ 379 $ — $ — $ 25,902 $ 379
Schedule of amortized cost and fair value by contractual maturity	Amortized cost and fair value at September 30, 2017 , by contractual maturity, where applicable, are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay with or without penalties. Available for Sale Held to Maturity In thousands Amortized Cost Fair Value Amortized Cost Fair Value 1 year or less $ 6,576 $ 6,589 $ 8,004 $ 7,998 Over 1 year through 5 years 97,681 96,972 12,000 11,977 Over 5 years through 10 years 15,709 15,681 — — Over 10 years — — — — Mortgage-backed securities, residential 36,673 37,351 27,365 27,398 CRA mutual fund 1,044 1,042 — — Stock in other banks 647 757 — — $ 158,330 $ 158,392 $ 47,369 $ 47,373

Loans (Tables)

Loans (Tables)	9 Months Ended
	Sep. 30, 2017
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Schedule of classes of loan portfolio summarized by the aggregate risk rating	The following table presents the classes of the loan portfolio summarized by the aggregate pass rating and the classified ratings of special mention, substandard, and doubtful within the Corporation’s internal risk rating system as of September 30, 2017 , and December 31, 2016 : In thousands Pass Special Mention Substandard Doubtful Total SEPTEMBER 30, 2017 Originated Loans Commercial and industrial $ 157,249 $ 3,348 $ 2,060 $ — $ 162,657 Commercial real estate 312,432 19,134 9,355 — 340,921 Commercial real estate construction 31,042 1,009 250 — 32,301 Residential mortgage 352,238 3,895 544 — 356,677 Home equity lines of credit 77,486 352 90 — 77,928 Consumer 14,413 — — — 14,413 Total Originated Loans 944,860 27,738 12,299 — 984,897 Acquired Loans Commercial and industrial 6,123 177 80 — 6,380 Commercial real estate 125,703 13,824 3,225 — 142,752 Commercial real estate construction 7,085 393 — — 7,478 Residential mortgage 58,927 2,932 3,196 — 65,055 Home equity lines of credit 26,726 88 371 — 27,185 Consumer 2,263 358 2 — 2,623 Total Acquired Loans 226,827 17,772 6,874 — 251,473 Total Loans Commercial and industrial 163,372 3,525 2,140 — 169,037 Commercial real estate 438,135 32,958 12,580 — 483,673 Commercial real estate construction 38,127 1,402 250 — 39,779 Residential mortgage 411,165 6,827 3,740 — 421,732 Home equity lines of credit 104,212 440 461 — 105,113 Consumer 16,676 358 2 — 17,036 Total Loans $ 1,171,687 $ 45,510 $ 19,173 $ — $ 1,236,370 DECEMBER 31, 2016 Commercial and industrial $ 134,088 $ 2,355 $ 3,901 $ — $ 140,344 Commercial real estate 291,762 17,376 9,842 — 318,980 Commercial real estate construction 13,606 1,202 463 — 15,271 Residential mortgage 344,048 3,617 874 — 348,539 Home equity lines of credit 69,190 756 126 — 70,072 Consumer 14,704 — — — 14,704 $ 867,398 $ 25,306 $ 15,206 $ — $ 907,910
Schedule of changes In accretable yields of acquired loans	The following table provides changes in accretable yield for all acquired loans accounted for under ASC 310-30. Loans accounted for under ASC 310-20 are not included in this table. In thousands Nine Months Ended September 30, 2017 Balance at beginning of period $ — Acquisitions of impaired loans 1,458 Reclassification from non-accretable differences — Accretion (111 ) Balance at end of period $ 1,347
Summary of information relative to impaired loans by loan portfolio class	The following table summarizes information relative to impaired loans by loan portfolio class as of September 30, 2017 , and December 31, 2016 : Impaired Loans with Allowance Impaired Loans with No Allowance In thousands Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance SEPTEMBER 30, 2017 Commercial and industrial $ 1,353 $ 1,353 $ 698 $ 390 $ 390 Commercial real estate 832 832 117 7,581 7,581 Residential mortgage 377 377 377 101 101 $ 2,562 $ 2,562 $ 1,192 $ 8,072 $ 8,072 DECEMBER 31, 2016 Commercial and industrial $ 948 $ 948 $ 599 $ 1,178 $ 1,178 Commercial real estate — — — 8,764 8,965 Commercial real estate construction — — — 300 300 Residential mortgage 376 376 333 379 379 $ 1,324 $ 1,324 $ 932 $ 10,621 $ 10,822
Summary of information in regards to the average of impaired loans and related income by loan portfolio class	The following table summarizes information in regards to the average of impaired loans and related interest income by loan portfolio class for the three months ended September 30, 2017 and 2016 : Impaired Loans with Allowance Impaired Loans with No Allowance In thousands Average Recorded Investment Interest Income Average Recorded Investment Interest Income SEPTEMBER 30, 2017 Commercial and industrial $ 1,360 $ — $ 734 $ — Commercial real estate 832 — 7,626 80 Commercial real estate construction — — — — Residential mortgage 378 — 101 — $ 2,570 $ — $ 8,461 $ 80 SEPTEMBER 30, 2016 Commercial and industrial $ — $ — $ 1,361 $ 3 Commercial real estate — — 8,156 104 Commercial real estate construction — — 300 — Residential mortgage 374 — 414 4 $ 374 $ — $ 10,231 $ 111 The following table summarizes information in regards to the average of impaired loans and related interest income by loan portfolio class for the nine months ended September 30, 2017 and 2016 : Impaired Loans with Allowance Impaired Loans with No Allowance In thousands Average Recorded Investment Interest Income Average Recorded Investment Interest Income SEPTEMBER 30, 2017 Commercial and industrial $ 1,152 $ — $ 934 $ — Commercial real estate 416 — 8,155 293 Commercial real estate construction — — 75 25 Residential mortgage 377 — 238 15 $ 1,945 $ — $ 9,402 $ 333 SEPTEMBER 30, 2016 Commercial and industrial $ — $ — $ 1,400 $ 3 Commercial real estate — — 8,280 327 Commercial real estate construction — — 337 — Residential mortgage 187 — 435 13 $ 187 $ — $ 10,452 $ 343
Schedule of nonaccrual loans by loan portfolio class	The following table presents nonaccrual loans by loan portfolio class as of September 30, 2017 , and December 31, 2016 , the table below excludes $6.9 million in purchase credit impaired loans, net of unamortized fair value adjustments: In thousands September 30, 2017 December 31, 2016 Commercial and industrial $ 1,743 $ 2,126 Commercial real estate 4,474 1,593 Commercial real estate construction — 300 Residential mortgage 478 483 $ 6,695 $ 4,502
Summary of information relative to trouble debt restructurings by loan portfolio class	The following table summarizes information relative to troubled debt restructurings by loan portfolio class as of September 30, 2017 , and December 31, 2016 : In thousands Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Recorded Investment at Period End SEPTEMBER 30, 2017 Nonaccruing troubled debt restructurings: Commercial real estate $ 4,015 $ 4,073 $ 3,434 Total nonaccruing troubled debt restructurings 4,015 4,073 3,434 Accruing troubled debt restructurings: Commercial real estate 4,577 4,577 3,939 Total accruing troubled debt restructurings 4,577 4,577 3,939 Total Troubled Debt Restructurings $ 8,592 $ 8,650 $ 7,373 DECEMBER 31, 2016 Nonaccruing troubled debt restructurings: Commercial real estate $ 648 $ 648 $ 377 Total nonaccruing troubled debt restructurings 648 648 377 Accruing troubled debt restructurings: Commercial real estate 7,944 8,002 7,171 Residential mortgage 336 336 272 Total accruing troubled debt restructurings 8,280 8,338 7,443 Total Troubled Debt Restructurings $ 8,928 $ 8,986 $ 7,820
Schedule of classes of loan portfolio summarized by the past due status	The following table presents the classes of the loan portfolio summarized by the past due status as of September 30, 2017 , and December 31, 2016 : In thousands 30-59 Days Past Due 60-89 Days Past Due >90 Days Past Due Total Past Due Current Total Loans Receivable Loans Receivable >90 Days and Accruing SEPTEMBER 30, 2017 Originated Loans Commercial and industrial $ 75 $ 1 $ 1,749 $ 1,825 $ 160,832 $ 162,657 $ 6 Commercial real estate — — 1,313 1,313 339,608 340,921 — Commercial real estate construction — 332 — 332 31,969 32,301 — Residential mortgage 397 363 1,977 2,737 353,940 356,677 1,499 Home equity lines of credit 105 50 96 251 77,677 77,928 96 Consumer 65 3 — 68 14,345 14,413 — Total originated loans 642 749 5,135 6,526 978,371 984,897 1,601 Acquired Loans Commercial and industrial — 1 — 1 6,379 6,380 — Commercial real estate — — — — 142,752 142,752 — Commercial real estate construction 76 — — 76 7,402 7,478 — Residential mortgage 298 115 25 438 64,617 65,055 25 Home equity lines of credit 605 — — 605 26,580 27,185 — Consumer 12 — — 12 2,611 2,623 — Total acquired loans 991 116 25 1,132 250,341 251,473 25 Total Loans Commercial and industrial 75 2 1,749 1,826 167,211 169,037 6 Commercial real estate — — 1,313 1,313 482,360 483,673 — Commercial real estate construction 76 332 — 408 39,371 39,779 — Residential mortgage 695 478 2,002 3,175 418,557 421,732 1,524 Home equity lines of credit 710 50 96 856 104,257 105,113 96 Consumer 77 3 — 80 16,956 17,036 — Total Loans $ 1,633 $ 865 $ 5,160 $ 7,658 $ 1,228,712 $ 1,236,370 $ 1,626 DECEMBER 31, 2016 Commercial and industrial $ 26 $ 1 $ 1,178 $ 1,205 $ 139,139 $ 140,344 $ — Commercial real estate 325 674 — 999 317,981 318,980 — Commercial real estate construction — — 300 300 14,971 15,271 — Residential mortgage 2,866 657 1,413 4,936 343,603 348,539 937 Home equity lines of credit 310 56 408 774 69,298 70,072 408 Consumer 31 47 — 78 14,626 14,704 — Total loans $ 3,558 $ 1,435 $ 3,299 $ 8,292 $ 899,618 $ 907,910 $ 1,345
Summary of allowance for loan losses and recorded investment in loans receivable	The following tables summarize the allowance for loan losses and recorded investment in loans receivable: In thousands Commercial and Industrial Commercial Real Estate Commercial Real Estate Construction Residential Mortgage Home Equity Lines of Credit Consumer Unallocated Total AS OF AND FOR THE PERIOD ENDED SEPTEMBER 30, 2017 Allowance for Loan Losses Beginning balance - July 1, 2017 $ 3,246 $ 5,210 $ 135 $ 3,368 $ 607 $ 815 $ 767 $ 14,148 Charge-offs (60 ) — — (15 ) (9 ) (18 ) — (102 ) Recoveries 8 — 40 10 — 1 — 59 Provisions 73 195 (31 ) (101 ) 29 12 (177 ) — Ending balance - September 30, 2017 $ 3,267 $ 5,405 $ 144 $ 3,262 $ 627 $ 810 $ 590 $ 14,105 Beginning balance - January 1, 2017 $ 3,055 $ 4,968 $ 147 $ 3,478 $ 648 $ 923 $ 975 $ 14,194 Charge-offs (129 ) — — (32 ) (9 ) (102 ) — (272 ) Recoveries 17 61 40 52 — 13 — 183 Provisions 324 376 (43 ) (236 ) (12 ) (24 ) (385 ) — Ending balance - September 30, 2017 $ 3,267 $ 5,405 $ 144 $ 3,262 $ 627 $ 810 $ 590 $ 14,105 Ending balance: individually evaluated for impairment $ 698 $ 117 $ — $ 377 $ — $ — $ — $ 1,192 Ending balance: collectively evaluated for impairment $ 2,569 $ 5,288 $ 144 $ 2,885 $ 627 $ 810 $ 590 $ 12,913 Loans Receivable Ending balance $ 169,037 $ 483,673 $ 39,779 $ 421,732 $ 105,113 $ 17,036 $ — $ 1,236,370 Ending balance: individually evaluated for impairment $ 1,743 $ 8,413 $ — $ 478 $ — $ — $ — $ 10,634 Ending balance: collectively evaluated for impairment $ 167,294 $ 475,260 $ 39,779 $ 421,254 $ 105,113 $ 17,036 $ — $ 1,225,736 AS OF AND FOR THE PERIOD ENDED SEPTEMBER 30, 2016 Allowance for Loan Losses Beginning Balance - July 1, 2016 $ 2,557 $ 5,433 $ 134 $ 3,311 $ 607 $ 952 $ 1,642 $ 14,636 Charge-offs (131 ) — — (6 ) — (28 ) — (165 ) Recoveries 5 — — 8 — 4 — 17 Provisions (80 ) (60 ) 11 (46 ) 2 (11 ) 184 — Ending balance - September 30, 2016 $ 2,351 $ 5,373 $ 145 $ 3,267 $ 609 $ 917 $ 1,826 $ 14,488 Beginning Balance - January 1, 2016 $ 2,508 $ 5,216 $ 112 $ 3,349 $ 619 $ 1,083 $ 1,860 $ 14,747 Charge-offs (221 ) — (135 ) (45 ) (9 ) (50 ) — (460 ) Recoveries 44 — 132 14 — 11 — 201 Provisions 20 157 36 (51 ) (1 ) (127 ) (34 ) — Ending balance - September 30, 2016 $ 2,351 $ 5,373 $ 145 $ 3,267 $ 609 $ 917 $ 1,826 $ 14,488 Ending balance: individually evaluated for impairment $ — $ — $ — $ 167 $ — $ — $ — $ 167 Ending balance: collectively evaluated for impairment $ 2,351 $ 5,373 $ 145 $ 3,100 $ 609 $ 917 $ 1,826 $ 14,321 Loans Receivable Ending balance $ 122,926 $ 309,161 $ 13,243 $ 346,422 $ 65,689 $ 14,582 $ — $ 872,023 Ending balance: individually evaluated for impairment $ 1,249 $ 8,042 $ 300 $ 759 $ — $ — $ — $ 10,350 Ending balance: collectively evaluated for impairment $ 121,677 $ 301,119 $ 12,943 $ 345,663 $ 65,689 $ 14,582 $ — $ 861,673 In thousands Commercial and Industrial Commercial Real Estate Commercial Real Estate Construction Residential Mortgage Home Equity Lines of Credit Consumer Unallocated Total AS OF DECEMBER 31, 2016 Allowance for Loan Losses Ending balance $ 3,055 $ 4,968 $ 147 $ 3,478 $ 648 $ 923 $ 975 $ 14,194 Ending balance: individually evaluated for impairment $ 599 $ — $ — $ 333 $ — $ — $ — $ 932 Ending balance: collectively evaluated for impairment $ 2,456 $ 4,968 $ 147 $ 3,145 $ 648 $ 923 $ 975 $ 13,262 Loans Receivable Ending balance $ 140,344 $ 318,980 $ 15,271 $ 348,539 $ 70,072 $ 14,704 $ — $ 907,910 Ending balance: individually evaluated for impairment $ 2,126 $ 8,764 $ 300 $ 755 $ — $ — $ — $ 11,945 Ending balance: collectively evaluated for impairment $ 138,218 $ 310,216 $ 14,971 $ 347,784 $ 70,072 $ 14,704 $ — $ 895,965

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of fair value measurements by level within the fair value hierarchy and the basis of measurement used	For assets measured at fair value, the fair value measurements by level within the fair value hierarchy, and the basis of measurement used, at September 30, 2017 , and December 31, 2016 , are as follows: September 30, 2017 In thousands Basis Total Level 1 Level 2 Level 3 U.S. Government and agencies $ 99,014 $ — $ 99,014 $ — Mortgage-backed securities, residential 37,351 — 37,351 — State and municipal 15,116 — 15,116 — Corporate bonds 5,112 — 5,112 — CRA mutual fund 1,042 1,042 — — Stock in other banks 757 757 — — Total securities available for sale Recurring $ 158,392 $ 1,799 $ 156,593 $ — Impaired loans Nonrecurring $ 5,462 $ — $ — $ 5,462 December 31, 2016 In thousands Basis Total Level 1 Level 2 Level 3 U.S. Government and agencies $ 79,579 $ — $ 79,579 $ — Mortgage-backed securities, residential 31,973 — 31,973 — State and municipal 24,660 — 24,660 — Corporate bonds 5,062 — 5,062 — CRA mutual fund 1,035 1,035 — — Stock in other banks 681 681 — — Total securities available for sale Recurring $ 142,990 $ 1,716 $ 141,274 $ — Impaired loans Nonrecurring $ 4,406 $ — $ — $ 4,406
Schedule of additional quantitative information about assets measured at fair value on a nonrecurring basis	The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis for which the Corporation has utilized Level 3 inputs to determine fair value: Quantitative Information about Level 3 Fair Value Measurements Dollars in thousands Fair Value Estimate Valuation Technique Unobservable Input Range Weighted Average September 30, 2017 Impaired loans $ 5,462 Appraisal of collateral (a) Appraisal adjustments (b) (10) - (50)% (34)% December 31, 2016 Impaired loans $ 4,406 Appraisal of collateral (a) Appraisal adjustments (b) (10) - (50)% (39)% (a) Fair value is generally determined through management’s estimate or independent third-party appraisals of the underlying collateral, which generally includes various Level 3 inputs which are not observable. (b) Appraisals may be adjusted downward by management for qualitative factors such as economic conditions and estimated liquidation expenses. The range of liquidation expenses and other appraisal adjustments are presented as a percentage of the appraisal. Higher downward adjustments are caused by negative changes to the collateral or conditions in the real estate market, actual offers or sales contracts received, and/or age of the appraisal.
Schedule of carrying amount, fair value and placement in the fair value hierarchy	The following presents the carrying amount, fair value, and placement in the fair value hierarchy of the Corporation’s financial instruments as of September 30, 2017 , and December 31, 2016 : September 30, 2017 In thousands Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and due from banks $ 17,882 $ 17,882 $ 8,131 $ 9,751 $ — Interest-bearing deposits in banks 31,609 31,609 31,609 — — Investment securities available for sale 158,392 158,392 1,799 156,593 — Investment securities held to maturity 47,369 47,373 — 47,373 — Loans held for sale 1,873 1,873 — 1,873 — Loans, less allowance for loan losses 1,222,265 1,205,807 — — 1,205,807 Accrued interest receivable 3,795 3,795 — 3,795 — Restricted investment in bank stocks 4,821 4,821 — 4,821 — Financial liabilities: Deposits 1,311,884 1,307,677 — 1,307,677 — Short-term borrowings 33,806 33,806 — 33,806 — Long-term borrowings 96,850 97,129 — 97,129 — Accrued interest payable 1,072 1,072 — 1,072 — Off-balance sheet financial instruments — — — — — December 31, 2016 In thousands Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and due from banks $ 13,796 $ 13,796 $ 6,921 $ 6,875 $ — Interest-bearing deposits in banks 5,135 5,135 5,135 — — Investment securities available for sale 142,990 142,990 1,716 141,274 — Investment securities held to maturity 55,568 55,425 — 55,425 — Loans held for sale 1,770 1,770 — 1,770 — Loans, less allowance for loan losses 893,176 888,169 — — 888,169 Accrued interest receivable 3,158 3,158 — 3,158 — Restricted investment in bank stocks 4,349 4,349 — 4,349 — Financial liabilities: Deposits 967,621 967,236 — 967,236 — Short-term borrowings 34,590 34,590 — 34,590 — Long-term borrowings 74,250 75,029 — 75,029 — Accrued interest payable 837 837 — 837 — Off-balance sheet financial instruments — — — — —

Securities Sold Under Agreeme32

Securities Sold Under Agreements to Repurchase (Repurchase Agreements) (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure of Repurchase Agreements [Abstract]
Schedule of short-term borrowings subject to an enforceable master netting arrangement or repurchase agreement	The following table presents the short-term borrowings subject to an enforceable master netting arrangement or repurchase agreement as of September 30, 2017 , and December 31, 2016 : Gross Amounts Not Offset in the Statements of Condition In thousands Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statements of Condition Net Amounts of Liabilities Presented in the Statements of Condition Financial Instruments Cash Collateral Pledged Net Amount September 30, 2017 Repurchase agreements Commercial customers and government entities (a) $ 33,806 $ — $ 33,806 $ (33,806 ) $ — $ — December 31, 2016 Repurchase agreements Commercial customers and government entities (a) $ 34,590 $ — $ 34,590 $ (34,590 ) $ — $ — (a) As of September 30, 2017 , and December 31, 2016 , the fair value of securities pledged in connection with repurchase agreements was $41,149,000 and $41,406,000 , respectively.
Schedule of remaining contractual maturity of the master netting arrangement or repurchase agreements	The following table presents the remaining contractual maturity of the master netting arrangement or repurchase agreements as of September 30, 2017 : Remaining Contractual Maturity of the Agreements In thousands Overnight and Continuous Up to 30 Days 30 - 90 Days Greater than 90 Days Total Repurchase agreements and repurchase-to-maturity transactions U.S. Treasury and agency securities $ 33,806 $ — $ — $ — $ 33,806 Total $ 33,806 $ — $ — $ — $ 33,806

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of long-term debt outstanding	The Corporation had long-term debt outstanding as follows: In thousands September 30, 2017 December 31, 2016 FHLB Advances $ 87,250 $ 74,250 Loan Payable to local bank 4,600 — Trust preferred subordinated debt 5,000 — $ 96,850 $ 74,250

Goodwill and Other Intangible34

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of finite-lived intangible assets	The carrying value and accumulated amortization of the intangible assets (RIG customer lists and NW Bancorp core deposit intangibles) are as follows: In thousands Gross carrying amount Accumulated amortization RIG amortized intangible assets $ 6,667 $ 6,223 NW Bancorp core deposit intangibles 2,418 110

Basis of Presentation and Nat35

Basis of Presentation and Nature of Operations (Details)	9 Months Ended
	Sep. 30, 2017bank
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of retail banking office locations, ACNB	22
Number of retail banking office locations, NWSB	7

Acquisition of New Windsor Ba36

Acquisition of New Windsor Bancorp, Inc. - Narrative (Details)	Jul. 01, 2017USD ($)bank$ / sharesshares	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)bank	Sep. 30, 2016USD ($)	Jun. 30, 2017$ / shares	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Number of retail banking office locations, NWSB | bank				7
Goodwill		$ 19,580,000	$ 6,308,000	$ 19,580,000	$ 6,308,000		$ 6,308,000
Merger related expenses		4,305,000	$ 0	$ 4,675,000	$ 0
Core deposit intangibles
Business Acquisition [Line Items]
Amortization period				10 years
New Windsor
Business Acquisition [Line Items]
Number of retail banking office locations, NWSB | bank	7
Fair Value of total assets acquired	$ 319,821,000
Fair value of total loans acquired	263,450,000
Fair value of total deposits acquired	293,300,000
Goodwill	13,272,000	$ 13,272,000		$ 13,272,000
Cash portion of purchase price	$ 4,519,995
Percent of post transaction outstanding shares of the Corporation's common stock issued in merger	13.00%
Total consideration paid	$ 33,289,975
ACNB’s share price for purposes of calculation (in dollars per share) | $ / shares	$ 30.50					$ 30.50
Loans receivable, gross amortized cost basis	$ 272,646,000
Interest rate fair value discount	731,000
Credit fair value discount	4,501,000
New Windsor | Long-term Borrowings
Business Acquisition [Line Items]
Liabilities, fair value discount	$ 312,500
New Windsor | Core deposit intangibles
Business Acquisition [Line Items]
Amortization period	10 years			10 years
New Windsor | Investment Securities Available-for-sale
Business Acquisition [Line Items]
Assets, fair value premium (discount)	$ 361,000
New Windsor | Time Deposits
Business Acquisition [Line Items]
Assets, fair value premium (discount)	$ (847,500)
New Windsor | Common Stock
Business Acquisition [Line Items]
Shares of common stock issued in merger (in shares) | shares	938,360

Acquisition of New Windsor Ba37

Acquisition of New Windsor Bancorp, Inc. - Purchase Price Consideration in Common Stock (Details) - USD ($)	Jul. 01, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
NW Bancorp shares outstanding		7,019,645		6,064,138	6,061,062
Fair Value of Liabilities Assumed
Goodwill Recorded in Merger		$ 19,580,000		$ 6,308,000	$ 6,308,000
NW Bancorp
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Cash consideration (per NW Bancorp share) (in dollars per share)	$ 30
Cash portion of purchase price	$ 4,519,995
ACNB’s share price for purposes of calculation (in dollars per share)	$ 30.50		$ 30.50
Equity portion of purchase price	$ 28,619,980
Cost of shares owned by buyer	150,000
Total consideration paid	33,289,975
Fair Value of Assets Acquired
Cash and cash equivalents	10,964,000
Investment securities	21,624,000
Loans held for sale	1,463,000
Loans	263,450,000
Restricted stock	486,000
Premises and equipment	8,624,000
Core deposit intangible asset	2,418,000
Other assets	10,792,000
Total assets	319,821,000
Fair Value of Liabilities Assumed
Non-interest bearing deposits	80,006,000
Interest bearing deposits	213,327,000
Subordinated debt	4,688,000
Other liabilities	1,782,000
Total liabilities	299,803,000
Net Assets Acquired	20,018,000
Goodwill Recorded in Merger	$ 13,272,000	$ 13,272,000
NW Bancorp | Common Stock
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Exchange ratio	1.10
Total ACNB shares issued	938,360
NW Bancorp | NW Bancorp
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
NW Bancorp shares outstanding	1,003,703
Shares paid cash consideration	150,555
Shares paid stock consideration	853,148

Acquisition of New Windsor Ba38

Acquisition of New Windsor Bancorp, Inc. - Fair Value Adjustments (Details) - New Windsor $ in Thousands	Jul. 01, 2017USD ($)
Business Acquisition [Line Items]
Gross amortized cost basis at July 1, 2017	$ 272,646
Interest rate fair value adjustment on pools of homogeneous loans	(731)
Credit fair value adjustment on pools of homogeneous loans	(4,501)
Fair value of acquired loans at July 1, 2017	263,450
Purchased credit impaired loans
Business Acquisition [Line Items]
Credit fair value adjustment on pools of homogeneous loans	$ (3,964)

Acquisition of New Windsor Ba39

Acquisition of New Windsor Bancorp, Inc. - Acquired Purchased Credit Impaired Loans Receivable (Details) - New Windsor $ in Thousands	Jul. 01, 2017USD ($)
Business Acquisition [Line Items]
Contractual principal and interest at acquisition	$ 13,439
Nonaccretable difference	(5,651)
Expected cash flows at acquisition	7,788
Accretable yield	(1,458)
Fair value of purchased impaired loans	$ 6,330

Acquisition of New Windsor Ba40

Acquisition of New Windsor Bancorp, Inc. - Pro forma information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Business Combinations [Abstract]
Total revenues (net interest income plus noninterest income)	$ 102,891
Net Income	$ 13,591

Earnings Per Share and Restri41

Earnings Per Share and Restricted Stock Plan (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Weighted average shares of common stock outstanding (in shares)	7,004,346	6,057,508	6,383,149	6,048,216
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under plan (in shares)			19,301
Shares vested (in shares)			12,693
Shares expected to vest over next year (in shares)	6,608		6,608
Compensation expense	$ 0	$ 0	$ 120,000	$ 59,000

Retirement Benefits (Details)

Retirement Benefits (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)person	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)person	Sep. 30, 2016USD ($)
Postemployment Benefits [Abstract]
Service cost	$ 210	$ 199	$ 630	$ 597
Interest cost	284	284	852	852
Expected return on plan assets	(630)	(609)	(1,890)	(1,824)
Amortization of net loss	169	172	507	513
Net Periodic Benefit Expense	$ 33	$ 46	$ 99	$ 138
Number of active, vested, terminated and retired persons in the Plan | person	358		358

Guarantees (Details)

Guarantees (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Guarantor Obligations [Line Items]
Line of credit facility expiration period	1 year
Standby Letters of Credit
Guarantor Obligations [Line Items]
Guarantees amount	$ 6,974

Accumulated Other Comprehensi44

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Components of accumulated other comprehensive loss	$ 153,256	$ 120,061	$ 120,754	$ 114,715
Unrealized Gains (Losses) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Components of accumulated other comprehensive loss	40	(266)	1,679
Pension Liability
Accumulated Other Comprehensive Income (Loss) [Line Items]
Components of accumulated other comprehensive loss	(5,429)	(5,758)	(5,552)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Components of accumulated other comprehensive loss	$ (5,389)	$ (6,024)	$ (3,873)	$ (4,726)

Segment Reporting (Details)

Segment Reporting (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)segment	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Segment Reporting [Abstract]
Number of reporting segments | segment			2
Segment Reporting Information [Line Items]
Net interest income and other income from external customers	$ 17,492	$ 12,486	$ 43,399	$ 37,206
Income before income taxes	2,625	3,706	9,898	11,105
Total assets	1,607,635	1,208,869	1,607,635	1,208,869	$ 1,206,320
Capital expenditures	284	326	1,087	2,025
Banking
Segment Reporting Information [Line Items]
Net interest income and other income from external customers	16,321	11,581	39,536	33,871
Income before income taxes	2,424	3,485	9,099	10,424
Total assets	1,598,331	1,199,365	1,598,331	1,199,365
Capital expenditures	284	326	1,087	2,013
Insurance
Segment Reporting Information [Line Items]
Net interest income and other income from external customers	1,171	905	3,863	3,335
Income before income taxes	201	221	799	681
Total assets	9,304	9,504	9,304	9,504
Capital expenditures	$ 0	$ 0	$ 0	$ 12
Customer lists
Segment Reporting Information [Line Items]
Amortization period			10 years
Core deposit intangibles
Segment Reporting Information [Line Items]
Amortization period			10 years

Securities - Schedule of Amorti

Securities - Schedule of Amortized Cost and Fair Value of Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
SECURITIES AVAILABLE FOR SALE
Amortized Cost	$ 158,330	$ 143,393
Gross Unrealized Gains	1,124	1,310
Gross Unrealized Losses	1,062	1,713
Fair Value	158,392	142,990	$ 143,940
SECURITIES HELD TO MATURITY
Amortized Cost	47,369	55,568	57,562
Gross Unrealized Gains	181	236
Gross Unrealized Losses	177	379
Fair Value	47,373	55,425	$ 58,566
U.S. Government and agencies
SECURITIES AVAILABLE FOR SALE
Amortized Cost	99,999	81,065
Gross Unrealized Gains	37	43
Gross Unrealized Losses	1,022	1,529
Fair Value	99,014	79,579
SECURITIES HELD TO MATURITY
Amortized Cost	20,004	23,017
Gross Unrealized Gains	25	26
Gross Unrealized Losses	54	54
Fair Value	19,975	22,989
Mortgage-backed securities, residential
SECURITIES AVAILABLE FOR SALE
Amortized Cost	36,673	31,272
Gross Unrealized Gains	705	782
Gross Unrealized Losses	27	81
Fair Value	37,351	31,973
SECURITIES HELD TO MATURITY
Amortized Cost	27,365	32,551
Gross Unrealized Gains	156	210
Gross Unrealized Losses	123	325
Fair Value	27,398	32,436
State and municipal
SECURITIES AVAILABLE FOR SALE
Amortized Cost	14,967	24,514
Gross Unrealized Gains	160	240
Gross Unrealized Losses	11	94
Fair Value	15,116	24,660
Corporate bonds
SECURITIES AVAILABLE FOR SALE
Amortized Cost	5,000	5,000
Gross Unrealized Gains	112	62
Gross Unrealized Losses	0	0
Fair Value	5,112	5,062
CRA mutual fund
SECURITIES AVAILABLE FOR SALE
Amortized Cost	1,044	1,044
Gross Unrealized Gains	0	0
Gross Unrealized Losses	2	9
Fair Value	1,042	1,035
Stock in other banks
SECURITIES AVAILABLE FOR SALE
Amortized Cost	647	498
Gross Unrealized Gains	110	183
Gross Unrealized Losses	0	0
Fair Value	$ 757	$ 681

Securities - Schedule of Unreal

Securities - Schedule of Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
SECURITIES AVAILABLE FOR SALE
Fair Value, Less than 12 Months	$ 74,915	$ 86,388
Unrealized Losses, Less than 12 Months	665	1,713
Fair Value, 12 Months or More	16,447	0
Unrealized Losses, 12 Months or More	397	0
Total Fair Value	91,362	86,388
Total Unrealized Losses	1,062	1,713
SECURITIES HELD TO MATURITY
Fair Value, Less than 12 Months	23,444	25,902
Unrealized Losses, Less than 12 Months	166	379
Fair Value, 12 Months or More	3,166	0
Unrealized Losses, 12 Months or More	11	0
Total Fair Value	26,610	25,902
Total Unrealized Losses	177	379
U.S. Government and agencies
SECURITIES AVAILABLE FOR SALE
Fair Value, Less than 12 Months	65,649	71,454
Unrealized Losses, Less than 12 Months	629	1,529
Fair Value, 12 Months or More	15,756	0
Unrealized Losses, 12 Months or More	393	0
Total Fair Value	81,405	71,454
Total Unrealized Losses	1,022	1,529
SECURITIES HELD TO MATURITY
Fair Value, Less than 12 Months	12,948	12,946
Unrealized Losses, Less than 12 Months	52	54
Fair Value, 12 Months or More	1,998	0
Unrealized Losses, 12 Months or More	2	0
Total Fair Value	14,946	12,946
Total Unrealized Losses	54	54
Mortgage-backed securities, residential
SECURITIES AVAILABLE FOR SALE
Fair Value, Less than 12 Months	6,783	8,966
Unrealized Losses, Less than 12 Months	27	81
Fair Value, 12 Months or More	0	0
Unrealized Losses, 12 Months or More	0	0
Total Fair Value	6,783	8,966
Total Unrealized Losses	27	81
SECURITIES HELD TO MATURITY
Fair Value, Less than 12 Months	10,496	12,956
Unrealized Losses, Less than 12 Months	114	325
Fair Value, 12 Months or More	1,168	0
Unrealized Losses, 12 Months or More	9	0
Total Fair Value	11,664	12,956
Total Unrealized Losses	123	325
State and municipal
SECURITIES AVAILABLE FOR SALE
Fair Value, Less than 12 Months	1,441	4,933
Unrealized Losses, Less than 12 Months	7	94
Fair Value, 12 Months or More	691	0
Unrealized Losses, 12 Months or More	4	0
Total Fair Value	2,132	4,933
Total Unrealized Losses	11	94
CRA Mutual Fund
SECURITIES AVAILABLE FOR SALE
Fair Value, Less than 12 Months	1,042	1,035
Unrealized Losses, Less than 12 Months	2	9
Fair Value, 12 Months or More	0	0
Unrealized Losses, 12 Months or More	0	0
Total Fair Value	1,042	1,035
Total Unrealized Losses	$ 2	$ 9

Securities - Narrative (Details

Securities - Narrative (Details) $ in Thousands	Sep. 30, 2017USD ($)Security	Dec. 31, 2016USD ($)
Schedule of Available-for-sale Securities [Line Items]
Carrying value of securities pledged as collateral | $	$ 177,259	$ 134,763
U.S. Government and agencies
Schedule of Available-for-sale Securities [Line Items]
Number of available-for-sale securities with unrealized losses	56
Percentage of amortized cost	4.00%
Number of available-for-sale securities, in continuous loss positions for 12 months or more	9
Schedule of Held-to-maturity Securities [Line Items]
Number of held to maturity securities with unrealized losses	8
Percentage of amortized cost	1.00%
Number of held to maturity securities, in continuous loss position for 12 months or more	1
Mortgage-backed securities, residential
Schedule of Available-for-sale Securities [Line Items]
Number of available-for-sale securities, not in continuous loss position for 12 months or more	8
Percentage of amortized cost	1.00%
Schedule of Held-to-maturity Securities [Line Items]
Number of held to maturity securities with unrealized losses	13
Percentage of amortized cost	2.00%
Number of held to maturity securities, in continuous loss position for 12 months or more	1
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Number of available-for-sale securities with unrealized losses	9
Percentage of amortized cost	2.00%
Number of available-for-sale securities, in continuous loss positions for 12 months or more	3
CRA Mutual Fund
Schedule of Available-for-sale Securities [Line Items]
Percentage of amortized cost	1.00%

Securities - Schedule of Amor49

Securities - Schedule of Amortized Cost and Fair Value by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Available for Sale Amortized Cost
1 year or less	$ 6,576
Over 1 year through 5 years	97,681
Over 5 years through 10 years	15,709
Over 10 years	0
Total amortized cost	158,330	$ 143,393
Available for Sale Fair Value
1 year or less	6,589
Over 1 year through 5 years	96,972
Over 5 years through 10 years	15,681
Over 10 years	0
Total securities available for sale	158,392	142,990	$ 143,940
Held-to-Maturity Amortized Cost
1 year or less	8,004
Over 1 year through 5 years	12,000
Over 5 years through 10 years	0
Over 10 years	0
Total amortized costs	47,369	55,568	57,562
Held-to-Maturity Fair Value
1 year or less	7,998
Over 1 year through 5 years	11,977
Over 5 years through 10 years	0
Over 10 years	0
Securities held to maturity, fair value	47,373	55,425	$ 58,566
Mortgage-backed securities, residential
Available for Sale Amortized Cost
Without single maturity date	36,673
Total amortized cost	36,673	31,272
Available for Sale Fair Value
Without single maturity date	37,351
Total securities available for sale	37,351	31,973
Held-to-Maturity Amortized Cost
Without single maturity date	27,365
Total amortized costs	27,365	32,551
Held-to-Maturity Fair Value
Without single maturity date	27,398
Securities held to maturity, fair value	27,398	32,436
CRA mutual fund
Available for Sale Amortized Cost
Without single maturity date	1,044
Total amortized cost	1,044	1,044
Available for Sale Fair Value
Without single maturity date	1,042
Total securities available for sale	1,042	1,035
Held-to-Maturity Amortized Cost
Without single maturity date	0
Held-to-Maturity Fair Value
Without single maturity date	0
Stock in other banks
Available for Sale Amortized Cost
Without single maturity date	647
Total amortized cost	647	498
Available for Sale Fair Value
Without single maturity date	757
Total securities available for sale	757	$ 681
Held-to-Maturity Amortized Cost
Without single maturity date	0
Held-to-Maturity Fair Value
Without single maturity date	$ 0

Loans - Narrative (Details)

Loans - Narrative (Details) $ in Thousands	Jul. 01, 2017USD ($)	Jun. 30, 2017Contract	Sep. 30, 2017USD ($)Contract	Dec. 31, 2016USD ($)Contract	Dec. 31, 2013Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Period for order of valuations (at least)			18 months
Number of loans moved to nonaccrual status		2
Number of troubled debt restructured loan paid off			1	1
Number of loans which has periodic late payments			1
Number of loans classified as troubled debt restructured loans with active forbearance agreements			2
Number of forbearance agreements negotiated					1
Consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process | $			$ 1,109	$ 471
Residential mortgage and commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold period past due to discontinue accrual interest on financing receivable			90 days
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold period past due for write-off of financing receivable (no later than)			120 days
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Period of financing receivable, updated valuation on real estate secured loans, 90 days past due			90 days
Number of previous months with no updated valuation completed for corporation to update valuation			12 months
Impaired financing receivable, valuation on real estate collateralized loans			30 days
Entity Loan Modification Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from paid off troubled debt restructured loans | $			$ 283	$ 74
New Windsor
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest rate fair value discount | $	$ 731
Credit fair value discount | $	$ 4,501
Maximum | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, term			20 years
Financing receivable, loan to value ratio of appraised value of property			80.00%
Maximum | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, term			30 years
Financing receivable, loan to value ratio of appraised value of property			80.00%
Maximum | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, term			20 years
Financing receivable, loan to value ratio of appraised value of property			90.00%

Loans - Schedule of Classes of

Loans - Schedule of Classes of the Loan Portfolio Summarized by the Aggregate Risk Rating (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 1,236,370	$ 907,910	$ 872,023
Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,171,687	867,398
Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	45,510	25,306
Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	19,173	15,206
Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	169,037	140,344	122,926
Commercial and industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	163,372	134,088
Commercial and industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,525	2,355
Commercial and industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2,140	3,901
Commercial and industrial | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	483,673	318,980	309,161
Commercial real estate | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	438,135	291,762
Commercial real estate | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	32,958	17,376
Commercial real estate | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	12,580	9,842
Commercial real estate | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial real estate construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	39,779	15,271	13,243
Commercial real estate construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	38,127	13,606
Commercial real estate construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,402	1,202
Commercial real estate construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	250	463
Commercial real estate construction | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	421,732	348,539	346,422
Residential mortgage | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	411,165	344,048
Residential mortgage | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	6,827	3,617
Residential mortgage | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,740	874
Residential mortgage | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	105,113	70,072	65,689
Home equity lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	104,212	69,190
Home equity lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	440	756
Home equity lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	461	126
Home equity lines of credit | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	17,036	14,704	$ 14,582
Consumer | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	16,676	14,704
Consumer | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	358	0
Consumer | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2	0
Consumer | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	$ 0
Originated Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	984,897
Originated Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	944,860
Originated Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	27,738
Originated Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	12,299
Originated Loans | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Originated Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	162,657
Originated Loans | Commercial and industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	157,249
Originated Loans | Commercial and industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,348
Originated Loans | Commercial and industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2,060
Originated Loans | Commercial and industrial | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Originated Loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	340,921
Originated Loans | Commercial real estate | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	312,432
Originated Loans | Commercial real estate | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	19,134
Originated Loans | Commercial real estate | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	9,355
Originated Loans | Commercial real estate | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Originated Loans | Commercial real estate construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	32,301
Originated Loans | Commercial real estate construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	31,042
Originated Loans | Commercial real estate construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,009
Originated Loans | Commercial real estate construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	250
Originated Loans | Commercial real estate construction | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Originated Loans | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	356,677
Originated Loans | Residential mortgage | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	352,238
Originated Loans | Residential mortgage | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,895
Originated Loans | Residential mortgage | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	544
Originated Loans | Residential mortgage | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Originated Loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	77,928
Originated Loans | Home equity lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	77,486
Originated Loans | Home equity lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	352
Originated Loans | Home equity lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	90
Originated Loans | Home equity lines of credit | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Originated Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	14,413
Originated Loans | Consumer | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	14,413
Originated Loans | Consumer | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Originated Loans | Consumer | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Originated Loans | Consumer | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	251,473
Acquired Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	226,827
Acquired Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	17,772
Acquired Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	6,874
Acquired Loans | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Acquired Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	6,380
Acquired Loans | Commercial and industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	6,123
Acquired Loans | Commercial and industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	177
Acquired Loans | Commercial and industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	80
Acquired Loans | Commercial and industrial | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Acquired Loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	142,752
Acquired Loans | Commercial real estate | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	125,703
Acquired Loans | Commercial real estate | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	13,824
Acquired Loans | Commercial real estate | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,225
Acquired Loans | Commercial real estate | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Acquired Loans | Commercial real estate construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	7,478
Acquired Loans | Commercial real estate construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	7,085
Acquired Loans | Commercial real estate construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	393
Acquired Loans | Commercial real estate construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Acquired Loans | Commercial real estate construction | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Acquired Loans | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	65,055
Acquired Loans | Residential mortgage | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	58,927
Acquired Loans | Residential mortgage | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2,932
Acquired Loans | Residential mortgage | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,196
Acquired Loans | Residential mortgage | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Acquired Loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	27,185
Acquired Loans | Home equity lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	26,726
Acquired Loans | Home equity lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	88
Acquired Loans | Home equity lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	371
Acquired Loans | Home equity lines of credit | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Acquired Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2,623
Acquired Loans | Consumer | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2,263
Acquired Loans | Consumer | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	358
Acquired Loans | Consumer | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2
Acquired Loans | Consumer | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 0

Loans - Schedule of Change in A

Loans - Schedule of Change in Accretable Yields of Acquired Loans (Details) - Acquired Loans Accounted For Under ASC 310-30 $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 0
Acquisitions of impaired loans	1,458
Reclassification from non-accretable differences	0
Accretion	(111)
Balance at end of period	$ 1,347

Loans - Summary of Impaired Loa

Loans - Summary of Impaired Loans by Loan Portfolio Class (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Recorded Investment	$ 2,562	$ 1,324
Impaired Loans with Allowance: Unpaid Principal Balance	2,562	1,324
Impaired Loans with Allowance: Related Allowance	1,192	932
Impaired Loans with No Allowance: Recorded Investment	8,072	10,621
Impaired Loans with No Allowance: Unpaid Principal Balance	8,072	10,822
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Recorded Investment	1,353	948
Impaired Loans with Allowance: Unpaid Principal Balance	1,353	948
Impaired Loans with Allowance: Related Allowance	698	599
Impaired Loans with No Allowance: Recorded Investment	390	1,178
Impaired Loans with No Allowance: Unpaid Principal Balance	390	1,178
Commercial real estate
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Recorded Investment	832	0
Impaired Loans with Allowance: Unpaid Principal Balance	832	0
Impaired Loans with Allowance: Related Allowance	117	0
Impaired Loans with No Allowance: Recorded Investment	7,581	8,764
Impaired Loans with No Allowance: Unpaid Principal Balance	7,581	8,965
Commercial real estate construction
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Recorded Investment		0
Impaired Loans with Allowance: Unpaid Principal Balance		0
Impaired Loans with Allowance: Related Allowance		0
Impaired Loans with No Allowance: Recorded Investment		300
Impaired Loans with No Allowance: Unpaid Principal Balance		300
Residential mortgage
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Recorded Investment	377	376
Impaired Loans with Allowance: Unpaid Principal Balance	377	376
Impaired Loans with Allowance: Related Allowance	377	333
Impaired Loans with No Allowance: Recorded Investment	101	379
Impaired Loans with No Allowance: Unpaid Principal Balance	$ 101	$ 379

Loans - Summary of Average of I

Loans - Summary of Average of Impaired Loans and Related Interest Income by Loan Portfolio Class (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Average Recorded Investment	$ 2,570	$ 374	$ 1,945	$ 187
Impaired Loans with Allowance: Interest Income	0	0	0	0
Impaired Loans with No Allowance: Average Recorded Investment	8,461	10,231	9,402	10,452
Impaired Loans with No Allowance: Interest Income	80	111	333	343
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Average Recorded Investment	1,360	0	1,152	0
Impaired Loans with Allowance: Interest Income	0	0	0	0
Impaired Loans with No Allowance: Average Recorded Investment	734	1,361	934	1,400
Impaired Loans with No Allowance: Interest Income	0	3	0	3
Commercial real estate
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Average Recorded Investment	832	0	416	0
Impaired Loans with Allowance: Interest Income	0	0	0	0
Impaired Loans with No Allowance: Average Recorded Investment	7,626	8,156	8,155	8,280
Impaired Loans with No Allowance: Interest Income	80	104	293	327
Commercial real estate construction
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Average Recorded Investment	0	0	0	0
Impaired Loans with Allowance: Interest Income	0	0	0	0
Impaired Loans with No Allowance: Average Recorded Investment	0	300	75	337
Impaired Loans with No Allowance: Interest Income	0	0	25	0
Residential mortgage
Financing Receivable, Impaired [Line Items]
Impaired Loans with Allowance: Average Recorded Investment	378	374	377	187
Impaired Loans with Allowance: Interest Income	0	0	0	0
Impaired Loans with No Allowance: Average Recorded Investment	101	414	238	435
Impaired Loans with No Allowance: Interest Income	$ 0	$ 4	$ 15	$ 13

Loans - Schedule of Nonaccrual

Loans - Schedule of Nonaccrual Loans by Classes of the Loan Portfolio (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Purchase credit impaired loans, net of unamortized fair value adjustments	$ 6,900
Total nonaccrual loans	6,695	$ 4,502
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	1,743	2,126
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	4,474	1,593
Commercial real estate construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	0	300
Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	$ 478	$ 483

Loans - Schedule of Troubled De

Loans - Schedule of Troubled Debt Restructurings (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Pre-Modification Outstanding Recorded Investment	$ 8,592	$ 8,928
Post-Modification Outstanding Recorded Investment	8,650	8,986
Recorded Investment at Period End	7,373	7,820
Total nonaccruing troubled debt restructurings
Financing Receivable, Modifications [Line Items]
Pre-Modification Outstanding Recorded Investment	4,015	648
Post-Modification Outstanding Recorded Investment	4,073	648
Recorded Investment at Period End	3,434	377
Total accruing troubled debt restructurings
Financing Receivable, Modifications [Line Items]
Pre-Modification Outstanding Recorded Investment	4,577	8,280
Post-Modification Outstanding Recorded Investment	4,577	8,338
Recorded Investment at Period End	3,939	7,443
Commercial real estate | Total nonaccruing troubled debt restructurings
Financing Receivable, Modifications [Line Items]
Pre-Modification Outstanding Recorded Investment	4,015	648
Post-Modification Outstanding Recorded Investment	4,073	648
Recorded Investment at Period End	3,434	377
Commercial real estate | Total accruing troubled debt restructurings
Financing Receivable, Modifications [Line Items]
Pre-Modification Outstanding Recorded Investment	4,577	7,944
Post-Modification Outstanding Recorded Investment	4,577	8,002
Recorded Investment at Period End	$ 3,939	7,171
Residential mortgage | Total accruing troubled debt restructurings
Financing Receivable, Modifications [Line Items]
Pre-Modification Outstanding Recorded Investment		336
Post-Modification Outstanding Recorded Investment		336
Recorded Investment at Period End		$ 272

Loans - Schedule of Loan Portfo

Loans - Schedule of Loan Portfolio Summarized by the Past Due Status (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 7,658	$ 8,292
Current	1,228,712	899,618
Total Loans Receivable	1,236,370	907,910	$ 872,023
Loans Receivable greater than 90 Days and Accruing	1,626	1,345
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,633	3,558
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	865	1,435
Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,160	3,299
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,826	1,205
Current	167,211	139,139
Total Loans Receivable	169,037	140,344	122,926
Loans Receivable greater than 90 Days and Accruing	6	0
Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	75	26
Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2	1
Commercial and industrial | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,749	1,178
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,313	999
Current	482,360	317,981
Total Loans Receivable	483,673	318,980	309,161
Loans Receivable greater than 90 Days and Accruing	0	0
Commercial real estate | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	325
Commercial real estate | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	674
Commercial real estate | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,313	0
Commercial real estate construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	408	300
Current	39,371	14,971
Total Loans Receivable	39,779	15,271	13,243
Loans Receivable greater than 90 Days and Accruing	0	0
Commercial real estate construction | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	76	0
Commercial real estate construction | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	332	0
Commercial real estate construction | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	300
Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,175	4,936
Current	418,557	343,603
Total Loans Receivable	421,732	348,539	346,422
Loans Receivable greater than 90 Days and Accruing	1,524	937
Residential mortgage | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	695	2,866
Residential mortgage | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	478	657
Residential mortgage | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,002	1,413
Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	856	774
Current	104,257	69,298
Total Loans Receivable	105,113	70,072	65,689
Loans Receivable greater than 90 Days and Accruing	96	408
Home equity lines of credit | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	710	310
Home equity lines of credit | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	50	56
Home equity lines of credit | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	96	408
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	80	78
Current	16,956	14,626
Total Loans Receivable	17,036	14,704	$ 14,582
Loans Receivable greater than 90 Days and Accruing	0	0
Consumer | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	77	31
Consumer | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3	47
Consumer | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	$ 0
Originated Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,526
Current	978,371
Total Loans Receivable	984,897
Loans Receivable greater than 90 Days and Accruing	1,601
Originated Loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	642
Originated Loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	749
Originated Loans | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,135
Originated Loans | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,825
Current	160,832
Total Loans Receivable	162,657
Loans Receivable greater than 90 Days and Accruing	6
Originated Loans | Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	75
Originated Loans | Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1
Originated Loans | Commercial and industrial | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,749
Originated Loans | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,313
Current	339,608
Total Loans Receivable	340,921
Loans Receivable greater than 90 Days and Accruing	0
Originated Loans | Commercial real estate | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Originated Loans | Commercial real estate | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Originated Loans | Commercial real estate | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,313
Originated Loans | Commercial real estate construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	332
Current	31,969
Total Loans Receivable	32,301
Loans Receivable greater than 90 Days and Accruing	0
Originated Loans | Commercial real estate construction | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Originated Loans | Commercial real estate construction | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	332
Originated Loans | Commercial real estate construction | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Originated Loans | Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,737
Current	353,940
Total Loans Receivable	356,677
Loans Receivable greater than 90 Days and Accruing	1,499
Originated Loans | Residential mortgage | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	397
Originated Loans | Residential mortgage | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	363
Originated Loans | Residential mortgage | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,977
Originated Loans | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	251
Current	77,677
Total Loans Receivable	77,928
Loans Receivable greater than 90 Days and Accruing	96
Originated Loans | Home equity lines of credit | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	105
Originated Loans | Home equity lines of credit | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	50
Originated Loans | Home equity lines of credit | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	96
Originated Loans | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	68
Current	14,345
Total Loans Receivable	14,413
Loans Receivable greater than 90 Days and Accruing	0
Originated Loans | Consumer | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	65
Originated Loans | Consumer | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3
Originated Loans | Consumer | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,132
Current	250,341
Total Loans Receivable	251,473
Loans Receivable greater than 90 Days and Accruing	25
Acquired Loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	991
Acquired Loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	116
Acquired Loans | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	25
Acquired Loans | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1
Current	6,379
Total Loans Receivable	6,380
Loans Receivable greater than 90 Days and Accruing	0
Acquired Loans | Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1
Acquired Loans | Commercial and industrial | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Current	142,752
Total Loans Receivable	142,752
Loans Receivable greater than 90 Days and Accruing	0
Acquired Loans | Commercial real estate | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Commercial real estate | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Commercial real estate | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Commercial real estate construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	76
Current	7,402
Total Loans Receivable	7,478
Loans Receivable greater than 90 Days and Accruing	0
Acquired Loans | Commercial real estate construction | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	76
Acquired Loans | Commercial real estate construction | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Commercial real estate construction | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	438
Current	64,617
Total Loans Receivable	65,055
Loans Receivable greater than 90 Days and Accruing	25
Acquired Loans | Residential mortgage | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	298
Acquired Loans | Residential mortgage | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	115
Acquired Loans | Residential mortgage | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	25
Acquired Loans | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	605
Current	26,580
Total Loans Receivable	27,185
Loans Receivable greater than 90 Days and Accruing	0
Acquired Loans | Home equity lines of credit | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	605
Acquired Loans | Home equity lines of credit | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Home equity lines of credit | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12
Current	2,611
Total Loans Receivable	2,623
Loans Receivable greater than 90 Days and Accruing	0
Acquired Loans | Consumer | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12
Acquired Loans | Consumer | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Acquired Loans | Consumer | Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 0

Loans - Schedule of Allowance f

Loans - Schedule of Allowance for Loan Losses and Recorded Investment in Financing Receivables (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Allowance for Loan Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	$ 14,148	$ 14,636	$ 14,194	$ 14,747
Charge-offs	(102)	(165)	(272)	(460)
Recoveries	59	17	183	201
Provisions	0	0	0	0
Allowance for Loan Losses, Ending Balance	14,105	14,488	14,105	14,488
Allowance for Loan Losses, Ending Balance	14,148	14,636	14,194	14,747	$ 14,105	$ 14,194	$ 14,488
Allowance for loan losses: Ending balance: individually evaluated for impairment					1,192	932	167
Allowance for loan losses: Ending balance: collectively evaluated for impairment					12,913	13,262	14,321
Total Loans Receivable					1,236,370	907,910	872,023
Loans receivables: Ending balance: individually evaluated for impairment					10,634	11,945	10,350
Loans Receivable: Ending balance: collectively evaluated for impairment					1,225,736	895,965	861,673
Commercial and Industrial
Allowance for Loan Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	3,246	2,557	3,055	2,508
Charge-offs	(60)	(131)	(129)	(221)
Recoveries	8	5	17	44
Provisions	73	(80)	324	20
Allowance for Loan Losses, Ending Balance	3,267	2,351	3,267	2,351
Allowance for Loan Losses, Ending Balance	3,246	2,557	3,055	2,508	3,267	3,055	2,351
Allowance for loan losses: Ending balance: individually evaluated for impairment					698	599	0
Allowance for loan losses: Ending balance: collectively evaluated for impairment					2,569	2,456	2,351
Total Loans Receivable					169,037	140,344	122,926
Loans receivables: Ending balance: individually evaluated for impairment					1,743	2,126	1,249
Loans Receivable: Ending balance: collectively evaluated for impairment					167,294	138,218	121,677
Commercial Real Estate
Allowance for Loan Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	5,210	5,433	4,968	5,216
Charge-offs	0	0	0	0
Recoveries	0	0	61	0
Provisions	195	(60)	376	157
Allowance for Loan Losses, Ending Balance	5,405	5,373	5,405	5,373
Allowance for Loan Losses, Ending Balance	5,210	5,433	4,968	5,216	5,405	4,968	5,373
Allowance for loan losses: Ending balance: individually evaluated for impairment					117	0	0
Allowance for loan losses: Ending balance: collectively evaluated for impairment					5,288	4,968	5,373
Total Loans Receivable					483,673	318,980	309,161
Loans receivables: Ending balance: individually evaluated for impairment					8,413	8,764	8,042
Loans Receivable: Ending balance: collectively evaluated for impairment					475,260	310,216	301,119
Commercial Real Estate Construction
Allowance for Loan Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	135	134	147	112
Charge-offs	0	0	0	(135)
Recoveries	40	0	40	132
Provisions	(31)	11	(43)	36
Allowance for Loan Losses, Ending Balance	144	145	144	145
Allowance for Loan Losses, Ending Balance	135	134	147	112	144	147	145
Allowance for loan losses: Ending balance: individually evaluated for impairment					0	0	0
Allowance for loan losses: Ending balance: collectively evaluated for impairment					144	147	145
Total Loans Receivable					39,779	15,271	13,243
Loans receivables: Ending balance: individually evaluated for impairment					0	300	300
Loans Receivable: Ending balance: collectively evaluated for impairment					39,779	14,971	12,943
Residential Mortgage
Allowance for Loan Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	3,368	3,311	3,478	3,349
Charge-offs	(15)	(6)	(32)	(45)
Recoveries	10	8	52	14
Provisions	(101)	(46)	(236)	(51)
Allowance for Loan Losses, Ending Balance	3,262	3,267	3,262	3,267
Allowance for Loan Losses, Ending Balance	3,368	3,311	3,478	3,349	3,262	3,478	3,267
Allowance for loan losses: Ending balance: individually evaluated for impairment					377	333	167
Allowance for loan losses: Ending balance: collectively evaluated for impairment					2,885	3,145	3,100
Total Loans Receivable					421,732	348,539	346,422
Loans receivables: Ending balance: individually evaluated for impairment					478	755	759
Loans Receivable: Ending balance: collectively evaluated for impairment					421,254	347,784	345,663
Home Equity Lines of Credit
Allowance for Loan Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	607	607	648	619
Charge-offs	(9)	0	(9)	(9)
Recoveries	0	0	0	0
Provisions	29	2	(12)	(1)
Allowance for Loan Losses, Ending Balance	627	609	627	609
Allowance for Loan Losses, Ending Balance	607	607	648	619	627	648	609
Allowance for loan losses: Ending balance: individually evaluated for impairment					0	0	0
Allowance for loan losses: Ending balance: collectively evaluated for impairment					627	648	609
Total Loans Receivable					105,113	70,072	65,689
Loans receivables: Ending balance: individually evaluated for impairment					0	0	0
Loans Receivable: Ending balance: collectively evaluated for impairment					105,113	70,072	65,689
Consumer
Allowance for Loan Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	815	952	923	1,083
Charge-offs	(18)	(28)	(102)	(50)
Recoveries	1	4	13	11
Provisions	12	(11)	(24)	(127)
Allowance for Loan Losses, Ending Balance	810	917	810	917
Allowance for Loan Losses, Ending Balance	815	952	923	1,083	810	923	917
Allowance for loan losses: Ending balance: individually evaluated for impairment					0	0	0
Allowance for loan losses: Ending balance: collectively evaluated for impairment					810	923	917
Total Loans Receivable					17,036	14,704	14,582
Loans receivables: Ending balance: individually evaluated for impairment					0	0	0
Loans Receivable: Ending balance: collectively evaluated for impairment					17,036	14,704	14,582
Unallocated
Allowance for Loan Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	767	1,642	975	1,860
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provisions	(177)	184	(385)	(34)
Allowance for Loan Losses, Ending Balance	590	1,826	590	1,826
Allowance for Loan Losses, Ending Balance	$ 767	$ 1,642	$ 975	$ 1,860	590	975	1,826
Allowance for loan losses: Ending balance: individually evaluated for impairment					0	0	0
Allowance for loan losses: Ending balance: collectively evaluated for impairment					590	975	1,826
Total Loans Receivable					0	0	0
Loans receivables: Ending balance: individually evaluated for impairment					0	0	0
Loans Receivable: Ending balance: collectively evaluated for impairment					$ 0	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$ 158,392	$ 142,990	$ 143,940
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	1,799	1,716
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	156,593	141,274
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Impaired loans | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Impaired loans | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Impaired loans | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	5,462	4,406
U.S. Government and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	99,014	79,579
Mortgage-backed securities, residential
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	37,351	31,973
State and municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	15,116	24,660
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	5,112	5,062
CRA mutual fund
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	1,042	1,035
Stock in other banks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	757	681
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	1,799	1,716
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	156,593	141,274
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | U.S. Government and agencies | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | U.S. Government and agencies | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	99,014	79,579
Recurring | U.S. Government and agencies | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | Mortgage-backed securities, residential | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | Mortgage-backed securities, residential | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	37,351	31,973
Recurring | Mortgage-backed securities, residential | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | State and municipal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | State and municipal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	15,116	24,660
Recurring | State and municipal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | Corporate bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | Corporate bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	5,112	5,062
Recurring | Corporate bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | CRA mutual fund | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	1,042	1,035
Recurring | CRA mutual fund | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | CRA mutual fund | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | Stock in other banks | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	757	681
Recurring | Stock in other banks | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Recurring | Stock in other banks | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	0	0
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	158,392	142,990
Fair Value | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	5,462	4,406
Fair Value | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	158,392	142,990
Fair Value | Recurring | U.S. Government and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	99,014	79,579
Fair Value | Recurring | Mortgage-backed securities, residential
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	37,351	31,973
Fair Value | Recurring | State and municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	15,116	24,660
Fair Value | Recurring | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	5,112	5,062
Fair Value | Recurring | CRA mutual fund
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	1,042	1,035
Fair Value | Recurring | Stock in other banks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$ 757	$ 681

Fair Value Measurements - Sch60

Fair Value Measurements - Schedule of Additional Quantitative Information (Details) - Impaired loans - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average	(34.00%)	(39.00%)
Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average	(10.00%)	(10.00%)
Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted Average	(50.00%)	(50.00%)
Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate	$ 5,462	$ 4,406

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Period for order of valuations (at least)	18 months

Fair Value Measurements - Sch62

Fair Value Measurements - Schedule of Carrying Amount, Fair Value and Placement in Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Financial assets:
Interest-bearing deposits in banks	$ 31,609	$ 5,135	$ 41,686
Total securities available for sale	158,392	142,990	143,940
Investment securities held to maturity	47,373	55,425	58,566
Restricted investment in bank stocks	4,821	4,349	$ 4,191
Level 1
Financial assets:
Cash and due from banks	8,131	6,921
Interest-bearing deposits in banks	31,609	5,135
Total securities available for sale	1,799	1,716
Investment securities held to maturity	0	0
Loans held for sale	0	0
Loans, less allowance for loan losses	0	0
Accrued interest receivable	0	0
Restricted investment in bank stocks	0	0
Financial liabilities:
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Accrued interest payable	0	0
Off-balance sheet financial instruments	0	0
Level 2
Financial assets:
Cash and due from banks	9,751	6,875
Interest-bearing deposits in banks	0	0
Total securities available for sale	156,593	141,274
Investment securities held to maturity	47,373	55,425
Loans held for sale	1,873	1,770
Loans, less allowance for loan losses	0	0
Accrued interest receivable	3,795	3,158
Restricted investment in bank stocks	4,821	4,349
Financial liabilities:
Deposits	1,307,677	967,236
Short-term borrowings	33,806	34,590
Long-term borrowings	97,129	75,029
Accrued interest payable	1,072	837
Off-balance sheet financial instruments	0	0
Level 3
Financial assets:
Cash and due from banks	0	0
Interest-bearing deposits in banks	0	0
Total securities available for sale	0	0
Investment securities held to maturity	0	0
Loans held for sale	0	0
Loans, less allowance for loan losses	1,205,807	888,169
Accrued interest receivable	0	0
Restricted investment in bank stocks	0	0
Financial liabilities:
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Accrued interest payable	0	0
Off-balance sheet financial instruments	0	0
Carrying Amount
Financial assets:
Cash and due from banks	17,882	13,796
Interest-bearing deposits in banks	31,609	5,135
Total securities available for sale	158,392	142,990
Investment securities held to maturity	47,369	55,568
Loans held for sale	1,873	1,770
Loans, less allowance for loan losses	1,222,265	893,176
Accrued interest receivable	3,795	3,158
Restricted investment in bank stocks	4,821	4,349
Financial liabilities:
Deposits	1,311,884	967,621
Short-term borrowings	33,806	34,590
Long-term borrowings	96,850	74,250
Accrued interest payable	1,072	837
Off-balance sheet financial instruments	0	0
Fair Value
Financial assets:
Cash and due from banks	17,882	13,796
Interest-bearing deposits in banks	31,609	5,135
Total securities available for sale	158,392	142,990
Investment securities held to maturity	47,373	55,425
Loans held for sale	1,873	1,770
Loans, less allowance for loan losses	1,205,807	888,169
Accrued interest receivable	3,795	3,158
Restricted investment in bank stocks	4,821	4,349
Financial liabilities:
Deposits	1,307,677	967,236
Short-term borrowings	33,806	34,590
Long-term borrowings	97,129	75,029
Accrued interest payable	1,072	837
Off-balance sheet financial instruments	$ 0	$ 0

Securities Sold Under Agreeme63

Securities Sold Under Agreements to Repurchase (Repurchase Agreements) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Gross Amounts of Recognized Liabilities	$ 33,806	$ 34,590
Gross Amounts Offset in the Statements of Condition	0	0
Net Amounts of Liabilities Presented in the Statements of Condition	33,806	34,590
Financial Instruments	(33,806)	(34,590)
Cash Collateral Pledged	0	0
Net Amount	0	0
Fair value of securities pledged in connection with repurchase agreements	41,149	$ 41,406
Total	33,806
U.S. Treasury and agency securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	33,806
Overnight and Continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	33,806
Overnight and Continuous | U.S. Treasury and agency securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	33,806
Up to 30 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	0
Up to 30 Days | U.S. Treasury and agency securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	0
30 - 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	0
30 - 90 Days | U.S. Treasury and agency securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	0
Greater than 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	0
Greater than 90 Days | U.S. Treasury and agency securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	$ 0

Borrowings (Details)

Borrowings (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Debt Instrument [Line Items]
Long-term debt outstanding	$ 96,850,000	$ 74,250,000	$ 76,500,000
FHLB Advances
Debt Instrument [Line Items]
Long-term debt outstanding	$ 87,250,000	74,250,000
Weighted average rate percentage	1.80%
Loan payable to local bank
Debt Instrument [Line Items]
Long-term debt outstanding	$ 4,600,000	0
Loan payable to local bank draw period	1 year
Fixed rate percentage	4.50%
Period of fixed interest rate	5 years
Trust preferred subordinated debt
Debt Instrument [Line Items]
Long-term debt outstanding	$ 5,000,000	$ 0
Fixed rate percentage	6.39%
Trust preferred subordinated debt issued	$ 5,000,000

Goodwill and Other Intangible65

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	Jul. 01, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Finite-Lived Intangible Assets [Line Items]
Goodwill		$ 19,580	$ 6,308	$ 6,308
Customer lists
Finite-Lived Intangible Assets [Line Items]
Amortization period		10 years
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Amortization period		10 years
RIG
Finite-Lived Intangible Assets [Line Items]
Goodwill		$ 6,308
RIG | Customer lists
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount of intangible asset		6,667
Accumulated amortization of intangible asset		$ 6,223
Amortization period		10 years
New Windsor
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 13,272	$ 13,272
New Windsor | Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount of intangible asset		2,418
Accumulated amortization of intangible asset		$ 110
Amortization period	10 years	10 years
Minimum | Customer lists
Finite-Lived Intangible Assets [Line Items]
Amortization period		8 years
Maximum | Customer lists
Finite-Lived Intangible Assets [Line Items]
Amortization period		13 years