Mid Penn Bancorp (MPB) 10-K 13 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 01, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,017
Trading Symbol	MPB
Entity Registrant Name	MID PENN BANCORP INC
Entity Central Index Key	879,635
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		6,121,043
Entity Current Reporting Status	Yes
Entity Public Float			$ 114,351,399
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks	$ 19,795,000	$ 13,493,000
Interest-bearing balances with other financial institutions	3,028,000	2,003,000
Federal funds sold	691,000	30,477,000
Total cash and cash equivalents	23,514,000	45,973,000
Investment securities available for sale	93,465,000	133,625,000
Investment securities held to maturity, at amortized cost (fair value $100,483 and $0)	101,356,000	0
Loans held for sale	1,040,000	1,959,000
Loans and leases, net of unearned interest	910,404,000	813,924,000
Less: Allowance for loan and lease losses	(7,606,000)	(7,183,000)
Net loans and leases	902,798,000	806,741,000
Bank premises and equipment, net	16,168,000	11,074,000
Bank premises and equipment held for sale	0	1,894,000
Cash surrender value of life insurance	13,042,000	12,780,000
Restricted investment in bank stocks	4,384,000	2,443,000
Foreclosed assets held for sale	189,000	224,000
Accrued interest receivable	4,564,000	3,928,000
Deferred income taxes	1,888,000	4,286,000
Goodwill	3,918,000	3,918,000
Core deposit and other intangibles, net	434,000	539,000
Other assets	3,594,000	3,215,000
Total Assets	1,170,354,000	1,032,599,000
LIABILITIES & SHAREHOLDERS’ EQUITY
Deposits: Noninterest-bearing demand	163,714,000	122,811,000
Deposits: Interest-bearing demand	349,241,000	317,533,000
Deposits: Money Market	246,220,000	252,271,000
Deposits: Savings	62,770,000	60,163,000
Deposits: Time	201,623,000	182,595,000
Total Deposits	1,023,568,000	935,373,000
Short-term borrowings	34,611,000
Long-term debt	12,352,000	13,581,000
Subordinated debt	17,338,000	7,414,000
Accrued interest payable	645,000	515,000
Other liabilities	6,137,000	5,249,000
Total Liabilities	1,094,651,000	962,132,000
Shareholders' Equity:
Common stock, par value $1.00; authorized 10,000,000 shares; 4,242,216 and 4,233,297 shares issued and outstanding at December 31, 2017 and December 31, 2016, respectively	4,242,000	4,233,000
Additional paid-in capital	40,970,000	40,688,000
Retained earnings	32,565,000	28,399,000
Accumulated other comprehensive loss	(2,074,000)	(2,853,000)
Total Shareholders’ Equity	75,703,000	70,467,000
Total Liabilities and Shareholders' Equity	$ 1,170,354,000	$ 1,032,599,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Investment securities held-to-maturity, fair value	$ 100,483	$ 0
Common Stock, Par Value	$ 1	$ 1
Common Stock, Shares Authorized	10,000,000	10,000,000
Common Stock, Shares, Issued	4,242,216	4,233,297
Common Stock, Shares, Outstanding	4,242,216	4,233,297

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INTEREST INCOME
Interest and fees on loans and leases	$ 40,156	$ 36,402	$ 32,840
Interest on interest-bearing balances	18	12	44
Interest and dividends on investment securities:
U.S. Treasury and government agencies	2,273	1,346	1,222
State and political subdivision obligations, tax-exempt	1,113	2,066	2,000
Other securities	217	304	382
Interest on federal funds sold	115	82	2
Total Interest Income	43,892	40,212	36,490
INTEREST EXPENSE
Interest on deposits	5,463	4,514	3,889
Interest on short-term borrowings	111	15	47
Interest on long-term and subordinated debt	730	838	671
Total Interest Expense	6,304	5,367	4,607
Net Interest Income	37,588	34,845	31,883
PROVISION FOR LOAN AND LEASE LOSSES	325	1,870	1,065
Net Interest Income After Provision for Loan and Lease Losses	37,263	32,975	30,818
NONINTEREST INCOME
Income from fiduciary activities	845	481	466
Service charges on deposits	721	684	690
Net gain on sales of investment securities	42	1,046	325
Earnings from cash surrender value of life insurance	262	264	269
Mortgage banking income	872	922	456
ATM debit card interchange income	937	844	741
Merchant services income	335	317	235
Net gain on sales of SBA loans	800	470	252
Other income	879	896	679
Total Noninterest Income	5,693	5,924	4,113
NONINTEREST EXPENSE
Salaries and employee benefits	16,929	15,564	14,043
Occupancy expense, net	2,512	2,064	1,947
Equipment expense	1,536	1,689	1,477
Pennsylvania Bank Shares Tax expense	451	648	408
FDIC Assessment	792	688	613
Legal and professional fees	802	711	588
Marketing and advertising expense	516	500	533
Software licensing	1,458	1,380	1,472
Telephone expense	497	548	569
Loss on sale or write-down of foreclosed assets	88	217	111
Intangible amortization	104	126	114
Merger and acquisition expense	619		762
Other expenses	5,063	4,683	4,122
Total Noninterest Expense	31,367	28,818	26,759
INCOME BEFORE PROVISION FOR INCOME TAXES	11,589	10,081	8,172
Provision for income taxes	4,500	2,277	1,644
NET INCOME	7,089	7,804	6,528
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS	$ 7,089	$ 7,804	$ 6,038
PER COMMON SHARE DATA:
Basic and Diluted Earnings Per Common Share	$ 1.67	$ 1.85	$ 1.47
Cash Dividends Declared	$ 0.77	$ 0.68	$ 0.44
Series B Preferred Stock [Member]
NONINTEREST EXPENSE
Preferred stock dividends and redemption premium			$ 473
Preferred stock dividends			373
Series C Preferred Stock [Member]
NONINTEREST EXPENSE
Preferred stock dividends			$ 17

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 7,089	$ 7,804	$ 6,528
Other comprehensive income (loss):
Unrealized gains (losses) arising during the period on available for sale securities, net of income taxes of $589, ($1,954), and $80, respectively		1,143	(3,794)	154
Reclassification adjustment for net gain on sales of available for sale securities included in net income, net of income taxes of ($14), ($356), and ($110), respectively (a)	[1]	(28)	(690)	(215)
Change in defined benefit plans, net of income taxes of $3, ($93), and $185, respectively (b)	[2]	5	(181)	360
Total other comprehensive income (loss)		1,120	(4,665)	299
Total comprehensive income		$ 8,209	$ 3,139	$ 6,827
[1]	Amounts are included in net gain on sales of investment securities on the Consolidated Statements of Income as a separate component within total noninterest income
[2]	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 as a separate element within total noninterest expense

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Unrealized gains (losses) arising during the period on available for sale securities, tax	$ 589	$ (1,954)	$ 80
Reclassification adjustment for net gain on sales of available for sale securities included in net income, tax	(14)	(356)	(110)
Change in defined benefit plans, tax	$ 3	$ (93)	$ 185

Consolidated Statements of Chan

Consolidated Statements of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Series B Preferred Stock [Member]	Series C Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock [Member]Series B Preferred Stock [Member]	Preferred Stock [Member]Series C Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Series B Preferred Stock [Member]	Retained Earnings [Member]Series C Preferred Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2014	$ 59,130			$ 5,000			$ 3,498	$ 29,902	$ 19,217			$ 1,513
Net income	6,528								6,528
Total other comprehensive (loss) income, net of taxes	299											299
Common stock dividends	(1,785)								(1,785)
Employee Stock Purchase Plan	66						4	62
Preferred stock dividends		$ (373)	$ (17)							$ (373)	$ (17)
Preferred stock redemption		(5,000)	(1,750)		$ (5,000)	$ (1,750)
Preferred stock redemption premium		$ (100)								$ (100)
Preferred stock issuance			$ 1,750			$ 1,750
Common stock issued to Phoenix shareholders	11,292						724	10,568
Restricted stock activity	28						1	27
Balance at Dec. 31, 2015	70,068						4,227	40,559	23,470			1,812
Net income	7,804								7,804
Total other comprehensive (loss) income, net of taxes	(4,665)											(4,665)
Common stock dividends	(2,875)								(2,875)
Employee Stock Purchase Plan	82						4	78
Restricted stock activity	53						2	51
Balance at Dec. 31, 2016	70,467						4,233	40,688	28,399			(2,853)
Net income	7,089								7,089
Total other comprehensive (loss) income, net of taxes	1,120											1,120
Common stock dividends	(3,264)								(3,264)
Employee Stock Purchase Plan	104						4	100
Director Stock Purchase Plan	42						1	41
Restricted stock activity	145						4	141
Tax rate adjustment impact									341			(341)
Balance at Dec. 31, 2017	$ 75,703			$ 0			$ 4,242	$ 40,970	$ 32,565			$ (2,074)

Consolidated Statements of Cha8

Consolidated Statements of Changes In Shareholders' Equity (Parenthetical) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Stockholders Equity [Abstract]
Stock issued during period, shares, Employee Stock Purchase Plans	3,578	4,465	4,162
Stock issued during period shares, Director Stock Purchase Plans	1,345
Stock issued during period, shares, acquisitions			723,851
Stock issued during period, shares, Restricted stock activity	3,996	2,115	875

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities:
Net Income	$ 7,089,000	$ 7,804,000	$ 6,528,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	325,000	1,870,000	1,065,000
Depreciation	1,464,000	1,658,000	1,485,000
Amortization of intangibles	105,000	126,000	100,000
Net amortization of security premiums	1,280,000	11,709,000	4,251,000
Gain on sales of investment securities	(42,000)	(1,046,000)	(325,000)
Earnings on cash surrender value of life insurance	(262,000)	(264,000)	(269,000)
Mortgage loans originated for sale	(44,010,000)	(42,888,000)	(26,083,000)
Proceeds from sales of mortgage loans originated for sale	45,801,000	43,810,000	26,539,000
Gain on sale of mortgage loans	(872,000)	(922,000)	(456,000)
SBA loans originated for sale	(10,282,000)	(5,872,000)	(3,484,000)
Proceeds from sales of SBA loans originated for sale	11,082,000	6,342,000	3,736,000
Gain on sale of SBA loans	(800,000)	(470,000)	(252,000)
Loss on write-down/disposal of property, plant, and equipment	14,000	142,000
Loss on sale / write-down of foreclosed assets	88,000	217,000	111,000
Restricted stock compensation expense	145,000	53,000	27,000
Deferred income tax expense (benefit)	1,828,000	(336,000)	997,000
Increase in accrued interest receivable	(636,000)	(115,000)	(367,000)
(Increase) decrease in other assets	(380,000)	(99,000)	333,000
Increase in accrued interest payable	130,000	125,000	9,000
(Decrease) increase in other liabilities	(172,000)	4,000	(771,000)
Net Cash Provided By Operating Activities	11,895,000	21,848,000	13,174,000
Investing Activities:
Net decrease in interest-bearing time deposits with other financial institutions		4,317,000	1,455,000
Proceeds from the maturity of investment securities	11,062,000	16,110,000	11,940,000
Proceeds from the sale of investment securities	52,932,000	111,390,000	37,142,000
Purchases of investment securities	(124,738,000)	(142,861,000)	(35,858,000)
Net cash received from acquisition			8,095,000
(Purchases) redemptions of restricted investment in bank stocks	(1,941,000)	1,823,000	(576,000)
Net increase in loans and leases	(96,570,000)	(77,795,000)	(60,043,000)
Purchases of bank premises and equipment	(6,879,000)	(775,000)	(1,461,000)
Proceeds from sale of bank premises and equipment	2,201,000
Proceeds from sale of foreclosed assets	136,000	992,000	403,000
Net Cash Used In Investing Activities	(163,797,000)	(86,799,000)	(38,903,000)
Financing Activities:
Net increase in deposits	88,195,000	158,330,000	15,883,000
Net increase (decrease) in short-term borrowings	34,611,000	(31,596,000)	31,018,000
Common stock dividends paid	(2,204,000)	(2,452,000)	(1,785,000)
Long-term debt repayment	(1,220,000)	(26,724,000)	(16,226,000)
Deferred financing fees paid for subordinated debt issuance	(85,000)		(85,000)
Subordinated debt issuance	10,000,000		7,500,000
Net Cash Provided By Financing Activities	129,443,000	97,640,000	29,131,000
Net (decrease) increase in cash and cash equivalents	(22,459,000)	32,689,000	3,402,000
Cash and cash equivalents, beginning of year	45,973,000	13,284,000	9,882,000
Cash and cash equivalents, end of year	23,514,000	45,973,000	13,284,000
Supplemental Disclosures of Cash Flow Information:
Interest paid	6,174,000	5,242,000	4,566,000
Income taxes paid	3,890,000	1,700,000	1,130,000
Supplemental Noncash Disclosures:
Loan transfers to foreclosed assets held for sale	189,000	248,000	1,135,000
Asset transfers to bank premises and equipment held for sale		1,894,000
Phoenix Bancorp Inc. [Member]
Supplemental Noncash Disclosures:
Common stock issued to Phoenix shareholders			11,292,000
Assets Acquired:
Securities			11,331,000
Loans			110,363,000
Restricted stock			509,000
Property and equipment			1,792,000
Deferred income taxes			503,000
Accrued interest receivable			388,000
Core deposit and other intangible assets			578,000
Bank-owned life insurance			3,673,000
Other assets			624,000
Assets acquired			129,761,000
Liabilities Assumed:
Deposits			123,238,000
Accrued interest payable			32,000
Long-term debt			3,570,000
Other liabilities			876,000
Liabilities assumed			127,716,000
Equity Acquired:
Preferred stock			1,750,000
Employee [Member]
Financing Activities:
Stock Purchase Plan share issuance	104,000	$ 82,000	66,000
Director [Member]
Financing Activities:
Stock Purchase Plan share issuance	$ 42,000
Series B Preferred Stock [Member]
Financing Activities:
Preferred stock dividends and redemption premium paid			(473,000)
Preferred stock redemption			(5,000,000)
Series C Preferred Stock [Member]
Financing Activities:
Preferred stock redemption			(1,750,000)
Preferred stock dividends paid			$ (17,000)

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	(1) Basis of Presentation The accompanying consolidated financial statements include the accounts of Mid Penn Bancorp, Inc. and its wholly-owned subsidiary Mid Penn Bank (the “Bank”), and the Bank’s former wholly-owned subsidiary Mid Penn Insurance Services, LLC, which was closed, effective March 1, 2016 (collectively, “Mid Penn”). All material intercompany accounts and transactions have been eliminated in consolidation. Each of Mid Penn’s lines of business are part of the same reporting segment, community banking, whose operating results are regularly reviewed and managed by a centralized executive management group. As a result, Mid Penn has only one reportable segment for financial reporting purposes. The comparability of the results of operations for the year ended 2017 compared to 2016 and 2015, in general, have been impacted by the acquisition activities of Mid Penn as further described in Note 4. For comparative purposes, the 2016 and 2015 balances have been reclassified to conform to the 2017 presentation. Such reclassifications had no impact on net income.

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	(2) Nature of Business Mid Penn, through operations conducted by the Bank, engages in a full-service commercial banking and trust business, making available to the community a wide range of financial services, including, but not limited to, mortgage and home equity loans, secured and unsecured commercial and consumer loans, lines of credit, construction financing, farm loans, community development loans, loans to non-profit entities and local government loans and various types of time and demand deposits, including but not limited to, checking accounts, savings accounts, clubs, money market deposit accounts, certificates of deposit, and IRAs. In addition, the Bank provides a full range of trust services through its Trust Department. Deposits are insured by the Federal Deposit Insurance Corporation (“FDIC”) to the extent provided by law. The financial services are provided to individuals, partnerships, non-profit organizations, and corporations through its 23 retail banking offices located in Cumberland, Dauphin, Lancaster, Luzerne, Northumberland, and Schuylkill Counties. A former subsidiary of the Bank, Mid Penn Insurance Services, LLC, was closed effective March 1, 2016 due to a lack of activity within the subsidiary. Mid Penn Insurance Services, LLC was an immaterial subsidiary of the Bank, and was immaterial to Mid Penn’s consolidated results.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	(3) Summary of Significant Accounting Policies The accounting and reporting policies of Mid Penn conform with accounting principles generally accepted in the United States of America (“GAAP”) and to general practice within the financial industry. The following is a description of the more significant accounting policies. (a) Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan and lease losses, the assessment of other-than-temporary impairment of investment securities, the valuation of the goodwill for impairment, and the valuation of assets acquired and liabilities assumed in business combinations. (b) Cash and Cash Equivalents For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash on hand, balances due from banks, and federal funds sold, all of which mature within ninety days. (c) Interest-bearing Time Deposits with Other Financial Institutions Interest-bearing time deposits with other financial institutions consist of certificates of deposits in other financial institutions with maturities within one year. (d) Investment Securities Available-for-sale securities include debt and equity securities which are reported at fair value, with unrealized holding gains and losses excluded from earnings being reported, net of deferred income taxes, as a component of accumulated other comprehensive income (loss) within shareholders’ equity. During 2017, Mid Penn added a held-to-maturity pool to its overall investment portfolio of debt securities, which are reported at amortized cost. Unrealized holding gains and losses on held-to-maturity securities are excluded from earnings, and are not a component of accumulated other comprehensive income (loss) within shareholders’ equity. As of December 31, 2017, Mid Penn had $101,356,000 of held-to-maturity securities recorded at amortized cost. Mid Penn had no held-to-maturity securities in 2016 and 2015. Premiums and discounts on debt securities are amortized as an adjustment to interest income using the interest method. Realized gains and losses on sales of investment securities are computed on the basis of specific identification of the cost of each security. Net gains on sales of investment securities were $42,000 in 2017, $1,046,000 in 2016, and $325,000 in 2015. (e) Loans Held for Sale Mortgage loans originated and intended for sale in the secondary market are included in loans held for sale and are carried at fair value, as determined by outstanding commitments from investors. Gains and losses on sales of mortgage loans are included in the Consolidated Statements of Income in mortgage banking income. Mortgage banking income was $872,000 in 2017, $922,000 in 2016, and $456,000 in 2015. (f) Loans and Allowance for Loan and Lease Losses Loans receivable that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are stated at their outstanding unpaid principal balances, net of an allowance for loan losses and any deferred fees or costs. Interest income is accrued on the unpaid principal balance. Residential loans held for sale are carried at fair value and are included in loans held for sale on the balance sheet. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the yield (interest income) of the related loans. These amounts are generally being amortized over the contractual life of the loan. Premiums and discounts on purchased loans are amortized as adjustments to interest income using the effective yield method. The loan portfolio is segmented into commercial and consumer loans. Commercial loans consist of the following classes: commercial and industrial, commercial real estate, commercial real estate-construction and lease financing. Consumer loans consist of the following classes: residential mortgage loans, home equity loans and other consumer loans. For all classes of loans, the accrual of interest is discontinued when the contractual payment of principal or interest has become 90 days or more past due or management has serious doubts about further collectability of principal or interest, even though the loan is currently performing. A loan may remain on accrual status if it is in the process of collection and is either guaranteed or well secured. When a loan is placed on nonaccrual status, unpaid interest is credited to income. Interest received on nonaccrual loans, including impaired loans, generally is either applied against principal or reported as interest income, according to management’s judgment as to the collectability of principal. Generally, loans are restored to accrual status when the obligation is brought current, has performed in accordance with the contractual terms for a reasonable period of time (generally six months) and the ultimate collectability of the total contractual principal and interest is no longer in doubt. The past due status of all classes of loans receivable is determined based on contractual due dates for loan payments. Commercial and industrial Mid Penn originates commercial and industrial loans. Most of the Bank’s commercial and industrial loans have been extended to finance local and regional businesses and include short-term loans to finance machinery and equipment purchases, inventory, and accounts receivable. Commercial loans also involve the extension of revolving credit for a combination of equipment acquisitions and working capital in expanding companies. The maximum term for loans extended on machinery and equipment is based on the projected useful life of such machinery and equipment. Generally, the maximum term on non-mortgage lines of credit is one year. The loan-to-value ratio on such loans and lines of credit generally may not exceed 80% of the value of the collateral securing the loan. The Bank’s commercial business lending policy includes credit file documentation and analysis of the borrower’s character, capacity to repay the loan, the adequacy of the borrower’s capital and collateral, as well as an evaluation of conditions affecting the borrower. Analysis of the borrower’s past, present, and future cash flows is also an important aspect of the Bank’s current credit analysis. Nonetheless, such loans are believed to carry higher credit risk than other extensions of credit. Commercial and industrial loans typically are made on the basis of the borrower’s ability to make repayment from the cash flow of the borrower’s business. As a result, the availability of funds for the repayment of commercial business loans may be substantially dependent on the success of the business itself, which, in turn, is likely to be dependent upon the general economic environment. Mid Penn’s commercial and industrial loans are usually, but not always, secured by business assets and personal guarantees. However, the collateral securing the loans may depreciate over time, may be difficult to appraise, and may fluctuate in value based on the success of the business. Commercial real estate and commercial real estate - construction Commercial real estate and commercial real estate construction loans generally present a higher level of risk than loans secured by one to four family residences. This greater risk is due to several factors, including the concentration of principal in a limited number of loans and borrowers, the effect of general economic conditions on income producing properties, and the increased difficulty of evaluating and monitoring these types of loans. In addition, the repayment of loans secured by commercial real estate is typically dependent upon the successful operation of the related real estate project. If the cash flow from the project is reduced, the borrower’s ability to repay the loan may be impaired. Residential mortgage Mid Penn offers a wide array of residential mortgage loans for both permanent structures and those under construction. The Bank’s residential mortgage originations are secured primarily by properties located in its primary market and surrounding areas. Residential mortgage loans have terms up to a maximum of 30 years and with loan to value ratios up to 100% of the lesser of the appraised value of the security property or the contract price. Private mortgage insurance is generally required in an amount sufficient to reduce the Bank’s exposure to at or below the 85% loan to value level. Residential mortgage loans generally do not include prepayment penalties. In underwriting residential mortgage loans, the Bank evaluates both the borrower’s ability to make monthly payments and the value of the property securing the loan. Most properties securing real estate loans made by Mid Penn are appraised by independent fee appraisers. The Bank generally requires borrowers to obtain title insurance and fire and property insurance (including flood insurance, if necessary) in an amount not less than the amount of the loan. Real estate loans originated by the Bank generally contain a “due on sale” clause allowing the Bank to declare the unpaid principal balance due and payable upon the sale of the security property. The Bank underwrites residential mortgage loans to the standards established by the secondary mortgage market, i.e., Fannie Mae, Ginnie Mae, Freddie Mac, or Pennsylvania Housing Finance Agency standards, with the intention of selling the majority of residential mortgages originated into the secondary market. In the event that the facts and circumstances surrounding a residential mortgage application do not meet all underwriting conditions of the secondary mortgage market, the Bank will evaluate the failed conditions and evaluate the potential risk of holding the residential mortgage in the Bank’s portfolio rather than rejecting the loan request. In the event that the loan is held in the Bank’s portfolio, the interest rate on the residential mortgage typically would be increased to compensate for the added portfolio risk. Consumer, including home equity Mid Penn offers a variety of secured consumer loans, including home equity, automobile, and deposit secured loans. In addition, the Bank offers other secured and unsecured consumer loans. Most consumer loans are originated in Mid Penn’s primary market and surrounding areas. The largest component of Mid Penn’s consumer loan portfolio consists of fixed rate home equity loans and variable rate home equity lines of credit. Substantially all home equity loans and lines of credit are secured by second mortgages on principal residences. The Bank will lend amounts, which, together with all prior liens, typically may be up to 85% of the appraised value of the property securing the loan. Home equity term loans may have maximum terms up to 20 years while home equity lines of credit generally have maximum terms of five years. Consumer loan terms vary according to the type and value of collateral, length of contract and creditworthiness of the borrower. The underwriting standards employed by the Bank for consumer loans include an application, a determination of the applicant’s payment history on other debts, and an assessment of ability to meet existing obligations and payments on the proposed loan. Although creditworthiness of the applicant is a primary consideration, the underwriting process also includes a comparison of the value of the collateral, if any, in relation to the proposed loan amount. Consumer loans may entail greater credit risk than do residential mortgage loans, 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. 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 that can be recovered on such loans. 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 weakens and property values deteriorate. Allowance for Loan and Lease Losses The allowance for credit losses consists of the allowance for loan and lease losses and the reserve for unfunded lending commitments. The allowance for loan and lease losses represents management’s estimate of losses inherent in the loan portfolio as of the balance sheet date and is recorded as a reduction to loans. Mid Penn also estimates a reserve for unfunded lending commitments, which represents management’s estimate of losses inherent in its unfunded loan commitments and is recorded in other liabilities on the consolidated balance sheet. The reserve for unfunded loan commitments was $105,000 at December 31, 2017 and $120,000 at December 31, 2016. The allowance for loan and lease losses is increased by the provision for loan and lease losses, and decreased by charge-offs, net of recoveries. Loans deemed to be uncollectible are charged against the allowance for loan and lease losses, and subsequent recoveries, if any, are credited to the allowance. All, or part, of the principal balance of loans are charged off to the allowance as soon as it is determined that the repayment of all, or part, of the principal balance is highly unlikely. Non-residential consumer loans are generally charged off no later than 120 days past due on a contractual basis, earlier in the event of bankruptcy, or if there is an amount deemed uncollectible. Because all identified losses are immediately charged off, no portion of the allowance for loan and lease losses is restricted to any individual loan or groups of loans, and the entire allowance is available to absorb any and all loan losses. The allowance for credit losses is maintained at a level considered adequate to provide for losses that can be reasonably anticipated. Management performs a monthly evaluation of the adequacy of the allowance. The allowance is based on Mid Penn’s past loan loss experience, known and inherent risks in the portfolio, adverse situations that may affect the borrower’s ability to repay, the estimated value of any underlying collateral, composition of the loan portfolio, current economic conditions, and other relevant factors. This evaluation is inherently subjective as it requires material estimates that may be 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 impaired. For loans that are classified as impaired, an allowance is established when the discounted cash flows (“DCF”), 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 each of these categories of loans, adjusted for qualitative factors. These qualitative risk factors include changes in economic conditions, fluctuations in loan quality measures, changes in collateral values, changes in the experience of the lending staff and loan review systems, changes in lending policies and procedures, including underwriting standards, changes in the mix and volume of loans originated, the effect of other external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in the existing loan portfolio, and shifting industry or portfolio 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. Mid Penn generally considers a commercial loan (consisting of commercial and industrial, commercial real estate, commercial real estate-construction, and lease financing loan classes) to be impaired when it becomes 90 days or more past due and not in the process of collection or sooner when it is probable that Mid Penn will be unable to collect all contractual principal and interest due. This methodology assumes the borrower cannot or will not continue to make additional payments. At that time the loan would generally be considered collateral dependent as the DCF method would generally indicate no operating income available for evaluating the collateral position; therefore, most impaired loans are deemed to be collateral dependent. In addition, Mid Penn’s rating system assumes any loans classified as nonaccrual, included in the substandard rating, to be impaired, and most of these loans are considered collateral dependent; therefore, most of Mid Penn’s impaired loans, whether reporting a specific allocation or not, are considered collateral dependent. Mid Penn evaluates loans for charge-off on a monthly basis. Policies that govern the recommendation for charge-off are unique to the type of loan being considered. Commercial loans rated as substandard nonaccrual or lower will first have a collateral evaluation completed in accordance with the guidance on impaired loans. Once the collateral evaluation has been completed, a specific allocation of allowance is made based upon the results of the evaluation. The remaining balance remains a nonperforming loan with the original terms and interest rate intact (not restructured). In the event the loan is unsecured, the loan would have been charged-off at the recognition of impairment. Commercial real estate loans rated as impaired will also have an initial collateral evaluation completed in accordance with the guidance on impaired loans. An updated real estate valuation is ordered and the collateral evaluation is modified to reflect any variations in value. A specific allocation of allowance is made for any anticipated collateral shortfall. The remaining balance remains a nonperforming loan with the original terms and interest rate intact (not restructured). The process of charge-off for residential mortgage loans begins upon a loan becoming delinquent for 90 days and not in the process of collection. The existing appraisal is reviewed and a lien search is obtained to determine lien position and any instances of intervening liens. A new appraisal of the property will be ordered if deemed necessary by management and a collateral evaluation is completed. The loan will then be charged down to the value indicated in the evaluation. Consumer loans (including home equity loans and other consumer loans) are recommended for charge-off after reaching delinquency of 90 days and the loan is not in the process of collection. The collateral shortfall of the consumer loan is recommended for charge-off at this point. As noted above, Mid Penn assesses a specific allocation for commercial loans and commercial real estate loans. The remaining balance remains a nonperforming loan with the original terms and interest rate intact (not restructured). In addition, Mid Penn takes a preemptive step when any commercial loan becomes classified under its internal classification system. A preliminary collateral evaluation, in accordance with the guidance on impaired loans, is prepared using the existing collateral information in the loan file. This process allows Mid Penn to review both the credit and documentation files to determine the status of the information needed to make a collateral evaluation. This collateral evaluation is preliminary but allows Mid Penn to determine if any potential collateral shortfalls exist. It is Mid Penn’s policy to obtain updated third party valuations on all impaired loans collateralized by real estate as soon as practically possible of the credit being classified as substandard nonaccrual. Prior to receipt of the updated real estate valuation Mid Penn will use any existing real estate valuation to determine any potential allowance issues; however, no allowance recommendation will be made until such time Mid Penn is in receipt of the updated valuation. The Asset Recovery department employs an electronic tracking system to monitor the receipt of and need for updated appraisals. To date, there have been no material time lapses noted with the above processes. In some instances Mid Penn is not holding real estate as collateral and is relying on business assets (personal property) for repayment. In these circumstances a collateral inspection is performed by Mid Penn personnel to determine an estimated value. The value is based on net book value, as provided by the financial statements, and discounted accordingly based on determinations made by management. Occasionally, Mid Penn will employ an outside service to provide a fair estimate of value based on auction sales or private sales. Management reviews the estimates of these third parties and discounts them accordingly based on management’s judgment, if deemed necessary. For impaired loans with no valuation allowance required, Mid Penn’s practice of obtaining independent third party market valuations on the subject property as soon as practically possible of the credit being placed on nonaccrual status sometimes indicates that the loan to value ratio is sufficient to obviate the need for a specific allocation in spite of significant deterioration in real estate values in Mid Penn’s primary market area. These circumstances are determined on a case by case analysis of the impaired loans. Mid Penn actively monitors the values of collateral on impaired loans. This monitoring may require the modification of collateral values over time or changing circumstances by some factor, either positive or negative, from the original values. All collateral values will be assessed by management at least every 12 months for possible revaluation by an independent third party. An unallocated component is maintained to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance for loan and lease losses covers several considerations that are not specifically measureable through either the specific and general components. For example, we believe that we could face credit risks and uncertainties, not reflected in recent historical losses or qualitative factor assessments, associated with unpredictable changes in economic growth or business conditions in our markets or for certain industries in which we have commercial loan borrowers, or unanticipated stresses to the values of real estate held as collateral. Any or all of these additional issues can adversely affect our borrowers’ ability to timely repay their loans. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, Mid Penn does not separately identify individual residential mortgage loans, home equity loans and other consumer loans for impairment disclosures, unless such loans are the subject of a troubled debt restructuring agreement. Loans whose terms are modified are classified as troubled debt restructurings if the borrowers have been granted concessions 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 or an extension of a loan’s stated maturity date. Nonaccrual troubled debt restructurings are restored to accrual status if principal and interest payments, under the modified terms, are current for six consecutive months after modification. Loans classified as troubled debt restructurings are designated as impaired. The allowance calculation methodology includes further segregation of loan classes into risk rating categories. The borrower’s overall financial condition, repayment sources, guarantors, and value of collateral, if appropriate, are 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 criticized as 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. Any loans not classified as noted above are rated pass. In addition, Federal and State regulatory agencies, as an integral part of their examination process, periodically review the Bank’s allowance for loan and lease losses and may require the Bank 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, management believes the current level of the allowance for loan losses is adequate. Acquired Loans Loans that Mid Penn acquires in connection with business combinations are recorded at fair value with no carryover of the existing related allowance for loan losses. Fair value of the loans involves estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest. The excess of cash flows expected at acquisition over the estimated fair value is referred to as the accretable discount and is recognized into interest income over the remaining life of the loan. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable discount. These loans are accounted for under the Accounting Standard Codification (“ASC”) 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality Loans acquired through business combinations that do meet the specific criteria of ASC 310-30 are individually evaluated each period to analyze expected cash flows. To the extent that the expected cash flows of a loan have decreased due to credit deterioration, Mid Penn establishes an allowance. Loans acquired through business combinations that do not meet the specific criteria of ASC 310-30 are accounted for under ASC 310-20. These loans are initially recorded at fair value, and include credit and interest rate marks associated with acquisition accounting adjustments. Purchase premiums or discounts are subsequently amortized as an adjustment to yield over the estimated contractual lives of the loans. There is no allowance for loan losses established at the acquisition date for acquired performing loans. An allowance for loan losses is recorded for any credit deterioration in these loans subsequent to acquisition. Acquired loans that met the criteria for impaired or nonaccrual of interest prior to the acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent if Mid Penn expects to fully collect the new carrying value (i.e. fair value) of the loans. As such, Mid Penn may no longer consider the loan to be nonaccrual or nonperforming and may accrue interest on these loans, including the impact of any accretable discount. In addition, charge-offs on such loans would be first applied to the nonaccretable difference portion of the fair value adjustment. (g) Bank Premises and Equipment Land is carried at cost. Buildings, furniture, fixtures, equipment, land improvements, and leasehold improvements are stated at cost less accumulated depreciation. Depreciation is computed by the straight-line method over the estimated useful lives of the assets. Building assets are depreciated using an estimated useful life of five to fifty years. Furniture, fixtures, and equipment are depreciated using an estimated useful life of three to ten years. Land improvements are depreciated over an estimated useful life of ten to twenty years. Leasehold improvements are depreciated using an estimated useful life that is the lesser of the remaining life of the lease or ten to thirty years. Maintenance and normal repairs are charged to expense when incurred, while major additions and improvements are capitalized. Gains and losses on disposals are reflected in current operations. Bank premises and equipment designated as held for sale are carried at the lower of cost or market value. (h) Restricted Investments in Bank Stocks Restricted investments in bank stocks represent required investments in the common stock of correspondent banks. As a member of the FHLB and Atlantic Community Bankers Bank (“ACBB”), the Bank is required to own restricted stock investments in these correspondent banks, which is carried at cost. The total amount of these restricted stock investments was $4,384,000 December 31, 2017 and $2,443,000 at December 31, 2016. This increase was attributed to Mid Penn’s shift from a short-term selling position to a short-term borrowing position in 2017. Total dividends received in 2017 and 2016 totaled $114,000 and $135,000, respectively. (i) Foreclosed Assets Held for Sale Foreclosed assets held for sale consist primarily of real estate acquired through, or in lieu of, foreclosure in settlement of debt, and are recorded at fair value less cost to sell at the date of transfer, establishing a new cost basis. Any valuation adjustments required at the date of transfer are charged to the allowance for loan losses. Subsequent to acquisition, foreclosed assets are carried at fair value less costs of disposal, based upon periodic evaluations that consider changes in market conditions and development and disposal costs. Operating results from assets acquired in satisfaction of debt, including rental income less operating costs and gains or losses on the sale of, or the periodic evaluation of foreclosed assets, are recorded in noninterest expense. As of December 31, 2017, Mid Penn had $42,000 of residential real estate held in other real estate owned. There was $308,000 in loans for which formal foreclosure proceedings were in process at December 31, 2017. As of December 31, 2016, Mid Penn had $57,000 of residential real estate held in other real estate owned. There was $426,000 in loans for which formal foreclosure proceedings were in process at December 31, 2016. (j) Mortgage Servicing Rights Mortgage servicing rights are recognized as assets upon the sale of a mortgage loan. A portion of the cost of the loan is allocated to the servicing right based upon relative fair value. The fair value of servicing rights is based on the present value of estimated future cash flows of mortgages sold, stratified by rate and maturity date. Assumptions that are incorporated in the valuation of servicing rights include assumptions about prepayment speeds on mortgages and the cost to service loans. Servicing rights are reported in core deposit and other intangibles in the Consolidated Balance Sheets and are amortized over the estimated period of future servicing income to be received on the underlying mortgage loans. Th

Mergers and Acquisitions

Mergers and Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Mergers and Acquisitions	(4) Mergers and Acquisitions On January 8, 2018, Mid Penn announced the successful completion of the acquisition of The Scottdale Bank & Trust Company (“Scottdale”). On January 16, 2018, Mid Penn entered into an Agreement and Plan of Merger with First Priority Financial Corp. (“First Priority”). More information on these transactions can be found in Item 1 – Business and Note 26 – Subsequent Events. Phoenix Bancorp, Inc . On March 1, 2015, Phoenix Bancorp, Inc. (“Phoenix”) merged with, and into, Mid Penn, with Mid Penn continuing as the surviving entity. Simultaneously with the consummation of the foregoing merger, Miners Bank (“Miners”), a Pennsylvania-state chartered bank and wholly-owned subsidiary of Phoenix, merged with and into the Bank. As part of this transaction, Phoenix shareholders received either 3.167 shares of Mid Penn common stock or $51.60 in cash in exchange for each share of Phoenix common stock. Holders of contingent rights issued by Phoenix received approximately 0.414 shares of Mid Penn common stock as settlement of such rights. As a result, Mid Penn issued 723,851 shares of common stock with an acquisition date fair value of approximately $11,292,000, based on the closing stock price of Mid Penn common stock on February 27, 2015 of $15.60, and cash of $2,949,000. Including an insignificant amount of cash paid in lieu of fractional shares, the fair value of total consideration paid was $14,241,000. Additionally, as part of this transaction, on March 1, 2015, Mid Penn assumed all of the liabilities and obligations of Phoenix with respect to 1,750 shares of Phoenix’s preferred stock issued to the United States Treasury (“Treasury”) in connection with the Small Business Lending Fund and issued 1,750 shares of its own Senior Non-Cumulative Perpetual Preferred Stock, Series C that had a $1,000 liquidation preference per share (the “SBLF Preferred Shares”), to the Treasury. The SBLF Preferred Shares qualified as Tier 1 Capital and had terms and conditions identical to those shares of preferred stock issued by Phoenix to the Treasury. The assets and liabilities of Miners and Phoenix were recorded on the consolidated balance sheet at their estimated fair value as of March 1, 2015, and their results of operations have been included in the consolidated income statement since that date. Included in the purchase price was goodwill and a core deposit intangible of $2,902,000 and $578,000, respectively. The core deposit intangible will be amortized over a ten-year period using a sum of the year’s digits basis. The goodwill is not taxable and will not be amortized, but will be measured annually for impairment or more frequently if circumstances require. Core deposit intangible amortization expense projected for the next five years beginning in 2018 is estimated to be $75,000, $65,000, $54,000, $44,000, and $33,000 per year, respectively, and $37,000 in total for years after 2022. The allocation of the purchase price of the Phoenix acquisition is as follows: (Dollars in thousands) Assets acquired: Cash and cash equivalents $ 11,044 Investment securities 11,331 Loans 110,363 Goodwill 2,902 Core deposit and other intangibles 578 Other assets 7,489 Total assets acquired 143,707 Liabilities assumed: Deposits 123,238 FHLB borrowings 3,570 Other liabilities 908 Total liabilities assumed 127,716 Equity acquired: Preferred stock 1,750 Total equity acquired and liabilities assumed 129,466 Consideration paid $ 14,241 Cash paid $ 2,949 Fair value of common stock issued, including replacement equity awards 11,292 The following table summarizes the estimated fair value of the assets acquired and liabilities and equity assumed with the Phoenix acquisition. (Dollars in thousands) Total purchase price $ 14,241 Net assets acquired: Cash and cash equivalents 11,044 Investment securities 11,331 Restricted stock 509 Loans 110,363 Bank owned life insurance 3,673 Premises and equipment 1,792 Deferred income taxes 503 Accrued interest receivable 388 Core deposit and other intangibles 578 Other assets 624 Deposits (123,238 ) FHLB borrowings (3,570 ) Accrued interest payable (32 ) Other liabilities (876 ) Preferred stock (1,750 ) 11,339 Goodwill $ 2,902 The fair value of the financial assets acquired from Phoenix included loans receivable with a gross amortized cost basis of $112,816,000. 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. (Dollars in thousands) Gross amortized cost basis at March 1, 2015 $ 112,816 Market rate adjustment 270 Credit fair value adjustment on pools of homogeneous loans (1,461 ) Credit fair value adjustment on impaired loans (1,262 ) Fair value of purchased loans at March 1, 2015 $ 110,363 The market rate adjustment represents the movement in market interest rates, irrespective of credit adjustments, compared to the stated rates of the acquired loans. The credit adjustment made on pools of homogeneous loans represents the changes in credit quality of the underlying borrowers from the loan inception to the acquisition date. The credit adjustment on impaired loans is derived in accordance with ASC 310-30 and represents the portion of the loan balance that has been deemed uncollectible based on our expectations of future cash flows for each respective loan. The information about the acquired Phoenix loans accounted for under ASC 310-30 as of March 1, 2015 is as follows: (Dollars in thousands) Contractually required principal and interest at acquisition $ 3,548 Contractual cash flows not expected to be collected (nonaccretable discount) (804 ) Expected cash flows at acquisition 2,744 Interest component of expected cash flows (accretable discount) (458 ) Fair value of acquired loans $ 2,286 The following table presents unaudited pro forma information about the merger between Mid Penn and Phoenix. The pro forma information does not necessarily reflect the results of operations that would have occurred had Mid Penn merged with Phoenix at the beginning of 2015. Supplemental pro forma earnings for 2015 were adjusted to exclude $762,000 of merger related costs. The pro forma financial information does not include the impact of possible business model changes, nor does it consider any potential impacts of current market conditions or revenues, expense efficiencies, or other factors. The pro forma data is intended for informational purposes and is not indicative of the future results of operations. The following table presents the unaudited pro forma information for the year ended December 31, 2015, as if the merger between Mid Penn and Phoenix had been completed on January 1, 2014. (Dollars in thousands, except per share data) Net interest income after loan loss provision $ 31,454 Noninterest income 4,152 Noninterest expense 27,817 Net income available to common shareholders 5,811 Net income per common share 1.38 The amount of total revenue, consisting of interest income plus noninterest income specifically related to Phoenix for the period beginning March 1, 2015, included in the consolidated statements of income of Mid Penn for the year ended December 31, 2015, was $4,244,000. The net income specifically related to Phoenix for the period beginning March 1, 2015, included in the consolidated statements of income of Mid Penn for the year ended December 31, 2015, was $747,000.

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Accumulated Other Comprehensive (Loss) Income	(5) Accumulated Other Comprehensive (Loss) Income The components of accumulated other comprehensive (loss) income, net of taxes, are as follows: (Dollars in thousands) Unrealized (Loss) Gain on Securities Defined Plan Liability Accumulated Other Comprehensive (Loss) Income Balance - December 31, 2017 $ (2,159 ) $ 85 $ (2,074 ) Balance - December 31, 2016 $ (2,919 ) $ 66 $ (2,853 )

Restrictions on Cash and Due fr

Restrictions on Cash and Due from Bank Accounts	12 Months Ended
	Dec. 31, 2017
Restrictions On Cash And Due From Bank Accounts [Abstract]
Restrictions on Cash and Due from Bank Accounts	(6) Restrictions on Cash and Due from Bank Accounts The Bank is required to maintain reserve balances with the Federal Reserve Bank of Philadelphia. There was no required reserve balance at December 31, 2017 and December 31, 2016 because the Bank had sufficient vault cash available.

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2017
Securities Financing Transactions Disclosures [Abstract]
Investment Securities	(7) Investment Securities Securities to be held for indefinite periods, but not intended to be held to maturity, are classified as available for sale and carried at fair value. Securities held for indefinite periods include securities that management intends to use as part of its asset and liability management strategy and that may be sold in response to liquidity needs, changes in interest rates, resultant prepayment risk, and other factors related to interest rate and resultant prepayment risk changes. Securities to be held to maturity are carried at amortized cost. Realized gains and losses on dispositions are based on the net proceeds and the adjusted book value of the securities sold, using the specific identification method. Unrealized gains and losses on investment securities available for sale are based on the difference between book value and fair value of each security. These gains and losses are credited or charged to other comprehensive income (loss), whereas realized gains and losses flow through Mid Penn’s consolidated statements of income. ASC Topic 320, Investments – Debt and Equity Securities In instances when a determination is made that other-than-temporary impairment exists but the investor does not intend to sell the debt security and it is not more likely than not that it will be required to sell the debt security prior to its anticipated recovery, this guidance changes the presentation and amount of the other-than-temporary impairment recognized in the income statement. The other-than-temporary impairment is separated into (a) the amount of the total other-than-temporary impairment related to a decrease in cash flows expected to be collected from the debt security (the credit loss) and (b) the amount of the total other-than-temporary impairment related to all other factors. The amount of the total other-than-temporary impairment related to the credit loss is recognized in earnings. The amount of the total other-than-temporary impairment related to all other factors is recognized in other comprehensive income (loss). In assessing potential other-than-temporary impairment for equity securities, consideration is given to management’s intent and ability to hold the securities until recovery of unrealized losses. Mid Penn had no other-than-temporary impaired debt or equity securities in 2017, 2016, and 2015. At December 31, 2017 and 2016, amortized cost, fair value, and unrealized gains and losses on investment securities are as follows: (Dollars in thousands) Amortized Unrealized Unrealized Fair December 31, 2017 Cost Gains Losses Value Available for sale securities: U.S. Treasury and U.S. government agencies $ 40,125 $ — $ 1,395 $ 38,730 Mortgage-backed U.S. government agencies 26,398 2 569 25,831 State and political subdivision obligations 27,775 7 739 27,043 Corporate debt securities 1,000 5 — 1,005 Equity securities 900 — 44 856 Total available for sale securities 96,198 14 2,747 93,465 Held to maturity securities: U.S. Treasury and U.S. government agencies $ 10,984 $ — $ 90 $ 10,894 Mortgage-backed U.S. government agencies 53,472 — 523 52,949 State and political subdivision obligations 36,900 41 301 36,640 Corporate debt securities — — — — Equity securities — — — — Total held to maturity securities 101,356 41 914 100,483 Total $ 197,554 $ 55 $ 3,661 $ 193,948 (Dollars in thousands) Amortized Unrealized Unrealized Fair December 31, 2016 Cost Gains Losses Value Available for sale securities: U.S. Treasury and U.S. government agencies $ 48,520 $ 34 $ 1,542 $ 47,012 Mortgage-backed U.S. government agencies 26,181 17 579 25,619 State and political subdivision obligations 61,079 91 2,332 58,838 Corporate debt securities 1,000 — — 1,000 Equity securities 1,268 — 112 1,156 $ 138,048 $ 142 $ 4,565 $ 133,625 There were no held-to-maturity securities as of December 31, 2016. Estimated fair values of debt securities are based on quoted market prices, where applicable. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments, adjusted for differences between the quoted instruments and the instruments being valued. Investment securities having a fair value of $141,465,000 at December 31, 2017, and $131,469,000 at December 31, 2016, were pledged primarily to secure public deposits. The following table presents gross unrealized losses and fair value of investments aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31, 2017 and 2016. (Dollars in thousands) Less Than 12 Months 12 Months or More Total December 31, 2017 Number of Securities Fair Value Unrealized Losses Number of Securities Fair Value Unrealized Losses Number of Securities Fair Value Unrealized Losses Available for sale securities: U.S. Treasury and U.S. government agencies 3 $ 5,008 $ 184 18 $ 33,722 $ 1,211 21 $ 38,730 $ 1,395 Mortgage-backed U.S. government agencies 4 5,267 75 15 20,497 494 19 25,764 569 State and political subdivision obligations 11 6,144 102 40 19,091 637 51 25,235 739 Corporate debt securities 0 — — 0 — — 0 — — Equity securities 0 — — 1 506 44 1 506 44 Total temporarily impaired available for sale securities 18 16,419 361 74 73,816 2,386 92 90,235 2,747 Held to maturity securities: U.S. Treasury and U.S. government agencies 0 $ — $ — 4 $ 10,894 $ 90 4 $ 10,894 $ 90 Mortgage-backed U.S. government agencies 0 — — 35 52,949 523 35 52,949 523 State and political subdivision obligations 0 — — 77 29,976 301 77 29,976 301 Corporate debt securities 0 — — 0 — — 0 — — Equity securities 0 — — 0 — — 0 — — Total temporarily impaired held to maturity securities 0 — — 116 93,819 914 116 93,819 914 Total 18 $ 16,419 $ 361 190 $ 167,635 $ 3,300 208 $ 184,054 $ 3,661 (Dollars in thousands) Less Than 12 Months 12 Months or More Total December 31, 2016 Number of Securities Fair Value Unrealized Losses Number of Securities Fair Value Unrealized Losses Number of Securities Fair Value Unrealized Losses Available for sale securities: U.S. Treasury and U.S. government agencies 23 $ 43,698 $ 1,542 0 $ — $ — 23 $ 43,698 $ 1,542 Mortgage-backed U.S. government agencies 18 24,321 579 0 — — 18 24,321 579 State and political subdivision obligations 108 50,582 2,332 0 — — 108 50,582 2,332 Corporate debt securities 0 — — 0 — — 0 — — Equity securities 0 — — 2 1,056 112 2 1,056 112 Total temporarily impaired available for sale securities 149 $ 118,601 $ 4,453 2 $ 1,056 $ 112 151 $ 119,657 $ 4,565 There were no held-to-maturity securities as of December 31, 2016. Management evaluates securities for other-than-temporary impairment on a quarterly basis; and more frequently when economic or market concerns warrant such evaluation. Consideration is given to the length of time and the extent to which the fair value has been less than cost, and the financial condition and near term prospects of the issuer. In addition, for debt securities, Mid Penn considers (a) whether management has the intent to sell the security, (b) it is more likely than not that management will be required to sell the security prior to its anticipated recovery, and (c) whether management expects to recover the entire amortized cost basis. For equity securities, management considers the intent and ability to hold securities until recovery of unrealized losses. The majority of the investment portfolio is comprised of mortgage-backed U.S. government agencies and state and political subdivision obligations. For the investment securities with an unrealized loss, Mid Penn has concluded, based on its analysis, that the unrealized losses in the investments are primarily caused by the movement of interest rates, and the contractual terms of these investments do not permit the issuer to settle the securities at a price less than the par value of the investment. At December 31, 2017, the majority of the unrealized losses on securities in an unrealized loss position were attributed to state and political subdivision obligations and mortgage-back U.S. government agencies. At December 31, 2016, the majority of the unrealized losses on securities in an unrealized loss position were attributed to state and political subdivision obligations and U.S. Treasury and government agencies. Because Mid Penn does not intend to sell these investments and it is not likely it will be required to sell these investments before a recovery of fair value, which may be maturity, Mid Penn does not consider the securities with unrealized losses to be other-than-temporarily impaired as losses relate to changes in interest rates and not erosion of credit quality. Gross realized gains and losses on sales of available-for-sale securities for the years ended December 31, 2017, 2016, and 2015 are shown in the table below. (Dollars in thousands) For the year ended December 31, 2017 2016 2015 Realized gains $ 246 $ 1,927 $ 325 Realized losses (204 ) (881 ) — Net gains $ 42 $ 1,046 $ 325 The table below is the maturity distribution of investment securities at amortized cost and fair value at December 31, 2017. (Dollars in thousands) Available for Sale Held to Maturity Amortized Fair Amortized Fair December 31, 2017 Cost Value Cost Value Due in 1 year or less $ 100 $ 100 $ 2,001 $ 1,989 Due after 1 year but within 5 years 12,072 11,825 9,431 9,357 Due after 5 years but within 10 years 46,307 44,779 35,941 35,679 Due after 10 years 10,771 10,424 511 509 69,250 67,128 47,884 47,534 Mortgage-backed securities 26,398 25,831 53,472 52,949 Equity securities 550 506 — — $ 96,198 $ 93,465 $ 101,356 $ 100,483

Loans and Allowance for Loan an

Loans and Allowance for Loan and Lease Losses	12 Months Ended
	Dec. 31, 2017
Accounts Notes Loans And Financing Receivable Gross Allowance And Net [Abstract]
Loans and Allowance for Loan and Lease Losses	(8) Loans and Allowance for Loan and Lease Losses The classes of the loan portfolio, summarized by the aggregate pass rating, net of deferred fees and costs of $464,000 and $196,000 as of December 31, 2017 and 2016, respectively, and the classified ratings of special mention, substandard, and doubtful within Mid Penn’s internal risk rating system as of December 31, 2017 and 2016, are noted below: (Dollars in thousands) December 31, 2017 Pass Special Mention Substandard Doubtful Total Commercial and industrial $ 182,168 $ 453 $ 5,412 $ — $ 188,033 Commercial real estate 505,397 1,435 8,180 — 515,012 Commercial real estate - construction 61,667 182 487 — 62,336 Lease financing 229 — — — 229 Residential mortgage 97,814 157 1,062 — 99,033 Home equity 41,479 105 309 — 41,893 Consumer 3,868 — — — 3,868 $ 892,622 $ 2,332 $ 15,450 $ — $ 910,404 (Dollars in thousands) December 31, 2016 Pass Special Mention Substandard Doubtful Total Commercial and industrial $ 170,780 $ 937 $ 801 $ — $ 172,518 Commercial real estate 437,592 1,683 7,249 — 446,524 Commercial real estate - construction 52,888 202 1,286 — 54,376 Lease financing 425 — — — 425 Residential mortgage 97,994 107 1,356 — 99,457 Home equity 37,242 142 224 — 37,608 Consumer 3,016 — — — 3,016 $ 799,937 $ 3,071 $ 10,916 $ — $ 813,924 Impaired loans by loan portfolio class as of December 31, 2017 and 2016 are summarized as follows: December 31, 2017 December 31, 2016 (Dollars in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With no related allowance recorded: Commercial and industrial $ — $ 13 $ — $ 4 $ 9 $ — Commercial real estate 3,424 4,056 — 726 1,792 — Commercial real estate - construction — — — 618 618 — Lease financing — — — — — — Residential mortgage 760 877 — 848 882 — Home equity 260 295 — 111 129 — Consumer — — — — — — With no related allowance recorded and acquired with credit deterioration: Commercial and industrial $ — $ — $ — $ — $ — $ — Commercial real estate 555 555 — 842 842 — Commercial real estate - construction — — — — — — Lease financing — — — — — — Residential mortgage 306 306 — 389 389 — Home equity — — — — — — Consumer — — — — — — With an allowance recorded: Commercial and industrial $ 4,434 $ 4,460 $ 136 $ 56 $ 62 $ 6 Commercial real estate 1,423 1,589 293 2,520 2,646 711 Commercial real estate - construction 487 492 100 242 242 72 Lease financing — — — — — — Residential mortgage — — — 68 68 68 Home equity — — — 29 49 1 Consumer — — — — — — Total: Commercial and industrial $ 4,434 $ 4,473 $ 136 $ 60 $ 71 $ 6 Commercial real estate 5,402 6,200 293 4,088 5,280 711 Commercial real estate - construction 487 492 100 860 860 72 Lease financing — — — — — — Residential mortgage 1,066 1,183 — 1,305 1,339 68 Home equity 260 295 — 140 178 1 * Loans acquired with credit deterioration are presented net of credit fair value adjustment. The average recorded investment of impaired loans and related interest income recognized for the years ended December 31, 2017, 2016, and 2015 are summarized as follows: December 31, 2017 December 31, 2016 December 31, 2015 (Dollars in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With no related allowance recorded: Commercial and industrial $ 15 $ — $ 9 $ — $ 19 $ — Commercial real estate 1,915 279 820 — 1,051 14 Commercial real estate - construction 164 — 124 — — — Lease financing — — — — — — Residential mortgage 890 18 821 21 816 8 Home equity 218 6 75 — 107 — Consumer — — — — — — With no related allowance recorded and acquired with credit deterioration: Commercial and industrial $ — $ — $ — $ — $ — $ 205 Commercial real estate 651 110 810 164 926 350 Commercial real estate - construction — — — — — — Lease financing — — — — — — Residential mortgage 332 — 378 4 400 — Home equity — — — — — 3 Consumer — — — — — — With an allowance recorded: Commercial and industrial $ 1,779 $ — $ 59 $ — $ 123 $ — Commercial real estate 1,446 — 2,177 — 1,721 — Commercial real estate - construction 488 — 48 — — — Lease financing — — — — — — Residential mortgage — — 14 — 25 — Home equity — — 32 — — — Consumer — — — — — — Total: Commercial and industrial $ 1,794 $ — $ 68 $ — $ 142 $ 205 Commercial real estate 4,012 389 3,807 164 3,698 364 Commercial real estate - construction 652 — 172 — — — Lease financing — — — — — — Residential mortgage 1,222 18 1,213 25 1,241 8 Home equity 218 6 107 — 107 3 Nonaccrual loans by loan portfolio class as of December 31, 2017 and 2016 are summarized as follows: (Dollars in thousands) 2017 2016 Commercial and industrial $ 4,434 $ 4 Commercial real estate 4,902 2,939 Commercial real estate - construction 487 860 Residential mortgage 492 715 Home equity 260 140 $ 10,575 $ 4,658 If nonaccrual loans and leases had been current in accordance with their original terms and had been outstanding throughout the period or since origination, if held for part of the period, Mid Penn would have recorded interest income on these loans of $780,000, $778,000, and $798,000, in the years ended December 31, 2017, 2016, and 2015, respectively. Mid Penn has no commitments to lend additional funds to borrowers with impaired or nonaccrual loans. The performance and credit quality of the loan portfolio is also monitored by the analyzing the age of the loans receivable as determined by the length of time a recorded payment is past due. The classes of the loan portfolio summarized by the past due status as of December 31, 2017 and 2016 are summarized as follows: (Dollars in thousands) December 31, 2017 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days Total Past Due Current Total Loans Loans Receivable > 90 Days and Accruing Commercial and industrial: Commercial and industrial $ 4,439 $ 16 $ — $ 4,455 $ 183,578 $ 188,033 $ — Commercial real estate: Commercial real estate — — 3,669 3,669 510,788 514,457 — Acquired with credit deterioration 500 — 55 555 - 555 — Commercial real estate - construction: Commercial real estate - construction — — 487 487 61,849 62,336 — Lease financing: Lease financing — — — — 229 229 — Residential mortgage: Residential mortgage 310 467 177 954 97,773 98,727 — Acquired with credit deterioration — 31 193 224 82 306 — Home equity: Home equity 54 98 250 402 41,491 41,893 — Consumer: Consumer 3 — — 3 3,865 3,868 — Total $ 5,306 $ 612 $ 4,831 $ 10,749 $ 899,655 $ 910,404 $ — (Dollars in thousands) December 31, 2016 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days Total Past Due Current Total Loans Loans Receivable > 90 Days and Accruing Commercial and industrial: Commercial and industrial $ 164 $ 12 $ 4 $ 180 $ 172,338 $ 172,518 $ — Commercial real estate: Commercial real estate 475 — 1,004 1,479 444,203 445,682 — Acquired with credit deterioration — — 59 59 783 842 59 Commercial real estate - construction: Commercial real estate - construction — 404 84 488 53,888 54,376 — Lease financing: Lease financing — — — — 425 425 — Residential mortgage: Residential mortgage 548 124 237 909 98,159 99,068 — Acquired with credit deterioration — — 238 238 151 389 — Home equity: Home equity 33 13 125 171 37,437 37,608 — Consumer: Consumer — — — — 3,016 3,016 — Total $ 1,220 $ 553 $ 1,751 $ 3,524 $ 810,400 $ 813,924 $ 59 Activity in the allowance for loan and lease losses for the years ended December 31, 2017, 2016, and 2015, and the recorded investment in loans receivable as of December 31, 2017, 2016, and 2015 are as follows: (Dollars in thousands) December 31, 2017 Commercial and industrial Commercial real estate Commercial real estate - construction Lease financing Residential mortgage Home equity Consumer Unallocated Total Allowance for loan and lease losses: Beginning balance $ 1,580 $ 4,323 $ 144 $ 1 $ 541 $ 379 $ 3 $ 212 $ 7,183 Charge-offs (25 ) (322 ) — — (102 ) (20 ) (28 ) — (497 ) Recoveries 26 553 — — 4 5 7 — 595 Provisions 214 (119 ) 34 (1 ) (15 ) 59 21 132 325 Ending balance 1,795 4,435 178 — 428 423 3 344 7,606 Ending balance: individually evaluated for impairment 136 293 100 — — — — — 529 Ending balance: collectively evaluated for impairment $ 1,659 $ 4,142 $ 78 $ - $ 428 $ 423 $ 3 $ 344 $ 7,077 Loans receivable: Ending balance $ 188,033 $ 515,012 $ 62,336 $ 229 $ 99,033 $ 41,893 $ 3,868 $ — $ 910,404 Ending balance: individually evaluated for impairment 4,434 4,847 487 — 760 260 — — 10,788 Ending balance: acquired with credit deterioration — 555 — — 306 — — — 861 Ending balance: collectively evaluated for impairment $ 183,599 $ 509,610 $ 61,849 $ 229 $ 97,967 $ 41,633 $ 3,868 $ — $ 898,755 (Dollars in thousands) December 31, 2016 Commercial and industrial Commercial real estate Commercial real estate - construction Lease financing Residential mortgage Home equity Consumer Unallocated Total Allowance for loan and lease losses: Beginning balance $ 1,393 $ 3,552 $ 153 $ 1 $ 534 $ 317 $ 12 $ 206 $ 6,168 Charge-offs (820 ) (216 ) — — (4 ) (25 ) (42 ) — (1,107 ) Recoveries 4 211 — — 26 - 11 — 252 Provisions 1,003 776 (9 ) - (15 ) 87 22 6 1,870 Ending balance 1,580 4,323 144 1 541 379 3 212 7,183 Ending balance: individually evaluated for impairment 6 711 72 — 68 1 — — 858 Ending balance: collectively evaluated for impairment $ 1,574 $ 3,612 $ 72 $ 1 $ 473 $ 378 $ 3 $ 212 $ 6,325 Loans receivable: Ending balance $ 172,518 $ 446,524 $ 54,376 $ 425 $ 99,457 $ 37,608 $ 3,016 $ — $ 813,924 Ending balance: individually evaluated for impairment 60 3,246 860 — 916 140 — — 5,222 Ending balance: acquired with credit deterioration — 842 — — 389 — — — 1,231 Ending balance: collectively evaluated for impairment $ 172,458 $ 442,436 $ 53,516 $ 425 $ 98,152 37,468 $ 3,016 $ — $ 807,471 (Dollars in thousands) December 31, 2015 Commercial and industrial Commercial real estate Commercial real estate - construction Lease financing Residential mortgage Home equity Consumer Unallocated Total Allowance for loan and lease losses: Beginning Balance $ 1,393 $ 3,925 $ 33 $ 2 $ 450 $ 653 $ 35 $ 225 $ 6,716 Charge-offs (130 ) (1,569 ) — — (35 ) (36 ) (14 ) — (1,784 ) Recoveries 12 75 — — 44 29 11 — 171 Provisions 118 1,121 120 (1 ) 75 (329 ) (20 ) (19 ) 1,065 Ending balance 1,393 3,552 153 1 534 317 12 206 6,168 Ending balance: individually evaluated for impairment 51 429 — — 23 — — — 503 Ending balance: collectively evaluated for impairment $ 1,342 $ 3,123 $ 153 $ 1 $ 511 $ 317 $ 12 $ 206 $ 5,665 Loans receivable: Ending balance $ 160,261 $ 369,464 $ 68,068 $ 727 $ 100,665 $ 33,411 $ 3,917 $ — $ 736,513 Ending balance: individually evaluated for impairment 127 2,970 — — 1,361 115 — — 4,573 Ending balance: acquired with credit deterioration — 931 — — 400 — — — 1,331 Ending balance: collectively evaluated for impairment $ 160,134 $ 365,563 $ 68,068 $ 727 $ 98,904 33,296 $ 3,917 $ — $ 730,609 The recorded investments in troubled debt restructured loans at December 31, 2017 and 2016 are as follows: (Dollars in thousands) Pre-Modification Post-Modification December 31, 2017 Outstanding Investment Outstanding Recorded Investment Recorded Investment Commercial and industrial $ 4,110 $ 4,460 $ 4,434 Commercial real estate 5,735 5,581 4,593 Residential mortgage 691 689 544 $ 10,536 $ 10,730 $ 9,571 (Dollars in thousands) Pre-Modification Post-Modification December 31, 2016 Outstanding Recorded Investment Outstanding Recorded Investment Recorded Investment Commercial and industrial $ 40 $ 35 $ 5 Commercial real estate 4,569 4,031 2,871 Residential mortgage 759 757 639 $ 5,368 $ 4,823 $ 3,515 At December 31, 2017, Mid Penn’s troubled debt restructured loans totaled $9,571,000, and included four loans, totaling $544,000, representing accruing impaired loans in compliance with the terms of the modification. Of the $544,000, three are accruing impaired residential mortgages to unrelated borrowers totaling $540,000 and the other one is an accruing impaired home equity loan of $4,000. The remaining $9,027,000 of troubled debt restructured loans represent fifteen loans among seven relationships, are nonaccrual impaired loans, and resulted in a collateral evaluation in accordance with the guidance on impaired loans. Two large relationships accounted for $7,284,000 of the $9,027,000 nonaccrual impaired troubled debt restructured loan total. As a result of the evaluation, a specific allocation and, subsequently, charge-offs have been taken as appropriate. As of December 31, 2017, there was $66,000 of charge-offs associated with troubled debt restructured loans while under a forbearance agreement. As of December 31, 2017, there were no defaulted troubled debt restructured loans, as all troubled debt restructured loans were current with respect to their associated forbearance agreements. There were also no defaults on troubled debt restructured loans within twelve months of restructure during 2017. One forbearance agreement was negotiated during 2008, six forbearance agreements were negotiated during 2009, one was negotiated during 2013, one was negotiated during 2014, and ten were negotiated during 2017. At December 31, 2016, Mid Penn’s troubled debt restructured loans totaled $3,515,000, and included five loans, totaling $877,000, representing accruing impaired loans in compliance with the terms of the modification. Of the $877,000, four were accruing impaired residential mortgages to unrelated borrowers totaling $571,000 and the other one was an accruing impaired commercial real estate loan for $306,000. The remaining $2,638,000 of troubled debt restructured loans represent ten loans among four relationships, were nonaccrual impaired loans, and resulted in a collateral evaluation in accordance with the guidance on impaired loans. Two large relationships accounted for $2,170,000 of the $2,638,000 nonaccrual impaired troubled debt restructured loan total. As a result of the evaluation, a specific allocation and, subsequently, charge-offs have been taken as appropriate. As of December 31, 2016, there were no charge-offs associated with troubled debt restructured loans while under a forbearance agreement. As of December 31, 2016, there were no defaulted troubled debt restructured loans, as all troubled debt restructured loans were current with respect to their associated forbearance agreements. There were also no defaults on troubled debt restructured loans within twelve months of restructure during 2016. One forbearance agreement was negotiated during 2008, eight forbearance agreements were negotiated during 2009, two were negotiated during 2013, one was negotiated during 2014, and three were negotiated during 2016. Mid Penn entered into forbearance agreements on all loans currently classified as troubled debt restructurings and all of these agreements have resulted in additional principal repayment. The terms of these forbearance agreements vary whereby principal payments have been decreased, interest rates have been reduced and/or the loan will be repaid as collateral is sold. There were ten loans modified in 2017 and three loans modified in 2016 that resulted in troubled debt restructurings. There were no loans modified in 2015 that resulted in troubled debt restructurings. The following table summarizes the loans whose terms have been modified resulting in troubled debt restructurings during the year ended December 31, 2017. (Dollars in thousands) Pre-Modification Post-Modification December 31, 2017 Number of Contracts Outstanding Recorded Investment Outstanding Recorded Investment Recorded Investment Commercial and industrial 1 $ 4,110 $ 4,460 $ 4,434 Commercial real estate 9 3,212 3,150 3,140 10 $ 7,322 $ 7,610 $ 7,574 The following table provides activity for the accretable yield of purchased impaired loans for the year ended December 31, 2017. (Dollars in thousands) Accretable yield, January 1, 2017 $ 67 Accretable yield amortized to interest income (23 ) Reclassification from nonaccretable difference (a) 23 Accretable yield, December 31, 2017 $ 67 (a) Reclassification from non-accretable difference represents an increase to the estimated cash flows to be collected on the underlying portfolio. The Bank has granted loans to certain of its executive officers, directors, and their related interests. The aggregate amount of these loans was $15,163,000 and $17,634,000 at December 31, 2017 and 2016, respectively. During 2017, $2,178,000 of new loans and advances were extended and repayments totaled $4,649,000. None of these loans were past due, in nonaccrual status, or restructured at December 31, 2017.

Bank Premises and Equipment

Bank Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Bank Premises and Equipment	(9) Bank Premises and Equipment At December 31, 2017 and 2016, bank premises and equipment are as follows: (Dollars in thousands) 2017 2016 Land $ 3,564 $ 2,315 Buildings 8,632 9,517 Furniture, fixtures, and equipment 8,262 8,184 Leasehold improvements 1,126 1,432 Construction in progress 4,467 89 Total cost 26,051 21,537 Less accumulated depreciation (9,883 ) (10,463 ) Net book value of bank premises and equipment 16,168 11,074 Assets held for sale - 1,894 Total bank premises and equipment $ 16,168 $ 12,968 There were no premises and equipment classified as held for sale as of December 31, 2017. As of December 31, 2016, assets held-for-sale consisted of three full service retail banking properties. These properties were transferred from land and buildings to assets held for sale during 2016 due to Mid Penn’s intent to sell them during January 2017. An impairment charge of $142,000 was recorded on one of the properties at December 31, 2016 and included as a separate component in noninterest expense on the Consolidated Statements of Income. On January 20, 2017, Mid Penn consummated the sale of the three properties for an aggregate purchase price of $2,240,000, which exceeds Mid Penn’s combined carrying value by approximately $346,000. Two of the properties are being leased back by Mid Penn for a period of at least 15 years, and the respective gains on the sales of those properties will be recognized over the life of the leases. As of December 31, 2017, construction in process included (i) a commercial building and related improvements in Harrisburg, (ii) two vacant and undeveloped lots adjacent to the commercial building; and (iii) land, building, and improvements related to a newly constructed branch in Halifax, PA. The commercial building and adjacent lots in Harrisburg, PA were being renovated as of December 31, 2017 to serve as an administrative center for the Company, replacing two administrative offices which were previously leased. The renovations were substantially completed in February 2018, and Mid Penn employees took occupancy at that time. The new full-service office in Halifax, PA opened on January 8, 2018. Depreciation expense was $1,464,000 in 2017, $1,658,000 in 2016, and $1,485,000 in 2015. Operating Leases: As of December 31, 2017, Mid Penn was obligated to utilize certain premises under certain non-cancelable operating leases, which expire at various dates through the year ending December 31, 2035. Many of these leases contain renewal options and certain leases contain escalation clauses calling for rentals to be adjusted for increased real estate taxes and other operating expenses, or proportionately adjusted for increases in consumer or other price indices. Four of Mid Penn’s operating leases are with related parties. The rental expense paid to related parties was $352,000 in 2017, $348,000 in 2016, and $279,000 in 2015. The future minimum payments to related parties are $328,000 (2018), $304,000 (2019), $305,000 (2020), $213,000 (2021), $182,000 (2022) and $1,937,000 thereafter. In 2016, Mid Penn entered into two subleasing agreements with escalation clauses to two unrelated parties. The first sublease agreement began on April 1, 2016, while the second sublease began on July 1, 2016. Both subleases end on March 31, 2021. The following summary reflects the future minimum rental payments by year under Mid Penn’s operating leases as of December 31, 2017, including a breakdown of the sublease rental income and future minimum payments owed to related parties. (Dollars in thousands) Lease Obligation Sublease Rental Income Net Rental Expense 2018 1,171 79 1,092 2019 975 81 894 2020 790 81 709 2021 617 20 597 2022 564 — 564 thereafter 5,113 — 5,113 $ 9,230 $ 261 $ 8,969 Rental expense in connection with leases was $1,087,000 in 2017, $716,000 in 2016, and $627,000 in 2015.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposits	(10) Deposits At December 31, 2017 and 2016, time deposits amounted to $201,623,000 and $182,595,000, respectively. Interest expense on certificates of deposit amounted to $2,570,000, $2,156,000, and $1,920,000 for the years ended December 31, 2017, 2016 and 2015, respectively. The aggregate amount of demand deposit overdrafts that were reclassified as loans were $136,000 at December 31, 2017, compared to $285,000 as of December 31, 2016. Time deposits at December 31, 2017, mature as follows: (Dollars in thousands) Time Deposits Less than $250,000 $250,000 or more Maturing in 2018 $ 74,304 $ 29,736 Maturing in 2019 38,810 4,811 Maturing in 2020 24,380 885 Maturing in 2021 16,987 309 Maturing in 2022 8,984 1,452 Maturing thereafter 965 — $ 164,430 $ 37,193 Brokered deposits included in the time deposit totals equaled $19,447,000 at December 31, 2017 and $13,567,000 at December 31, 2016. Deposits and other funds from related parties held by Mid Penn at December 31, 2017 and 2016 amounted to $20,262,000 and $19,279,000, respectively.

Short-term Borrowings

Short-term Borrowings	12 Months Ended
	Dec. 31, 2017
Short Term Borrowings [Abstract]
Short-term Borrowings	(11) Short-term Borrowings Short-term borrowings generally have original terms of less than thirty days. Mid Penn’s short-term borrowings totaled $34,611,000 at December 31, 2017 and consisted entirely of federal funds purchased with a rate of 1.54%. There were no short-term borrowings at December 31, 2016. The Bank also has short-term borrowing capacity from the FHLB up to the Bank’s unused borrowing capacity of $436,821,000 at December 31, 2017, upon satisfaction of any stock purchase requirements of the FHLB. The Bank also has unused overnight lines of credit with other correspondent banks amounting to $15,000,000 at December 31, 2017.

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2017
Maturities Of Long Term Debt [Abstract]
Long-term Debt	(12) Long-term Debt The Bank is a member of the FHLB and through its membership, the Bank can access a number of credit products, which are utilized to provide liquidity. As of December 31, 2017 and 2016, the Bank had long-term debt outstanding in the amount of $12,352,000 and $13,581,000, respectively, consisting of: (Dollars in thousands) At December 31, 2017 2016 Loans maturing in 2017 at a rate of 3.03% $ — $ 1,016 Loan maturing in 2019 at a rate of 1.87% 10,000 10,000 Loan maturing in 2026 at a rate of 4.80% 2,295 2,504 Loan maturing in 2027 at a rate of 6.71% 57 61 $ 12,352 $ 13,581 The aggregate principal amounts due on long-term debt subsequent to December 31, 2017 are $223,000 (2018), $10,235,000 (2019), $246,000 (2020), $258,000 (2021), $271,000 (2022)and $1,119,000 thereafter.

Subordinated Debt

Subordinated Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Subordinated Debt	(13) Subordinated Debt Subordinated Debt Issued December 2017 On December 19, 2017, Mid Penn entered into agreements with investors to purchase $10,000,000 aggregate principal amount of its Subordinated Notes due 2028 (the “2017 Notes”). The 2017 Notes are intended to be treated as Tier 2 capital for regulatory capital purposes. The offering closed in December 2017. The 2017 Notes will bear interest at a rate of 5.25% per year for the first five years and then float at the Wall Street Journal’s Prime Rate plus 0.50%, provided that the interest rate applicable to the outstanding principal balance will at no times be less than 5.0%. Interest will be payable semi-annually in arrears on January 15 and July 15 of each year, beginning on July 15, 2018, for the first five years after issuance and will be payable quarterly in arrears thereafter on January 15, April 15, July 15, and October 15. The 2017 Notes will mature on January 1, 2028 and are redeemable in whole or in part, without premium or penalty, at any time on or after December 21, 2022, and prior to January 1, 2028. Additionally, Mid Penn may redeem the 2017 Notes in whole at any time, or in part from time to time, upon at least 30 days’ notice if: (i) a change or prospective change in law occurs that could prevent Mid Penn from deducting interest payable on the 2017 Notes for U.S. federal income tax purposes; (ii) an event occurs that precludes the 2017 Notes from being recognized as Tier 2 capital for regulatory capital purposes; or (iii) Mid Penn becomes required to register as an investment company under the Investment Company Act of 1940, as amended. In the event of a redemption described in the previous sentence, Mid Penn will redeem the 2017 Notes at 100% of the principal amount of the 2017 Notes, plus accrued and unpaid interest thereon to but excluding the date of redemption. Holders of the 2017 Notes may not accelerate the maturity of the 2017 Notes, except upon the bankruptcy, insolvency, liquidation, receivership or similar event of Mid Penn or Mid Penn Bank, its principal banking subsidiary. As of December 31, 2017, related parties held $1,450,000 of the 2017 Notes. Subordinated Debt Issued December 2015 On December 9, 2015, Mid Penn sold $7,500,000 aggregate principal amount of its Subordinated Notes due 2025 (the “2015 Notes”). The 2015 Notes are treated as Tier 2 capital for regulatory capital purposes. The 2015 Notes bear interest at a rate of 5.15% per year for the first five years and then float at the Wall Street Journal’s Prime Rate plus 0.50%, provided that the interest rate applicable to the outstanding principal balance will at no times be less than 4.0%. Interest will be payable quarterly in arrears on January 1, April 1, July 1 and October 1 of each year, and began on January 1, 2016. The 2015 Notes will mature on December 9, 2025 and are redeemable in whole or in part, without premium or penalty, at any time on or after December 9, 2020, and prior to December 9, 2025. Additionally, Mid Penn may redeem the 2015 Notes in whole at any time, or in part from time to time, upon at least 30 days’ notice if: (i) a change or prospective change in law occurs that could prevent Mid Penn from deducting interest payable on the 2015 Notes for U.S. federal income tax purposes; (ii) an event occurs that precludes the 2015 Notes from being recognized as Tier 2 capital for regulatory capital purposes; or (iii) Mid Penn becomes required to register as an investment company under the Investment Company Act of 1940, as amended, in each case at 100% of the principal amount of the 2015 Notes, plus accrued and unpaid interest thereon to but excluding the date of redemption. Holders of the 2015 Notes may not accelerate the maturity of the 2015 Notes, except upon Mid Penn’s or Mid Penn Bank, its principal banking subsidiary’s, bankruptcy, insolvency, liquidation, receivership or similar event. As of December 31, 2017, related parties held $1,930,000 of the 2015 Notes.

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurement	(14) Fair Value Measurement 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. This guidance provides additional information on determining when the volume and level of activity for the asset or liability has significantly decreased. The guidance also includes information on identifying circumstances when a transaction may not be considered orderly. 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 the fair value measurement and disclosure guidance. This guidance 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 is 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. Inputs to valuation techniques refer to the assumptions that market participants would use in pricing the asset or liability. Inputs may be observable, meaning those that reflect the assumptions market participants would use in pricing the asset or liability developed based on market data obtained from independent sources, or unobservable, meaning those that reflect the reporting entity’s own belief about the assumptions market participants would use in pricing the asset or liability based upon the best information available in the circumstances. Fair value measurement and disclosure guidance establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows: Level 1 Inputs - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 Inputs - 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 Inputs - Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). A description of the valuation methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. There were no transfers of assets between fair value Level 1 and Level 2 for the years ended December 31, 2017 or 2016. The following tables illustrate the assets measured at fair value on a recurring basis segregated by hierarchy fair value levels: Fair value measurements at December 31, 2017 using: (Dollars in thousands) Total carrying value at Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Assets: December 31, 2017 (Level 1) (Level 2) (Level 3) U.S. Treasury and U.S. government agencies $ 38,730 $ — $ 38,730 $ — Mortgage-backed U.S. government agencies 25,831 — $ 25,831 — State and political subdivision obligations 27,043 — $ 27,043 — Corporate debt securities 1,005 — $ 1,005 — Equity securities 856 856 — — $ 93,465 $ 856 $ 92,609 $ — Fair value measurements at December 31, 2016 using: (Dollars in thousands) Total carrying value at Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Assets: December 31, 2016 (Level 1) (Level 2) (Level 3) U.S. Treasury and U.S. government agencies $ 47,012 $ 1,864 $ 45,148 $ — Mortgage-backed U.S. government agencies 25,619 — 25,619 — State and political subdivision obligations 58,838 — 58,838 — Corporate debt securities 1,000 — 1,000 — Equity securities 1,156 1,056 100 — $ 133,625 $ 2,920 $ 130,705 $ — Certain financial assets and financial liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis, but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). The following tables illustrate the assets measured at fair value on a nonrecurring basis segregated by hierarchy fair value levels. Fair value measurements at December 31, 2017 using: (Dollars in thousands) Total carrying value at Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Assets: December 31, 2017 (Level 1) (Level 2) (Level 3) Impaired Loans $ 6,090 $ — $ — $ 6,090 Foreclosed Assets Held for Sale — — — — Mortgage Servicing Rights 126 — — 126 Fair value measurements at December 31, 2016 using: (Dollars in thousands) Total carrying value at Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Assets: December 31, 2016 (Level 1) (Level 2) (Level 3) Impaired Loans $ 2,404 $ — $ — $ 2,404 Foreclosed Assets Held for Sale 135 — — 135 Mortgage Servicing Rights 144 — — 144 The following tables present additional quantitative information about assets measured at fair value on a nonrecurring basis and for which Mid Penn has utilized Level 3 inputs to determine the fair value. (Dollars in thousands) Quantitative Information about Level 3 Fair Value Measurements December 31, 2017 Fair Value Estimate Valuation Technique Unobservable Input Range Weighted Average Impaired Loans $ 6,090 Appraisal of collateral (a) Appraisal adjustments (b) 6% - 51% 28% Foreclosed Assets Held for Sale — Appraisal of collateral (a), (c) Appraisal adjustments (b) 0% - 0% 0% Mortgage Servicing Rights 126 Multiple of annual service fee Estimated prepayment speed based on rate and term 70% - 100% 98% (Dollars in thousands) Quantitative Information about Level 3 Fair Value Measurements December 31, 2016 Fair Value Estimate Valuation Technique Unobservable Input Range Weighted Average Impaired Loans $ 2,404 Appraisal of collateral (a) Appraisal adjustments (b) 11% - 70% 30% Foreclosed Assets Held for Sale 135 Appraisal of collateral (a), (c) Appraisal adjustments (b) 26% - 31% 27% Mortgage Servicing Rights 144 Multiple of annual service fee Estimated prepayment speed based on rate and term 70% - 100% 98% (a) Fair value is generally determined through independent 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 percent 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, or age of the appraisal. (c) Includes qualitative adjustments by management and estimated liquidation expenses. The following methodologies and assumptions were used to estimate the fair value of certain assets and liabilities: Cash and Cash Equivalents: The carrying value of cash and cash equivalents is considered to be a reasonable estimate of fair value. Interest-bearing Balances with other Financial Institutions: The estimate of fair value was determined by comparing the present value of quoted interest rates on like deposits with the weighted average yield and weighted average maturity of the balances. Securities Available for sale: The fair value of securities classified as available for sale is 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 relying on the securities’ relationship to other benchmark quoted prices. Impaired Loans (included in “Net Loans and Leases” in the following tables): Mid Penn’s rating system assumes any loans classified as substandard nonaccrual to be impaired, and most of these loans are considered collateral dependent; therefore, most of Mid Penn’s impaired loans, whether reporting a specific allocation or not, are considered collateral dependent. It is Mid Penn’s policy to obtain updated third party valuations on all impaired loans collateralized by real estate as soon as practically possible of the credit being classified as substandard nonaccrual. Prior to receipt of the updated real estate valuation Mid Penn will use any existing real estate valuation to determine any potential allowance issues; however, no allowance recommendation will be made until Mid Penn is in receipt of the updated valuation. In some instances Mid Penn is not holding real estate as collateral and is relying on business assets (personal property) for repayment. In these circumstances a collateral inspection is performed by Mid Penn personnel to determine an estimated value. The value is based on net book value, as provided by the financial statements, and discounted accordingly based on determinations made by management. Occasionally, Mid Penn will employ an outside service to provide a fair estimate of value based on auction sales or private sales. Management reviews the estimates of these third parties and discounts them accordingly based on management’s judgment, if deemed necessary. Mid Penn considers the estimates used in its impairment analysis to be Level 3 inputs. Mid Penn actively monitors the values of collateral on impaired loans. This monitoring may require the modification of collateral values over time or changing circumstances by some factor, either positive or negative, from the original values. All collateral values will be assessed by management at least every 12 months for possible revaluation by an independent third party. Loans: For variable-rate loans that reprice frequently and which entail no significant changes in credit risk, carrying values approximated fair value. The fair value of other loans are estimated by calculating the present value of the cash flow difference between the current rate and the market rate, for the average maturity, discounted quarterly at the market rate. Foreclosed Assets Held for Sale: Assets included in foreclosed assets held for sale are carried at fair value, less costs to sell, and accordingly is presented as measured on a non-recurring basis. Values are estimated using Level 3 inputs, based on appraisals that consider the sales prices of property in the proximate vicinity. Accrued Interest Receivable and Payable: The carrying amount of accrued interest receivable and payable approximates their fair values. Restricted Investment in Bank Stocks: The carrying amount of required and restricted investment in correspondent bank stock approximates fair value, and considers the limited marketability of such securities. Mortgage Servicing Rights: The fair value of servicing rights is based on the present value of estimated future cash flows on pools of mortgages stratified by rate and maturity date. Deposits: The fair value for demand deposits (e.g., interest and noninterest checking, savings, and money market deposit accounts) is by definition, equal to the amount payable on demand at the reporting date (i.e. their carrying amounts). Fair value for fixed-rate certificates of deposit was estimated using a discounted cash flow calculation by combining all fixed-rate certificates into a pool with a weighted average yield and a weighted average maturity for the pool and comparing the pool with interest rates currently being offered on a similar maturity. Short-term Borrowings: Because of time to maturity, the estimated fair value of short-term borrowings approximates the book value. Long-term Borrowings and Subordinated Debt: The estimated fair values of long-term borrowings and subordinated debt were determined using discounted cash flow analysis, based on currently available borrowing rates for similar types of borrowing arrangements. Commitments to Extend Credit and Letters of Credit: The fair value of commitments to extend credit is estimated using the fees currently charged to enter into similar agreements, taking into account market interest rates, the remaining terms and present credit worthiness of the counterparties. The fair value of guarantees and letters of credit is based on fees currently charged for similar agreements. The following table summarizes the carrying value and fair value of financial instruments at December 31, 2017 and 2016. (Dollars in thousands) December 31, 2017 December 31, 2016 Carrying Fair Carrying Fair Value Value Value Value Financial assets: Cash and cash equivalents $ 23,514 $ 23,514 $ 45,973 $ 45,973 Available for sale investment securities 93,465 93,465 133,625 133,625 Held to maturity investment securities 101,356 100,483 — — Net loans and leases 902,798 917,081 806,741 824,293 Restricted investment in bank stocks 4,384 4,384 2,443 2,443 Accrued interest receivable 4,564 4,564 3,928 3,928 Mortgage servicing rights 126 126 144 144 Financial liabilities: Deposits $ 1,023,568 $ 1,026,830 $ 935,373 $ 935,075 Short-term borrowings 34,611 34,611 — — Long-term debt 12,352 11,692 13,581 13,614 Subordinated debt 17,338 17,358 7,414 7,534 Accrued interest payable 645 645 515 515 Off-balance sheet financial instruments: Commitments to extend credit $ — $ — $ — $ — Financial standby letters of credit — — — — The following presents the carrying amount, fair value, and placement in the fair value hierarchy of Mid Penn’s financial instruments as of December 31, 2017 and 2016. Carrying values approximate fair values for cash and cash equivalents, interest-bearing time balances with other financial institutions, restricted investment in bank stocks, accrued interest receivable and payable, and short-term borrowings. Other than cash and cash equivalents, which are considered Level 1 Inputs, these instruments are Level 2 Inputs. The following tables exclude financial instruments for which the placement in the fair value hierarchy has been disclosed elsewhere or for which the carrying amount approximates fair value. Fair Value Measurements (Dollars in thousands) Quoted Prices Significant in Active Markets Other Significant for Identical Assets Observable Unobservable Carrying Fair or Liabilities Inputs Inputs December 31, 2017 Amount Value (Level 1) (Level 2) (Level 3) Financial instruments - assets Net loans and leases $ 902,798 $ 917,081 $ — $ — $ 917,081 Financial instruments - liabilities Deposits $ 1,023,568 $ 1,026,830 $ — $ 1,026,830 $ — Long-term debt 12,352 11,692 — 11,692 — Subordinated debt 17,338 17,358 — — 17,358 Fair Value Measurements (Dollars in thousands) Quoted Prices Significant in Active Markets Other Significant for Identical Observable Unobservable Carrying Fair or Liabilities Inputs Inputs December 31, 2016 Amount Value (Level 1) (Level 2) (Level 3) Financial instruments - assets Net loans and leases $ 806,741 $ 824,293 $ — $ — $ 824,293 Financial instruments - liabilities Deposits $ 935,373 $ 935,075 $ — $ 935,075 $ — Long-term debt 13,581 13,614 — 13,614 — Subordinated debt 7,414 7,534 — — 7,534

Postretirement Benefit Plans

Postretirement Benefit Plans	12 Months Ended
	Dec. 31, 2017
Defined Benefit Pension Plans And Defined Benefit Postretirement Plans Disclosure [Abstract]
Postretirement Benefit Plans	(15) Postretirement Benefit Plans Mid Penn has an unfunded noncontributory defined benefit plan for directors, which provides defined benefits based on the respective director’s years of service. Mid Penn also has other postretirement healthcare and life insurance benefit plans, which are noncontributory, covering certain full-time employees. The significant aspects of each of these plans are as follows: (a) Health Insurance Full-time employees who had at least 10 years of service as of January 1, 2008 and who retire at age 55 or later, after completion of at least 20 years of service, are eligible for medical benefits. Employees who retired prior to December 31, 2015 may elect the least expensive single coverage in the employer’s group medical plan. If the retiree becomes eligible for Medicare during the five year duration of coverage, the Bank will pay, at its discretion, premiums for single 65-special coverage or similar supplemental coverage. For those employees who retired between September 18, 2015 and December 31, 2015, the Bank will only pay up to $5,000 towards such medical coverage. Employees who retired after December 31, 2015 may not participate in the employer’s group medical plan. Instead, the Bank will reimburse the retiree for up to $5,000 in medical costs. (b) Life Insurance Full-time employees who had at least ten years of service as of January 1, 2008 and retire with the Bank after age 55 and at least 20 years of service are eligible for term life insurance coverage. The insurance amount will be $50,000 until age 65. After age 65, the insurance amount will decrease by $5,000 per year until age 74. Thereafter, the insurance amount will be $5,000. (c) Directors’ Retirement Plan Mid Penn has an unfunded defined benefit retirement plan for directors with benefits based on years of service. The adoption of this plan generated unrecognized prior service cost of $274,000, which is being amortized over the expected future years of service of active directors. The unamortized balance at December 31, 2017, was $22,000. The accrued benefit liability and related income statement impacts of the postretirement healthcare and life insurance benefit plans, as well as the Director’s retirement plan, are detailed in the tables below. Health and Life The following tables provide a reconciliation of the changes in the plan’s health and life insurance benefit obligations and fair value of plan assets for the years ended December 31, 2017 and 2016, and a statement of the funded status at December 31, 2017 and 2016. (Dollars in thousands) December 31, Change in benefit obligations: 2017 2016 Benefit obligations, January 1 $ 540 $ 572 Service cost 4 4 Interest cost 20 23 Change in experience (11 ) 2 Change in assumptions 20 13 Change due to plan amendment — — Benefit payments (65 ) (74 ) Benefit obligations, December 31 $ 508 $ 540 Change in fair value of plan assets: Fair value of plan assets, January 1 $ — $ — Employer contributions 65 74 Benefit payments (65 ) (74 ) Fair value of plan assets, December 31 $ — $ — Funded status at year end $ (508 ) $ (540 ) Mid Penn has capped the benefit to future retirees under its post-retirement health benefit plan. Employees who had achieved ten years of service as of January 1, 2008 and subsequently retire after at least 20 years of service are eligible for reimbursement of major medical insurance premiums up to $5,000, if the employee has not yet reached age 65. Upon becoming eligible for Medicare, Mid Penn will reimburse up to $5,000 in premiums for Medicare Advantage or a similar supplemental coverage. The maximum reimbursement period will not exceed five years regardless of retirement age and will end upon the participant obtaining other employment where major medical coverage is available or the participant’s death. The amount recognized in the consolidated balance sheets at December 31, 2017 and 2016, is as follows: (Dollars in thousands) 2017 2016 Accrued benefit liability $ 508 $ 540 The amounts recognized in accumulated other comprehensive loss consist of: (Dollars in thousands) December 31, 2017 2016 Net gain, pretax $ (22 ) $ (31 ) Net prior service cost, pretax (174 ) (209 ) The accumulated benefit obligation for health and life insurance plans was $508,000 and $540,000 at December 31, 2017 and 2016, respectively. There will be $25,000 in estimated prior service costs amortized from accumulated other comprehensive income into net periodic benefit cost during 2018. The components of net periodic postretirement benefit (income) cost for 2017, 2016 and 2015 are as follows: (Dollars in thousands) 2017 2016 2015 Service cost $ 4 $ 4 $ 13 Interest cost 20 23 32 Amortization of prior service cost (35 ) (35 ) - Net periodic postretirement benefit (income) cost $ (11 ) $ (8 ) $ 45 Assumptions used in the measurement of Mid Penn’s benefit obligations at December 31, 2017 and 2016 are as follows: Weighted-average assumptions: 2017 2016 Discount rate 3.50 % 4.00 % Rate of compensation increase 2.50 % 3.00 % Assumptions used in the measurement of Mid Penn’s net periodic benefit cost for the years ended December 31, 2017, 2016 and 2015 are as follows: Weighted-average assumptions: 2017 2016 2015 Discount rate 4.00 % 4.25 % 4.00 % Rate of compensation increase 3.00 % 3.25 % 3.00 % Assumed health care cost trend rates at December 31, 2017, 2016 and 2015 are as follows: 2017 2016 2015 Health care cost trend rate assumed for next year 6.00 % 6.00 % 5.50 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 5.40 % 5.50 % 5.50 % Year that the rate reaches the ultimate trend rate 2024 2018 2016 Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plans. At December 31, 2017, a one-percentage-point change in assumed health care cost trend rates would have the following effects: (Dollars in thousands) One-Percentage Point Increase Decrease Effect on total of service and interest cost $ — $ 2 Effect on accumulated postretirement benefit obligation 3 4 Mid Penn expects to contribute $60,000 to its life and health benefit plans in 2018. The following table shows the estimated benefit payments for future periods. (Dollars in thousands) 1/1/2018 to 12/31/2018 $ 60 1/1/2019 to 12/31/2019 61 1/1/2020 to 12/31/2020 55 1/1/2021 to 12/31/2021 31 1/1/2022 to 12/31/2022 32 1/1/2023 to 12/31/2027 160 Retirement Plan The following tables provide a reconciliation of the changes in the directors’ defined benefit plan’s benefit obligations and fair value of plan assets for the years ended December 31, 2017 and 2016, and a statement of the status at December 31, 2017 and 2016. This Plan is unfunded. (Dollars in thousands) December 31, Change in benefit obligations: 2017 2016 Benefit obligations, January 1 $ 1,122 $ 1,150 Service cost 35 34 Interest cost 43 46 Actuarial gain (loss) 6 (13 ) Change in assumptions 2 (4 ) Benefit payments (92 ) (91 ) Benefit obligations, December 31 $ 1,116 $ 1,122 Change in fair value of plan assets: Fair value of plan assets, January 1 $ — $ — Employer contributions 92 91 Benefit payments (92 ) (91 ) Fair value of plan assets, December 31 $ — $ — Funded status at year end $ (1,116 ) $ (1,122 ) Amounts recognized in the consolidated balance sheet at December 31, 2017 and 2016 are as follows: (Dollars in thousands) 2017 2016 Accrued benefit liability $ 1,116 $ 1,122 Amounts recognized in accumulated other comprehensive loss consist of: (Dollars in thousands) December 31, 2017 2016 Net prior service cost, pretax $ 22 $ 43 Net loss, pretax 67 60 The accumulated benefit obligation for the retirement plan was $1,116,000 at December 31, 2017 and $1,122,000 at December 31, 2016. The estimated prior service costs that will be amortized from accumulated other comprehensive loss into net periodic benefit cost during 2018 is $22,000. The components of net periodic retirement cost for 2017, 2016 and 2015 are as follows: (Dollars in thousands) 2017 2016 2015 Service cost $ 35 $ 34 $ 33 Interest cost 43 46 45 Amortization of prior-service cost 22 22 22 Net periodic retirement cost $ 100 $ 102 $ 100 Assumptions used in the measurement of Mid Penn’s benefit obligations at December 31, 2017 and 2016 are as follows: Weighted-average assumptions: 2017 2016 Discount rate 3.50 % 4.00 % Change in consumer price index 1.50 % 2.00 % Assumptions used in the measurement of Mid Penn’s net periodic benefit cost for the years ended December 31, 2017, 2016 and 2015 are as follows: Weighted-average assumptions: 2017 2016 2015 Discount rate 4.00 % 4.25 % 4.00 % Change in consumer price index 2.00 % 2.25 % 2.25 % Mid Penn expects to contribute $95,000 to its retirement plan in 2018. The following table shows the estimated benefit payments for future periods. (Dollars in thousands) 1/1/2018 to 12/31/2018 $ 95 1/1/2019 to 12/31/2019 95 1/1/2020 to 12/31/2020 96 1/1/2021 to 12/31/2021 107 1/1/2022 to 12/31/2022 104 1/1/2023 to 12/31/2027 413 The Bank is the owner and beneficiary of insurance policies on the lives of certain officers and directors, which informally fund the retirement plan obligation. The aggregate cash surrender value of these policies was $3,905,000 and $3,834,000 at December 31, 2017 and 2016, respectively.

Other Benefit Plans

Other Benefit Plans	12 Months Ended
	Dec. 31, 2017
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Other Benefit Plans	(16) Other Benefit Plans (a) 401(k) Plan The Bank has a 401(k) plan that covers substantially all full-time employees. The plan allows employees to contribute a portion of their salaries and wages to the plan and provides for the Bank to match a portion of employee-elected salary deferrals, subject to certain percentage maximums of their salaries and wages. The Bank’s contribution to the 401(k) Plan was $383,000, $362,000, and $321,000 for the years ending December 31, 2017, 2016, and 2015, respectively. (b) Defined-Contribution Plan The Bank has a funded contributory defined-contribution plan covering substantially all employees. The Bank did not contribute to the plan in 2017, 2016, or 2015. (c) Deferred Compensation Plans The Bank has an executive deferred compensation plan, which allows executive officers to defer compensation for a specified period in order to provide future retirement income. The only participant in the Plan is a former executive officer. The Bank accrued a liability for the plan of approximately $125,000 at December 31, 2017 and $143,000 at December 31, 2016. The expense related to the plan was $5,000 in 2017, $6,000 in 2016, and $9,000 in 2015. The Bank also has a directors’ deferred compensation plan, which allows directors to defer receipt of director fees for a specified period in order to provide future retirement income. At December 31, 2017 and 2016, the Bank accrued a liability of $683,000 and $606,000, respectively, for this plan. The expense related to the plan was $25,000 in 2017, $21,000 in 2016, and $17,000 in 2015. (d) Salary Continuation Agreement The Bank maintains a Salary Continuation Agreement (“Agreement”) for a former executive officer. The Agreement provides the former executive officer with a fixed annual benefit. The benefit is payable beginning at age 65 for a period of 15 years. At December 31, 2017 and 2016, the Bank accrued a liability of approximately $246,000 and $254,000, respectively, for the Agreement. The expense related to the Agreement was $17,000 for 2017, $17,000 for 2016, and $16,000 for 2015. The Bank is the owner and beneficiary of an insurance policy on the life of the participating former executive officer, which supports the funding of the benefit obligation. The aggregate cash surrender value of this policy was approximately $1,317,000 and $1,284,000 at December 31, 2017 and 2016, respectively. (e) Split Dollar Life Insurance Arrangements At December 31, 2017 and 2016, the Bank had Split Dollar Life Insurance arrangements with two former executives for which the aggregate collateral assignment and cash surrender values are approximately $1,375,000 and $1,360,000, respectively. Mid Penn also acquired Phoenix’s Split Dollar Life Insurance arrangements in 2015 on select employees, which had aggregate cash surrender value of $3,924,000 at December 31, 2017 and $3,838,000 at December 31, 2016. (f) Employee Stock Purchase Plan Mid Penn has an Employee Stock Purchase Plan (“ESPP”) in which all employees are eligible to participate. The plan allows employees to use a portion of their salaries and wages to purchase common shares of Mid Penn stock at the market value of shares at the end of each calendar quarter. 2017 2016 2015 ESPP shares purchased 3,578 4,465 4,162 Average purchase price per share $ 29.027 $ 18.520 $ 15.865 (g) Director Stock Purchase Plan On May 24, 2017, the Board of Directors of Mid Penn approved the Director Stock Purchase Plan (“DSPP”). The purpose of the Plan is to provide non-employee directors of Mid Penn with a convenient means to purchase Corporation common stock at fair market value on the last day of each calendar quarter. The plan was effective beginning July 1, 2017. Participants purchased 1,345 shares at an average purchase price per share of $31.136 during the year ended December 31, 2017.

Federal Income Taxes

Federal Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal Income Taxes	(17) Federal Income Taxes The following temporary differences gave rise to the net deferred tax asset at December 31, 2017 and 2016. (Dollars in thousands) 2017 2016 Deferred tax assets: Allowance for loan and lease losses $ 1,597 $ 2,442 Loan fees 105 82 Deferred compensation 221 341 Benefit plans 320 565 Unrealized loss on securities 574 1,504 Nonaccrual interest — 955 Business combination adjustments 358 720 Sale/leaseback adjustment 72 — Other 108 177 3,355 6,786 Deferred tax liabilities: Depreciation (619 ) (1,175 ) Bond accretion (9 ) (117 ) Goodwill and intangibles (329 ) (500 ) Prepaid expenses (333 ) (312 ) Business combination adjustments (176 ) (367 ) Other (1 ) (29 ) (1,467 ) (2,500 ) Deferred tax asset, net $ 1,888 $ 4,286 In assessing the realizability of federal or state deferred tax assets, management considers whether it is more likely than not some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and prudent, feasible and permissible as well as available tax planning strategies in making this assessment. Based on the level of historical taxable income and projections for future taxable income over the periods in which the deferred tax assets are deductible, management believes it is more likely than not that Mid Penn will realize the benefits of these deferred tax assets. On December 22, 2017, the Tax Cuts and Jobs Act was signed into law reducing the federal tax rate to 21% beginning on January 1, 2018. The revaluation of net deferred tax assets as of December 22, 2017 resulted in $1,169,000 of additional tax expense on the date of enactment included in deferred expense in the tables below. The provision for income taxes consists of the following: (Dollars in thousands) 2017 2016 2015 Current expense $ 2,672 $ 2,613 $ 647 Deferred expense (benefit) 1,828 (336 ) 997 Total provision for income taxes $ 4,500 $ 2,277 $ 1,644 A reconciliation of income tax at the statutory rate of 34% to Mid Penn's effective rate is as follows: (Dollars in thousands) 2017 2016 2015 Provision at the expected statutory rate $ 3,940 $ 3,428 $ 2,779 Effect of tax-exempt income (668 ) (1,089 ) (1,105 ) Effect of investment in life insurance (89 ) (90 ) (91 ) Nondeductible interest 30 41 37 Nondeductible merger and acquisition expense 191 — 34 Rate change adjustment 1,169 — — Other items (73 ) (13 ) (10 ) Provision for income taxes $ 4,500 $ 2,277 $ 1,644 Mid Penn has no unrecognized tax benefits that, if recognized, would favorably affect the effective income tax rate in future periods. Mid Penn does not expect the total amount of unrecognized tax benefits to significantly increase or decrease in the next twelve months. No amounts for interest and penalties were recorded in income tax expense in the consolidated statement of income for the years ended December 31, 2017, 2016, or 2015. There were no amounts accrued for interest and penalties at December 31, 2017 or 2016. Mid Penn and its subsidiaries are subject to U.S. federal income tax and income tax for the state of Pennsylvania. With limited exceptions, Mid Penn is no longer subject to examination by taxing authorities for years before 2014.

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Regulatory Matters	(18) Regulatory Matters Mid Penn Bancorp, Inc., is a bank holding company and, as such, chooses to maintain a well-capitalized status in its bank subsidiary. Quantitative measures established by regulation to ensure capital adequacy require Mid Penn to maintain minimum amounts and ratios (set forth below) of Tier 1 Capital to average assets and of Total Capital (as defined in the regulations) to risk-weighted assets. As of December 31, 2017 and December 31, 2016, Mid Penn met all capital adequacy requirements to which the Bank is subject, and the Bank is considered “well-capitalized”. However, future changes in regulations could increase capital requirements and may have an adverse effect on capital resources. The federal banking agencies have substantially amended the regulatory risk-based capital rules applicable to Mid Penn. The amendments implemented the Basel III regulatory capital reforms and changes required by the Dodd-Frank Act. The amended rules included new minimum risk-based capital and leverage ratios, which became effective in January 2015, with certain requirements to be phased in beginning in 2016, and refined the definition of what constitutes "capital" for purposes of calculating those ratios. The new minimum capital level requirements applicable to Mid Penn include: (i) a new common equity Tier I capital ratio of 4.5%; (ii) a Tier I capital ratio of 6.0% (increased from 4.0 %); (iii) a Total Capital ratio of 8.0% (unchanged from current rules); and (iv) a Tier I leverage ratio of 4.0% for all institutions. The amended rules also establish a "capital conservation buffer" of 2.5% above the new regulatory minimum capital ratios, and would result in the following minimum ratios: (i) a common equity Tier I capital ratio of 7.0%; (ii) a Tier I capital ratio of 8.5%; and (iii) a Total Capital ratio of 10.5%. The new capital conservation buffer requirement was phased in beginning in January 2016 at 0.625% of risk-weighted assets and will increase each year until fully implemented in January 2019. An institution will be subject to limitations on paying dividends, engaging in share repurchases, and paying discretionary bonuses if its capital level falls below the buffer amount. These limitations will establish a maximum percentage of eligible retained income that could be utilized for such actions. Certain restrictions exist regarding the ability of the Bank to transfer funds to the Corporation in the form of cash dividends, loans, or advances. The amount of dividends that may be paid in any calendar year is limited to the current year’s net profits, combined with the retained net profits of the preceding two years. At December 31, 2017, $5,259,000 of undistributed earnings of the Bank included in the consolidated shareholders’ equity was available for distribution to the Corporation as dividends without prior regulatory approval, subject to regulatory capital requirements below. Mid Penn maintained the following regulatory capital levels, leverage ratios, and risk-based capital ratios as of December 31, 2017, and December 31, 2016, as follows: (Dollars in thousands) Capital Adequacy To Well-Capitalized Under Prompt Minimum Capital Corrective Actual Required (1) Action Provisions Amount Ratio Amount Ratio Amount Ratio Corporation As of December 31, 2017 Tier 1 Capital (to Average Assets) $ 74,417 6.5 % $ 45,857 4.00 % $ N/A N/A Common Equity Tier 1 Capital (to Risk Weighted Assets) 74,417 8.4 % 50,661 5.75 % N/A N/A Tier 1 Capital (to Risk Weighted Assets) 74,417 8.4 % 63,877 7.25 % N/A N/A Total Capital (to Risk Weighted Assets) 99,466 11.3 % 81,498 9.25 % N/A N/A Bank As of December 31, 2017 Tier 1 Capital (to Average Assets) $ 88,294 7.7 % $ 45,846 4.00 % $ 57,308 5.0 % Common Equity Tier 1 Capital (to Risk Weighted Assets) 88,294 10.0 % 50,661 5.75 % 57,269 6.5 % Tier 1 Capital (to Risk Weighted Assets) 88,294 10.0 % 63,877 7.25 % 70,485 8.0 % Total Capital (to Risk Weighted Assets) 96,005 10.9 % 81,498 9.25 % 88,106 10.0 % Corporation As of December 31, 2016 Tier 1 Capital (to Average Assets) $ 70,431 6.8 % $ 41,595 4.00 % $ N/A N/A Common Equity Tier 1 Capital (to Risk Weighted Assets) 70,431 9.1 % 39,641 5.125 % N/A N/A Tier 1 Capital (to Risk Weighted Assets) 70,431 9.1 % 51,244 6.625 % N/A N/A Total Capital (to Risk Weighted Assets) 85,148 11.0 % 66,714 8.625 % N/A N/A Bank As of December 31, 2016 Tier 1 Capital (to Average Assets) $ 77,026 7.4 % $ 41,568 4.00 % $ 51,960 5.0 % Common Equity Tier 1 Capital (to Risk Weighted Assets) 77,026 10.0 % 39,611 5.125 % 50,239 6.5 % Tier 1 Capital (to Risk Weighted Assets) 77,026 10.0 % 51,205 6.625 % 61,832 8.0 % Total Capital (to Risk Weighted Assets) 84,329 10.9 % 66,663 8.625 % 77,291 10.0 % (1) Minimum amounts and ratios as of December 31, 2017 include the second year phase in of the capital conservation buffer of 1.25 percent required by the Basel III framework. At December 31, 2016, the minimum amounts and ratios included the first year phase in of the capital conservation buffer of 0.625 percent required by the Basel III framework.

Concentration of Risk and Off-B

Concentration of Risk and Off-Balance Sheet Risk	12 Months Ended
	Dec. 31, 2017
Concentration Risks Types No Concentration Percentage [Abstract]
Concentration Risk and Off-Balance Sheet Risk	(19) Concentration of Risk and Off-Balance Sheet Risk The Bank is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. Those instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated balance sheets. The Bank evaluates each customer's creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Bank upon extension of credit, is based on management's credit evaluation of the borrower. Collateral held varies but may include accounts receivable, inventory, property, plant, and equipment, and income-producing commercial properties. The Bank's exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit and standby letters of credit written is represented by the contractual amount of those instruments. The Bank uses the same credit policies in making commitments and conditional obligations as it does for direct, funded loans. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Standby letters of credit are conditional commitments issued by the Bank to guarantee the performance of a customer to a third party. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. The term of these standby letters of credit is generally one year or less. The amount of the liability as of December 31, 2017 and 2016 for guarantees under letters of credit issued is not material. As of December 31, 2017, commitments to extend credit amounted to $199,240,000 and standby letters of credit amounted to $20,496,000. As of December 31, 2016, commitments to extend credit amounted to $201,749,000 and standby letters of credit amounted to $14,000,000. Additionally, Mid Penn has sold loans to the FHLB as part of its Mortgage Partnership Finance Program (“Program). Under the terms of the Program, there is limited recourse back to Mid Penn for loans that do not perform in accordance with the terms of the loan agreement. Each loan that is sold under the Program is “credit enhanced” such that the individual loan’s rating is raised to “BBB”, as determined by the FHLB. The Program can be terminated by either the FHLB or Mid Penn, without cause, by giving notice to the other party. The FHLB has no obligation to commit to purchase any mortgage through, or from, Mid Penn. The total balance of loans sold under the Program was $7,314,000 and $9,206,000 for the years ended December 31, 2017 and 2016. Significant concentration of credit risk may occur when obligations of parties engaged in similar activities occur and accumulate in significant amounts. In analyzing the Bank's exposure to significant concentration of credit risk, management set a parameter of 10% or more of the Bank's total net loans outstanding as the threshold in determining whether the obligations of the same or affiliated parties would be classified as significant concentration of credit risk. Concentrations by industry, product line, type of collateral, etc., are also considered. U.S. Treasury securities, obligations of U.S. government agencies and corporations, and any assets collateralized by the same were excluded. As of December 31, 2017, commercial real estate financing was the only similar activity that met the requirements to be classified as a significant concentration of credit risk. However, there is a geographical concentration in that most of the Bank's business activity is with customers located in Central Pennsylvania, specifically within the Bank's trading area made up of Cumberland, Dauphin, Lancaster, Luzerne, Northumberland, and Schuylkill Counties. The Bank's highest concentrations of credit within the loan portfolio is in commercial real estate financing (51.1 %) as of December 31, 2017.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Contingencies	(20) Contingencies Litigation: Mid Penn is subject to lawsuits and claims arising out of its normal conduct of business. In the opinion of management, after consultation with legal counsel, the ultimate disposition of these matters is not expected to have a material adverse effect on the consolidated financial condition of Mid Penn.

Common Stock

Common Stock	12 Months Ended
	Dec. 31, 2017
Common Stock Number Of Shares Par Value And Other Disclosures [Abstract]
Common Stock	(21) Common Stock Dividend Reinvestment Plan Under Mid Penn’s amended and restated dividend reinvestment plan (“DRIP”), 330,750 shares of Mid Penn’s authorized but unissued common stock are reserved for issuance. The DRIP also allows for voluntary cash payments, within specified limits, to be used for the purchase of additional shares. Restricted Stock Plan On June 25, 2014, the 2014 Restricted Stock Plan was registered under which awards shall not exceed, in the aggregate, 100,000 shares of common stock. The Plan was established for employees and directors of Mid Penn and the Bank, selected by the Compensation Committee of the Board of Directors, to advance the best interest of Mid Penn and its shareholders. The plan provides those persons who have a responsibility for its growth with additional incentives by allowing them to acquire an ownership interest in Mid Penn and thereby encouraging them to contribute to the success of the company. As of December 31, 2017, 26,955 shares have been granted under the Plan. During 2017, Mid Penn granted 10,440 restricted shares, 6,040 of which were granted to employees while 4,400 were granted to directors. Mid Penn granted 7,540 restricted shares to employees in 2016 and 5,475 restricted shares to employees in 2015. In 2016, 470 of the granted shares were forfeited to Mid Penn due to the termination of employment of a plan participant. Share-based compensation expense relating to restricted stock is recognized on a straight-line basis over the vesting periods of the awards and is a component of salaries and benefits expense. Restricted shares granted to employees vest in equal amounts on the anniversary of the grant date over a four year vesting period. Restricted shares granted to directors have a twelve month vesting period. The following table presents compensation expense and related tax benefits for restricted stock awards recognized on the consolidated statement of income. (Dollars in thousands) 2017 2016 2015 Compensation expense $ 145 $ 53 $ 28 Tax benefit (49 ) (18 ) (10 ) Net income effect $ 96 $ 35 $ 18 At December 31, 2017, there was $440,000 of unrecognized compensation cost related to all non-vested share-based compensation awards. This cost is expected to be recognized through July 2021. Mid Penn recognizes the impact of forfeitures as of the forfeiture date. The following table presents information regarding the non-vested restricted stock for the year ended December 31, 2017. Shares Weighted-Average Grant Date Fair Value Non-vested at January 1, 2017 13,055 $ 17.66 Vested (3,996 ) 17.38 Cancelled — — Granted 10,440 26.65 Non-vested at December 31, 2017 19,499 22.54

Preferred Stock

Preferred Stock	12 Months Ended
	Dec. 31, 2017
Class Of Stock Disclosures [Abstract]
Preferred Stock	(22) Preferred Stock Series B Preferred Stock Between September 26, 2012 and January 3, 2013, Mid Penn issued, via a private placement, 5,000 shares of its 7% Non-Cumulative Non-Voting Non-Convertible Perpetual Preferred Stock, Series B Preferred Stock, resulting in total gross proceeds of $5,000,000. On December 9, 2015, Mid Penn, using a portion of the proceeds from the offering of the 2015 Notes, redeemed all of its issued and outstanding shares of Series B Preferred Stock at a price equal to $1,024.67 per share, which is equal to $1,020 per share plus declared but unpaid dividends on December 9, 2015, for a total redemption price of $5,123,000. Small Business Lending Fund Preferred Shares On March 1, 2015, Mid Penn assumed all of the issued and outstanding shares of Phoenix with respect to 1,750 shares of Phoenix’s preferred stock issued to the Treasury in connection with the Small Business Lending Fund and issued 1,750 shares of its own SBLF Preferred Shares that had a $1,000 liquidation preference per share, to the Treasury. The SBLF Preferred Shares qualified as Tier 1 Capital and had terms and conditions identical to those shares of preferred stock issued by Phoenix to the Treasury. Mid Penn paid noncumulative dividends payable quarterly on January 1, April 1, July 1, and October 1. The dividend rate was 1.00% per annum for payment dates up to January 19, 2016. On December 15, 2015, Mid Penn, using a portion of the proceeds from the offering of the 2015 Notes, redeemed all of the outstanding shares of its SBLF Preferred Shares, which were held by the Treasury, for an aggregate redemption price of $1,754,000, including accrued but unpaid dividends.

Parent Company Statements

Parent Company Statements	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Parent Company Statements	(23) Parent Company Statements CONDENSED BALANCE SHEETS (Dollars in thousands) December 31, 2017 2016 ASSETS Cash and cash equivalents $ 4,686 $ 780 Equity investments — 545 Investment in subsidiaries 89,581 77,029 Other assets — 40 Total assets $ 94,267 $ 78,394 LIABILITIES AND SHAREHOLDERS' EQUITY Subordinated debt $ 17,338 $ 7,414 Other liabilities 1,226 513 Shareholders' equity 75,703 70,467 Total liabilities and shareholders' equity $ 94,267 $ 78,394 CONDENSED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (Dollars in thousands) For Years Ended December 31, 2017 2016 2015 Income Dividends from subsidiaries $ 9,657 $ 2,871 $ 5,662 Other income 19 33 19 Total Income 9,676 2,904 5,681 Expense Other expenses (1,899 ) (606 ) (695 ) Total Expense (1,899 ) (606 ) (695 ) Income before income tax and equity in undistributed (loss) earnings of subsidiaries 7,777 2,298 4,986 Equity in undistributed (loss) earnings of subsidiaries (1,136 ) 5,311 1,346 Income before income tax 6,641 7,609 6,332 Income tax benefit 448 195 196 Net income 7,089 7,804 6,528 Series B preferred stock dividends and redemption premium — — 473 Series C preferred stock dividends — — 17 Net income available to common shareholders $ 7,089 $ 7,804 $ 6,038 Comprehensive income $ 8,209 $ 3,139 $ 6,827 CONDENSED STATEMENTS OF CASH FLOWS (Dollars in thousands) For Years Ended December 31, 2017 2016 2015 CASH FLOWS FROM OPERATING ACTIVITIES Net income $ 7,089 $ 7,804 $ 6,528 Equity in undistributed loss (earnings) of subsidiaries 1,136 (5,311 ) (1,346 ) Decrease (increase) in other assets 240 59 (14 ) Increase (decrease) in other liabilities 626 457 (665 ) Net cash provided by operating activities 9,091 3,009 4,503 CASH FLOWS FROM INVESTING ACTIVITIES Net cash paid for acquisition — — (2,949 ) Proceeds from the sale of investment securities 618 — — Investment in subsidiary (12,600 ) — — Net cash used in investing activities (11,982 ) — (2,949 ) CASH FLOWS FROM FINANCING ACTIVITIES Dividends paid (3,264 ) (2,875 ) (2,175 ) Series B preferred stock redemption premium — — (100 ) Series B preferred stock redemption — — (5,000 ) Series C preferred stock redemption — — (1,750 ) Employee Stock Purchase Plan 104 82 66 Director Stock Purchase Plan 42 — — Deferred financing fees paid for subordinated debt issuance (85 ) — (85 ) Subordinated debt issuance 10,000 — 7,500 Net cash provided by (used in) financing activities 6,797 (2,793 ) (1,544 ) Net increase in cash and cash equivalents 3,906 216 10 Cash and cash equivalents, beginning of year 780 564 554 Cash and cash equivalents, end of year $ 4,686 $ 780 $ 564

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2017
New Accounting Pronouncement Or Change In Accounting Principle Retrospective Adjustments [Abstract]
Recent Accounting Pronouncements	(24) Recent Accounting Pronouncements ASU 2017-08 : The Financial Accounting Standards Board (“FASB”) issued ASU 2017-08, Premium Amortization on Purchased Callable Debt Securities. The ASU 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, but does not change the accounting for securities held at a discount. The ASU applies to callable debt securities with explicit, non-contingent 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, it applies to all premiums on callable debt securities, regardless of how they were generated. The ASU requires 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. It is effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those years. For all other entities, the amendments are effective for annual periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. 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. Mid Penn has early adopted this standard, and the financial statements as of and for the year ended December 31, 2017 reflect the impact of premium amortization on callable debt securities to the earliest call date. The adoption of this ASU did not have a material impact on Mid Penn’s consolidated financial statements. ASU 2017-07 : The FASB issued ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. The ASU requires that an employer disaggregate the service cost component from the other components of net benefit cost. 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. For other entities, the amendments are effective for annual periods beginning after December 15, 2018, and interim periods within annual periods beginning after December 15, 2019. Early adoption is permitted as of the beginning of an annual period. As disclosed in Note 7, Defined Benefit Plans ASU 2017-05 : The FASB issued ASU 2017-05, Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets. The ASU was issued to clarify the scope of Subtopic 610-20 and to add guidance for partial sales of nonfinancial assets, including partial sales of real estate. Historically, U.S. GAAP contained several different accounting models to evaluate whether the transfer of certain assets qualified for sale treatment. Moving forward, the new standard reduces the number of potential accounting models that might apply and clarifies which model does apply in various circumstances. Specifically, it clarifies the scope of Subtopic 610-20 by defining the term “in substance nonfinancial asset”. If substantially all of the fair value of the assets (recognized and unrecognized) promised to a counterparty in a contract is concentrated in nonfinancial assets, a financial asset in the same arrangement would still be considered part of an in substance nonfinancial asset. Also, nonfinancial assets may include nonfinancial assets contained within a legal entity that is transferred to a counterparty (e.g., through transfer of ownership interest). It clarifies also that derecognition of a business is not within the scope of Subtopic 610-20, but rather, is governed by Topic 810. In addition, the ASU indicates an entity should identify each distinct nonfinancial asset (e.g., real estate and inventory) or in substance nonfinancial asset promised to a counterparty and derecognize each asset when a counterparty obtains control of it. Finally, the ASU adds guidance on accounting for partial sales of nonfinancial assets. It requires an entity to derecognize a distinct nonfinancial asset or distinct in substance nonfinancial asset in a partial sale transaction when two criteria are met: 1) the entity does not have (or ceases to have) a controlling financial interest in the legal entity that holds the asset in accordance with Topic 810, and 2) the entity transfers control of the asset in accordance with Topic 606. The effective date and transition requirements for the ASU are the same as the effective date and transition requirements of Topic 606, and must be applied at the same date that Topic 606 is initially applied. That is, the amendments are effective for public entities for annual reporting periods beginning after December 15, 2017, including interim periods within those periods, and for nonpublic entities for annual reporting periods beginning after December 15, 2018, and interim periods within annual reporting periods beginning after December 15, 2019. Consistent with Topic 606, early adoption is permitted but no earlier than annual reporting periods beginning after December 15, 2016 for all entities. Mid Penn adopted this ASU in the first quarter of 2018. The adoption will not have a material impact on its consolidated financial statements as Mid Penn typically does not engage in partial sale transactions. ASU 2017-04 : The FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The amendments in this ASU are required for public business entities and other entities that have goodwill reported in their financial statements and have not elected the private company alternative for the subsequent measurement of goodwill. To simplify the subsequent measurement of goodwill, the Update eliminates Step 2 from the goodwill impairment test. An entity should now 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 an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. The ASU eliminates the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment, and if it fails that qualitative test, to perform Step 2 of the goodwill impairment test. Therefore, the same impairment assessment applies to all reporting units. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. An entity should apply the amendments in this Update on a prospective basis. A public business entity should adopt the amendments in this Update for its 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. Mid Penn early adopted this ASU for its annual goodwill impairment test as of year-end 2017 by comparing its fair value to its carrying value at that time. The adoption of this ASU did not to have a material impact on Mid Penn’s consolidated financial statements. ASU 2016-15 : The FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments. The ASU clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The amendments are intended to reduce diversity in practice. • Cash payments for debt prepayment or extinguishment costs will be classified in financing activities. • Upon settlement of zero-coupon bonds and bonds with insignificant cash coupons, the portion of the payment attributable to imputed interest will be classified as an operating activity, while the portion of the payment attributable to principal will be classified as a financing activity. • Cash paid by an acquirer that isn’t soon after a business combination for the settlement of a contingent consideration liability will be separated between financing activities and operating activities. Cash payments up to the amount of the contingent consideration liability recognized at the acquisition date will be classified in financing activities; any excess will be classified in operating activities. Cash paid soon after the business combination will be classified in investing activities. • Cash proceeds received from the settlement of insurance claims will be classified on the basis of the related insurance coverage (that is, the nature of the loss). Cash proceeds from lump-sum settlements will be classified based on the nature of each loss included in the settlement. • Cash proceeds received from the settlement of corporate-owned life insurance (“COLI”) and BOLI policies will be classified as cash inflows from investing activities. Cash payments for premiums on COLI and BOLI may be classified as cash outflows for investing, operating, or a combination of both. • A transferor’s beneficial interest obtained in a securitization of financial assets will be disclosed as a noncash activity, and cash received from beneficial interests will be classified in investing activities. • Distributions received from equity method investees will be classified using either a cumulative earnings approach or a look- through approach as an accounting policy election. The ASU contains additional guidance clarifying when an entity should separate cash receipts and cash payments and classify them into more than one class of cash flows (including when reasonable judgment is required to estimate and allocate cash flows) versus when an entity should classify the aggregate amount into one class of cash flows on the basis of predominance. The amendments are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017. For all other entities, the amendments in this Update are effective for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. Early adoption is permitted. 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. An entity that elects early adoption must adopt all of the amendments in the same period. Mid Penn is currently evaluating this ASU, particularly related to cash payments for debt prepayment costs and cash proceeds received from the settlement of BOLI policies as these areas might affect Mid Penn in the future. This ASU, however, is not expected to have a material impact on Mid Penn’s operating results and consolidated financial statements because the guidance only affects the classification within the statement of cash flows. ASU 2016-13 : The FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The ASU 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 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 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 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 Update has tiered effective dates, with early adoption permitted for all entities as of the fiscal year beginning after December 15, 2018. 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. For all other public business entities, the amendments are effective for fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. For all other entities, including not-for-profit entities and employee benefit plans within the scope of Topics 960 through 965 on plan accounting, the amendments are effective for fiscal years beginning after December 15, 2020, and interim periods within fiscal years beginning after December 15, 2021. Mid Penn is currently evaluating the details of this ASU and the impact the guidance will have on Mid Penn’s consolidated financial statements. Mid Penn expects that it is possible that the ASU may result in an increase in the allowance for credit losses resulting from the change to expected losses for the estimated life of the financial asset, including an allowance for debt securities. The amount of the change in the allowance for credit losses, if any, resulting from the new guidance will be impacted by the portfolio composition and asset quality at the adoption date, as well as economic conditions and forecasts at the time of adoption. ASU 2016-09: The FASB issued ASU 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The ASU 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. Early adoption is permitted. As disclosed in Note 9, Common Stock ASU 2016-02: The FASB issued ASU 2016-02, Leases. The new leases standard applies a right-of-use (“ROU”) model that requires a lessee to record, for all leases with a lease term of more than 12 months, an asset representing its right to use the underlying asset and a liability to make lease payments. For leases with a term of 12 months or less, a practical expedient is available whereby a lessee may elect, by class of underlying asset, not to recognize an ROU asset or lease liability. At inception, lessees must classify all leases as either finance or operating based on five criteria. Balance sheet recognition of finance and operating leases is similar, but the pattern of expense recognition in the income statement, as well as the effect on the statement of cash flows, differs depending on the lease classification. The new leases standard requires a lessor to classify leases as either sales-type, direct financing or operating, similar to existing U.S. GAAP. Classification depends on the same five criteria used by lessees plus certain additional factors. The subsequent accounting treatment for all three lease types is substantially equivalent to existing U.S. GAAP for sales-type leases, direct financing leases, and operating leases. However, the new standard updates certain aspects of the lessor accounting model to align it with the new lessee accounting model, as well as with the new revenue standard under Topic 606. Lessees and lessors are required to provide certain qualitative and quantitative disclosures to enable users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The new leases standard addresses other considerations including identification of a lease, separating lease and non-lease components of a contract, sale and leaseback transactions, modifications, combining contracts, reassessment of the lease term, and re-measurement of lease payments. It also contains comprehensive implementation guidance with practical examples. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. Specific transition requirements apply. Mid Penn occupies certain offices under non-cancelable operating lease agreements, which currently are not reflected in its consolidated statement of condition. Mid Penn expects to recognize lease liabilities and ROU assets associated with these lease agreements as required by the ASU; however, the extent of the prospective impact on Mid Penn’s consolidated financial statements and the materiality will be dependent upon the extent and type of lease arrangements involving Mid Penn at the time of the adoption of this standard. ASU 2016-01: The FASB issued ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities . This ASU requires equity investments to be measured at fair value with changes in fair value recognized in net income, excluding equity investments that are consolidated or accounted for under the equity method of accounting. The ASU allows equity investments without readily determinable fair values to be measured at cost minus impairment, with a qualitative assessment required to identify impairment. The ASU also requires public companies to use exit prices to measure the fair value of financial instruments, eliminates the disclosure requirements related to measurement assumptions for the fair value of instruments measured at amortized cost, and requires separate presentation of financial assets and liabilities based on form and measurement category. In addition, for liabilities measured at fair value under the fair value option, the changes in fair value due to changes in instrument-specific credit risk should be recognized in OCI. This ASU is effective for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. As of December 31, 2017, Mid Penn held $856,000 of equity investments (excluding restricted investments in bank stocks). Mid Penn does not expect to make significant increases in the volume of its equity investments; therefore, the adoption of this ASU is not expected to be material to Mid Penn’s consolidated financial statements. ASU 2014-09 : 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. In August 2015, the FASB issued ASU 2015-14, Revenue from contracts with Customers (Topic 606): Deferral of the Effective Date 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) In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing , In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients In November 2017, the FASB issued ASU 2017-14, Income Statement – Reporting Comprehensive Income (Topic 220), Revenue Recognition (Topic 605), and Revenue from Contracts with Customers (Topic 606) – Amendments to SEC Paragraphs Pursuant to Staff Accounting Bulletin No. 116 and SEC Release No. 33-10403. The ASU adds guidance to the existing Staff Bulletin No. 116 stating that SAB Topic 13 (Revenue Recognition) and SAB Topic 8 (Retail Companies) are no longer applicable once a registrant adopts Topic 606. ASU 2014-09, including transition requirements for all amendments, is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. Early adoption is permitted as of the original effective date for interim and annual reporting periods in fiscal years beginning after December 15, 2016. Mid Penn completed its internal assessment procedure related to this Standard during the fourth quarter of 2017 and fully adopted the standard in the first quarter of 2018. Through our assessment, we identified certain non-interest income financial statement line items that met the criteria of this Standard and worked through the five step assessment process for each line item within the scope of the Standard. Mid Penn has concluded that the adoption of the Standard using the modified retrospective approach will have no financial statement impact as the current financial statement line items within the scope of this Standard are in compliance with the new guidance, however, we expect the adoption will require additional qualitative and quantitative disclosure requirements related to revenue recognition within our quarterly and annual reports. We will continue to evaluate any prospective impact as additional guidance is issued and will update our internal assessment at least annually, or more frequently if necessary. ASU 2018-02 : The FASB issued ASU No. 2018-02, Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . This ASU provides guidance related to the stranded income tax effects in accumulated other comprehensive income caused by the Tax Cuts and Jobs Act by providing financial statement preparers with the option to reclassify stranded tax effects in accumulated other comprehensive income to retained earnings in every period wherein the impact of the new corporate income tax rate in the new tax law (or portion thereof) is recognized. As a result of the new guidance, financial statement preparers must provide a description of the accounting policy for reclassifying income tax effects from accumulated other comprehensive income. Preparers are also required to disclose whether they will reclassify the stranded income tax effects from tax reform, and provide information on the other reclassified tax effects. Mid Penn has early adopted ASU 2018-02 effective December 31, 2017. Mid Penn had $341,000 of stranded income tax effects in accumulated other comprehensive loss within the capital section on the balance sheet as a result of the Tax Cuts and Jobs Act. The majority of this amount was derived from the accumulated other comprehensive loss on available-for-sale investment securities, while the remaining balance is attributable to Mid Penn’s post-retirement benefit plans. The adoption of ASU 2018-02 resulted in the transfer of the $341,000 of stranded income tax effects out of accumulated other comprehensive income and into retained earnings with no impact to total shareholders’ equity or net income.

Summary of Quarterly Consolidat

Summary of Quarterly Consolidated Financial Data	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Data [Abstract]
Summary of Quarterly Consolidated Financial Data	(25) Summary of Quarterly Consolidated Financial Data (Unaudited) The following table presents summarized quarterly financial data for 2017 and 2016. (Dollars in thousands, except per share data) 2017 Quarter Ended March 31 June 30 September 30 December 31 Interest Income $ 10,559 $ 10,879 $ 11,150 $ 11,304 Interest Expense 1,384 1,469 1,634 1,817 Net Interest Income 9,175 9,410 9,516 9,487 Provision for Loan and Lease Losses 125 100 — 100 Net Interest Income After Provision for Loan Losses 9,050 9,310 9,516 9,387 Noninterest Income 1,436 1,362 1,564 1,331 Noninterest Expense 7,802 7,558 7,960 8,047 Income Before Provision for Income Taxes 2,684 3,114 3,120 2,671 Provision for Income Taxes 690 769 871 2,170 Net Income Available to Common Shareholders $ 1,994 $ 2,345 $ 2,249 $ 501 Per Share Data: Basic Earnings Per Common Share $ 0.47 $ 0.55 $ 0.53 $ 0.12 Cash Dividends Declared 0.13 0.13 0.13 0.38 (Dollars in thousands, except per share data) 2016 Quarter Ended March 31 June 30 September 30 December 31 Interest Income $ 9,697 $ 9,859 $ 10,125 $ 10,531 Interest Expense 1,282 1,316 1,367 1,402 Net Interest Income 8,415 8,543 8,758 9,129 Provision for Loan and Lease Losses 340 395 585 550 Net Interest Income After Provision for Loan Losses 8,075 8,148 8,173 8,579 Noninterest Income 1,232 1,398 1,419 1,875 Noninterest Expense 6,982 6,931 7,165 7,740 Income Before Provision for Income Taxes 2,325 2,615 2,427 2,714 Provision for Income Taxes 520 593 526 638 Net Income Available to Common Shareholders $ 1,805 $ 2,022 $ 1,901 $ 2,076 Per Share Data: Basic Earnings Per Common Share $ 0.43 $ 0.48 $ 0.45 $ 0.49 Cash Dividends Declared 0.22 0.12 0.12 0.22

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	(2 6 ) Subsequent Events The Scottdale Bank & Trust Company On January 8, 2018, Mid Penn completed its acquisition of The Scottdale Bank & Trust Company, a Pennsylvania bank and trust company (“Scottdale”), through the merger of Scottdale with and into Mid Penn Bank pursuant to that certain previously announced Agreement and Plan of Merger, dated as of March 29, 2017, among Mid Penn, Mid Penn Bank and Scottdale. Pursuant to the Merger Agreement, each share of Scottdale common stock issued and outstanding immediately prior to January 8, 2018 converted into the right to receive (i) $1,166 in cash without interest or (ii) 38.88 shares of Mid Penn common stock. As a result, Mid Penn issued approximately 1.9 million shares of Mid Penn common stock and cash of approximately $2.8 million. The transaction was valued at approximately $66,972,000. At December 31, 2017, and eight days prior to the acquisition transaction, Scottdale reported total assets of $260,735,000, total loans of $69,328,000, and total deposits of $210,658,000 on a Call Report filed with federal banking regulators. Given that the initial purchase accounting for the acquisition in accordance with generally accepted accounting principles for this business combination is not yet completed, Mid Penn is not yet able to disclose the preliminary fair value of the Scottdale assets acquired and liabilities assumed. First Priority Financial Corp. On January 16, 2018, Mid Penn entered into an Agreement and Plan of Merger (the “Merger Agreement”) with First Priority Financial Corp. (“First Priority”) pursuant to which First Priority will merge with and into Mid Penn (the “Merger”), with Mid Penn being the surviving corporation in the Merger. The acquisition will expand Mid Penn’s footprint into southeastern Pennsylvania, including Chester, Berks, Montgomery, and Bucks counties. On a pro forma basis, the combined company will have over $2 billion in total assets. Under the terms of the Merger Agreement, shareholders of First Priority will receive 0.3481 shares of Mid Penn common stock for each share of First Priority common stock they own. Subject to customary closing conditions including regulatory and shareholder approvals, it is expected that the Merger will be completed in the third quarter of 2018.

Summary of Significant Accoun36

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Use of Estimates	(a) Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan and lease losses, the assessment of other-than-temporary impairment of investment securities, the valuation of the goodwill for impairment, and the valuation of assets acquired and liabilities assumed in business combinations.
Cash and Cash Equivalents	(b) Cash and Cash Equivalents For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash on hand, balances due from banks, and federal funds sold, all of which mature within ninety days.
Investment Securities	(c) Interest-bearing Time Deposits with Other Financial Institutions Interest-bearing time deposits with other financial institutions consist of certificates of deposits in other financial institutions with maturities within one year. (d) Investment Securities Available-for-sale securities include debt and equity securities which are reported at fair value, with unrealized holding gains and losses excluded from earnings being reported, net of deferred income taxes, as a component of accumulated other comprehensive income (loss) within shareholders’ equity. During 2017, Mid Penn added a held-to-maturity pool to its overall investment portfolio of debt securities, which are reported at amortized cost. Unrealized holding gains and losses on held-to-maturity securities are excluded from earnings, and are not a component of accumulated other comprehensive income (loss) within shareholders’ equity. As of December 31, 2017, Mid Penn had $101,356,000 of held-to-maturity securities recorded at amortized cost. Mid Penn had no held-to-maturity securities in 2016 and 2015. Premiums and discounts on debt securities are amortized as an adjustment to interest income using the interest method. Realized gains and losses on sales of investment securities are computed on the basis of specific identification of the cost of each security. Net gains on sales of investment securities were $42,000 in 2017, $1,046,000 in 2016, and $325,000 in 2015.
Loans Held for Sale	(e) Loans Held for Sale Mortgage loans originated and intended for sale in the secondary market are included in loans held for sale and are carried at fair value, as determined by outstanding commitments from investors. Gains and losses on sales of mortgage loans are included in the Consolidated Statements of Income in mortgage banking income. Mortgage banking income was $872,000 in 2017, $922,000 in 2016, and $456,000 in 2015.
Loans and Allowance for Loan and Lease Losses	(f) Loans and Allowance for Loan and Lease Losses Loans receivable that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are stated at their outstanding unpaid principal balances, net of an allowance for loan losses and any deferred fees or costs. Interest income is accrued on the unpaid principal balance. Residential loans held for sale are carried at fair value and are included in loans held for sale on the balance sheet. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the yield (interest income) of the related loans. These amounts are generally being amortized over the contractual life of the loan. Premiums and discounts on purchased loans are amortized as adjustments to interest income using the effective yield method. The loan portfolio is segmented into commercial and consumer loans. Commercial loans consist of the following classes: commercial and industrial, commercial real estate, commercial real estate-construction and lease financing. Consumer loans consist of the following classes: residential mortgage loans, home equity loans and other consumer loans. For all classes of loans, the accrual of interest is discontinued when the contractual payment of principal or interest has become 90 days or more past due or management has serious doubts about further collectability of principal or interest, even though the loan is currently performing. A loan may remain on accrual status if it is in the process of collection and is either guaranteed or well secured. When a loan is placed on nonaccrual status, unpaid interest is credited to income. Interest received on nonaccrual loans, including impaired loans, generally is either applied against principal or reported as interest income, according to management’s judgment as to the collectability of principal. Generally, loans are restored to accrual status when the obligation is brought current, has performed in accordance with the contractual terms for a reasonable period of time (generally six months) and the ultimate collectability of the total contractual principal and interest is no longer in doubt. The past due status of all classes of loans receivable is determined based on contractual due dates for loan payments. Commercial and industrial Mid Penn originates commercial and industrial loans. Most of the Bank’s commercial and industrial loans have been extended to finance local and regional businesses and include short-term loans to finance machinery and equipment purchases, inventory, and accounts receivable. Commercial loans also involve the extension of revolving credit for a combination of equipment acquisitions and working capital in expanding companies. The maximum term for loans extended on machinery and equipment is based on the projected useful life of such machinery and equipment. Generally, the maximum term on non-mortgage lines of credit is one year. The loan-to-value ratio on such loans and lines of credit generally may not exceed 80% of the value of the collateral securing the loan. The Bank’s commercial business lending policy includes credit file documentation and analysis of the borrower’s character, capacity to repay the loan, the adequacy of the borrower’s capital and collateral, as well as an evaluation of conditions affecting the borrower. Analysis of the borrower’s past, present, and future cash flows is also an important aspect of the Bank’s current credit analysis. Nonetheless, such loans are believed to carry higher credit risk than other extensions of credit. Commercial and industrial loans typically are made on the basis of the borrower’s ability to make repayment from the cash flow of the borrower’s business. As a result, the availability of funds for the repayment of commercial business loans may be substantially dependent on the success of the business itself, which, in turn, is likely to be dependent upon the general economic environment. Mid Penn’s commercial and industrial loans are usually, but not always, secured by business assets and personal guarantees. However, the collateral securing the loans may depreciate over time, may be difficult to appraise, and may fluctuate in value based on the success of the business. Commercial real estate and commercial real estate - construction Commercial real estate and commercial real estate construction loans generally present a higher level of risk than loans secured by one to four family residences. This greater risk is due to several factors, including the concentration of principal in a limited number of loans and borrowers, the effect of general economic conditions on income producing properties, and the increased difficulty of evaluating and monitoring these types of loans. In addition, the repayment of loans secured by commercial real estate is typically dependent upon the successful operation of the related real estate project. If the cash flow from the project is reduced, the borrower’s ability to repay the loan may be impaired. Residential mortgage Mid Penn offers a wide array of residential mortgage loans for both permanent structures and those under construction. The Bank’s residential mortgage originations are secured primarily by properties located in its primary market and surrounding areas. Residential mortgage loans have terms up to a maximum of 30 years and with loan to value ratios up to 100% of the lesser of the appraised value of the security property or the contract price. Private mortgage insurance is generally required in an amount sufficient to reduce the Bank’s exposure to at or below the 85% loan to value level. Residential mortgage loans generally do not include prepayment penalties. In underwriting residential mortgage loans, the Bank evaluates both the borrower’s ability to make monthly payments and the value of the property securing the loan. Most properties securing real estate loans made by Mid Penn are appraised by independent fee appraisers. The Bank generally requires borrowers to obtain title insurance and fire and property insurance (including flood insurance, if necessary) in an amount not less than the amount of the loan. Real estate loans originated by the Bank generally contain a “due on sale” clause allowing the Bank to declare the unpaid principal balance due and payable upon the sale of the security property. The Bank underwrites residential mortgage loans to the standards established by the secondary mortgage market, i.e., Fannie Mae, Ginnie Mae, Freddie Mac, or Pennsylvania Housing Finance Agency standards, with the intention of selling the majority of residential mortgages originated into the secondary market. In the event that the facts and circumstances surrounding a residential mortgage application do not meet all underwriting conditions of the secondary mortgage market, the Bank will evaluate the failed conditions and evaluate the potential risk of holding the residential mortgage in the Bank’s portfolio rather than rejecting the loan request. In the event that the loan is held in the Bank’s portfolio, the interest rate on the residential mortgage typically would be increased to compensate for the added portfolio risk. Consumer, including home equity Mid Penn offers a variety of secured consumer loans, including home equity, automobile, and deposit secured loans. In addition, the Bank offers other secured and unsecured consumer loans. Most consumer loans are originated in Mid Penn’s primary market and surrounding areas. The largest component of Mid Penn’s consumer loan portfolio consists of fixed rate home equity loans and variable rate home equity lines of credit. Substantially all home equity loans and lines of credit are secured by second mortgages on principal residences. The Bank will lend amounts, which, together with all prior liens, typically may be up to 85% of the appraised value of the property securing the loan. Home equity term loans may have maximum terms up to 20 years while home equity lines of credit generally have maximum terms of five years. Consumer loan terms vary according to the type and value of collateral, length of contract and creditworthiness of the borrower. The underwriting standards employed by the Bank for consumer loans include an application, a determination of the applicant’s payment history on other debts, and an assessment of ability to meet existing obligations and payments on the proposed loan. Although creditworthiness of the applicant is a primary consideration, the underwriting process also includes a comparison of the value of the collateral, if any, in relation to the proposed loan amount. Consumer loans may entail greater credit risk than do residential mortgage loans, 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. 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 that can be recovered on such loans. 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 weakens and property values deteriorate. Allowance for Loan and Lease Losses The allowance for credit losses consists of the allowance for loan and lease losses and the reserve for unfunded lending commitments. The allowance for loan and lease losses represents management’s estimate of losses inherent in the loan portfolio as of the balance sheet date and is recorded as a reduction to loans. Mid Penn also estimates a reserve for unfunded lending commitments, which represents management’s estimate of losses inherent in its unfunded loan commitments and is recorded in other liabilities on the consolidated balance sheet. The reserve for unfunded loan commitments was $105,000 at December 31, 2017 and $120,000 at December 31, 2016. The allowance for loan and lease losses is increased by the provision for loan and lease losses, and decreased by charge-offs, net of recoveries. Loans deemed to be uncollectible are charged against the allowance for loan and lease losses, and subsequent recoveries, if any, are credited to the allowance. All, or part, of the principal balance of loans are charged off to the allowance as soon as it is determined that the repayment of all, or part, of the principal balance is highly unlikely. Non-residential consumer loans are generally charged off no later than 120 days past due on a contractual basis, earlier in the event of bankruptcy, or if there is an amount deemed uncollectible. Because all identified losses are immediately charged off, no portion of the allowance for loan and lease losses is restricted to any individual loan or groups of loans, and the entire allowance is available to absorb any and all loan losses. The allowance for credit losses is maintained at a level considered adequate to provide for losses that can be reasonably anticipated. Management performs a monthly evaluation of the adequacy of the allowance. The allowance is based on Mid Penn’s past loan loss experience, known and inherent risks in the portfolio, adverse situations that may affect the borrower’s ability to repay, the estimated value of any underlying collateral, composition of the loan portfolio, current economic conditions, and other relevant factors. This evaluation is inherently subjective as it requires material estimates that may be 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 impaired. For loans that are classified as impaired, an allowance is established when the discounted cash flows (“DCF”), 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 each of these categories of loans, adjusted for qualitative factors. These qualitative risk factors include changes in economic conditions, fluctuations in loan quality measures, changes in collateral values, changes in the experience of the lending staff and loan review systems, changes in lending policies and procedures, including underwriting standards, changes in the mix and volume of loans originated, the effect of other external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in the existing loan portfolio, and shifting industry or portfolio 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. Mid Penn generally considers a commercial loan (consisting of commercial and industrial, commercial real estate, commercial real estate-construction, and lease financing loan classes) to be impaired when it becomes 90 days or more past due and not in the process of collection or sooner when it is probable that Mid Penn will be unable to collect all contractual principal and interest due. This methodology assumes the borrower cannot or will not continue to make additional payments. At that time the loan would generally be considered collateral dependent as the DCF method would generally indicate no operating income available for evaluating the collateral position; therefore, most impaired loans are deemed to be collateral dependent. In addition, Mid Penn’s rating system assumes any loans classified as nonaccrual, included in the substandard rating, to be impaired, and most of these loans are considered collateral dependent; therefore, most of Mid Penn’s impaired loans, whether reporting a specific allocation or not, are considered collateral dependent. Mid Penn evaluates loans for charge-off on a monthly basis. Policies that govern the recommendation for charge-off are unique to the type of loan being considered. Commercial loans rated as substandard nonaccrual or lower will first have a collateral evaluation completed in accordance with the guidance on impaired loans. Once the collateral evaluation has been completed, a specific allocation of allowance is made based upon the results of the evaluation. The remaining balance remains a nonperforming loan with the original terms and interest rate intact (not restructured). In the event the loan is unsecured, the loan would have been charged-off at the recognition of impairment. Commercial real estate loans rated as impaired will also have an initial collateral evaluation completed in accordance with the guidance on impaired loans. An updated real estate valuation is ordered and the collateral evaluation is modified to reflect any variations in value. A specific allocation of allowance is made for any anticipated collateral shortfall. The remaining balance remains a nonperforming loan with the original terms and interest rate intact (not restructured). The process of charge-off for residential mortgage loans begins upon a loan becoming delinquent for 90 days and not in the process of collection. The existing appraisal is reviewed and a lien search is obtained to determine lien position and any instances of intervening liens. A new appraisal of the property will be ordered if deemed necessary by management and a collateral evaluation is completed. The loan will then be charged down to the value indicated in the evaluation. Consumer loans (including home equity loans and other consumer loans) are recommended for charge-off after reaching delinquency of 90 days and the loan is not in the process of collection. The collateral shortfall of the consumer loan is recommended for charge-off at this point. As noted above, Mid Penn assesses a specific allocation for commercial loans and commercial real estate loans. The remaining balance remains a nonperforming loan with the original terms and interest rate intact (not restructured). In addition, Mid Penn takes a preemptive step when any commercial loan becomes classified under its internal classification system. A preliminary collateral evaluation, in accordance with the guidance on impaired loans, is prepared using the existing collateral information in the loan file. This process allows Mid Penn to review both the credit and documentation files to determine the status of the information needed to make a collateral evaluation. This collateral evaluation is preliminary but allows Mid Penn to determine if any potential collateral shortfalls exist. It is Mid Penn’s policy to obtain updated third party valuations on all impaired loans collateralized by real estate as soon as practically possible of the credit being classified as substandard nonaccrual. Prior to receipt of the updated real estate valuation Mid Penn will use any existing real estate valuation to determine any potential allowance issues; however, no allowance recommendation will be made until such time Mid Penn is in receipt of the updated valuation. The Asset Recovery department employs an electronic tracking system to monitor the receipt of and need for updated appraisals. To date, there have been no material time lapses noted with the above processes. In some instances Mid Penn is not holding real estate as collateral and is relying on business assets (personal property) for repayment. In these circumstances a collateral inspection is performed by Mid Penn personnel to determine an estimated value. The value is based on net book value, as provided by the financial statements, and discounted accordingly based on determinations made by management. Occasionally, Mid Penn will employ an outside service to provide a fair estimate of value based on auction sales or private sales. Management reviews the estimates of these third parties and discounts them accordingly based on management’s judgment, if deemed necessary. For impaired loans with no valuation allowance required, Mid Penn’s practice of obtaining independent third party market valuations on the subject property as soon as practically possible of the credit being placed on nonaccrual status sometimes indicates that the loan to value ratio is sufficient to obviate the need for a specific allocation in spite of significant deterioration in real estate values in Mid Penn’s primary market area. These circumstances are determined on a case by case analysis of the impaired loans. Mid Penn actively monitors the values of collateral on impaired loans. This monitoring may require the modification of collateral values over time or changing circumstances by some factor, either positive or negative, from the original values. All collateral values will be assessed by management at least every 12 months for possible revaluation by an independent third party. An unallocated component is maintained to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance for loan and lease losses covers several considerations that are not specifically measureable through either the specific and general components. For example, we believe that we could face credit risks and uncertainties, not reflected in recent historical losses or qualitative factor assessments, associated with unpredictable changes in economic growth or business conditions in our markets or for certain industries in which we have commercial loan borrowers, or unanticipated stresses to the values of real estate held as collateral. Any or all of these additional issues can adversely affect our borrowers’ ability to timely repay their loans. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, Mid Penn does not separately identify individual residential mortgage loans, home equity loans and other consumer loans for impairment disclosures, unless such loans are the subject of a troubled debt restructuring agreement. Loans whose terms are modified are classified as troubled debt restructurings if the borrowers have been granted concessions 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 or an extension of a loan’s stated maturity date. Nonaccrual troubled debt restructurings are restored to accrual status if principal and interest payments, under the modified terms, are current for six consecutive months after modification. Loans classified as troubled debt restructurings are designated as impaired. The allowance calculation methodology includes further segregation of loan classes into risk rating categories. The borrower’s overall financial condition, repayment sources, guarantors, and value of collateral, if appropriate, are 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 criticized as 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. Any loans not classified as noted above are rated pass. In addition, Federal and State regulatory agencies, as an integral part of their examination process, periodically review the Bank’s allowance for loan and lease losses and may require the Bank 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, management believes the current level of the allowance for loan losses is adequate. Acquired Loans Loans that Mid Penn acquires in connection with business combinations are recorded at fair value with no carryover of the existing related allowance for loan losses. Fair value of the loans involves estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest. The excess of cash flows expected at acquisition over the estimated fair value is referred to as the accretable discount and is recognized into interest income over the remaining life of the loan. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable discount. These loans are accounted for under the Accounting Standard Codification (“ASC”) 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality Loans acquired through business combinations that do meet the specific criteria of ASC 310-30 are individually evaluated each period to analyze expected cash flows. To the extent that the expected cash flows of a loan have decreased due to credit deterioration, Mid Penn establishes an allowance. Loans acquired through business combinations that do not meet the specific criteria of ASC 310-30 are accounted for under ASC 310-20. These loans are initially recorded at fair value, and include credit and interest rate marks associated with acquisition accounting adjustments. Purchase premiums or discounts are subsequently amortized as an adjustment to yield over the estimated contractual lives of the loans. There is no allowance for loan losses established at the acquisition date for acquired performing loans. An allowance for loan losses is recorded for any credit deterioration in these loans subsequent to acquisition. Acquired loans that met the criteria for impaired or nonaccrual of interest prior to the acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent if Mid Penn expects to fully collect the new carrying value (i.e. fair value) of the loans. As such, Mid Penn may no longer consider the loan to be nonaccrual or nonperforming and may accrue interest on these loans, including the impact of any accretable discount. In addition, charge-offs on such loans would be first applied to the nonaccretable difference portion of the fair value adjustment.
Bank Premises and Equipment	(g) Bank Premises and Equipment Land is carried at cost. Buildings, furniture, fixtures, equipment, land improvements, and leasehold improvements are stated at cost less accumulated depreciation. Depreciation is computed by the straight-line method over the estimated useful lives of the assets. Building assets are depreciated using an estimated useful life of five to fifty years. Furniture, fixtures, and equipment are depreciated using an estimated useful life of three to ten years. Land improvements are depreciated over an estimated useful life of ten to twenty years. Leasehold improvements are depreciated using an estimated useful life that is the lesser of the remaining life of the lease or ten to thirty years. Maintenance and normal repairs are charged to expense when incurred, while major additions and improvements are capitalized. Gains and losses on disposals are reflected in current operations. Bank premises and equipment designated as held for sale are carried at the lower of cost or market value.
Restricted Investment in Federal Home Loan Bank Stock	(h) Restricted Investments in Bank Stocks Restricted investments in bank stocks represent required investments in the common stock of correspondent banks. As a member of the FHLB and Atlantic Community Bankers Bank (“ACBB”), the Bank is required to own restricted stock investments in these correspondent banks, which is carried at cost. The total amount of these restricted stock investments was $4,384,000 December 31, 2017 and $2,443,000 at December 31, 2016. This increase was attributed to Mid Penn’s shift from a short-term selling position to a short-term borrowing position in 2017. Total dividends received in 2017 and 2016 totaled $114,000 and $135,000, respectively.
Foreclosed Assets Held for Sale	(i) Foreclosed Assets Held for Sale Foreclosed assets held for sale consist primarily of real estate acquired through, or in lieu of, foreclosure in settlement of debt, and are recorded at fair value less cost to sell at the date of transfer, establishing a new cost basis. Any valuation adjustments required at the date of transfer are charged to the allowance for loan losses. Subsequent to acquisition, foreclosed assets are carried at fair value less costs of disposal, based upon periodic evaluations that consider changes in market conditions and development and disposal costs. Operating results from assets acquired in satisfaction of debt, including rental income less operating costs and gains or losses on the sale of, or the periodic evaluation of foreclosed assets, are recorded in noninterest expense. As of December 31, 2017, Mid Penn had $42,000 of residential real estate held in other real estate owned. There was $308,000 in loans for which formal foreclosure proceedings were in process at December 31, 2017. As of December 31, 2016, Mid Penn had $57,000 of residential real estate held in other real estate owned. There was $426,000 in loans for which formal foreclosure proceedings were in process at December 31, 2016.
Mortgage Servicing Rights	(j) Mortgage Servicing Rights Mortgage servicing rights are recognized as assets upon the sale of a mortgage loan. A portion of the cost of the loan is allocated to the servicing right based upon relative fair value. The fair value of servicing rights is based on the present value of estimated future cash flows of mortgages sold, stratified by rate and maturity date. Assumptions that are incorporated in the valuation of servicing rights include assumptions about prepayment speeds on mortgages and the cost to service loans. Servicing rights are reported in core deposit and other intangibles in the Consolidated Balance Sheets and are amortized over the estimated period of future servicing income to be received on the underlying mortgage loans. The carrying amount of mortgage servicing rights was $126,000 and $144,000 at December 31, 2017 and 2016, respectively. Amortization expense is reflected in the Consolidated Statements of Income in other income and was $18,000, $30,000, and $24,000 for the years 2017, 2016, and 2015, respectively. Servicing rights are evaluated for impairment based upon estimated fair value as compared to unamortized carrying value.
Investment in Limited Partnership	(k) Investment in Limited Partnership Mid Penn is a limited partner in a partnership that provides low-income housing in Enola, Pennsylvania. The carrying value of Mid Penn’s investment in the limited partnership was $277,000 at December 31, 2017 and $321,000 at December 31, 2016, net of amortization, using the straight-line method and is reported in other assets on the Consolidated Balance Sheets. Mid Penn’s maximum exposure to loss is limited to the carrying value of its investment. The partnership received $46,000 in low-income housing tax credits during 2017, 2016 and 2015.
Income Taxes	(l) Income Taxes Mid Penn accounts for income taxes in accordance with income tax accounting guidance ASC Topic 740, Income Taxes Current income tax accounting guidance results in two components of income tax expense: current and deferred. Current income tax expense reflects taxes to be paid or refunded for the current period by applying the provisions of the enacted tax law to the taxable income or excess of deductions over revenues. Mid Penn determines deferred income taxes using the liability (or balance sheet) method. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax basis of assets and liabilities, and enacted changes in tax rates and laws are recognized in the period in which they occur. Deferred income tax expense results from changes in deferred tax assets and liabilities between periods. Deferred tax assets are reduced by a valuation allowance if, based on the weight of the evidence available, it is more likely than not that some portion or all of a deferred tax asset will not be realized. Mid Penn accounts for uncertain tax positions if it is more likely than not, based on the technical merits, that the tax position will be realized or sustained upon examination. The term more-likely-than-not means a likelihood of more than 50%; the terms examined and upon examination also include resolution of the related appeals or litigation processes, if any. A tax position that meets the more-likely-than-not recognition threshold is initially and subsequently measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The determination of whether or not a tax position has met the more-likely-than-not recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to management's judgment. Mid Penn recognizes interest and penalties on income taxes, if any, as a component of income tax expense. On December 22, 2017, President Donald J. Trump signed into law the Tax Cuts and Jobs Act (the “TCJA”), a tax reform law that included a significant provision reducing the corporate tax rate applicable to Mid Penn, for tax years beginning after 2017, to a flat 21 percent rate. Though the reduced rate will provide tax savings to Mid Penn in future periods after 2017, the reduction resulted in the $1,169,000 write-down of Mid Penn’s deferred tax asset in December 2017, because the deferred tax asset was previously valued based upon the projection of Mid Penn realizing a 34 percent future corporate tax rate benefit. This write-down was included in Mid Penn’s income tax provision for the year ended December 31, 2017, as further discussed in Note 17 (Federal Income Taxes) to the consolidated financial statements.
Core Deposit Intangible	(m) Core Deposit Intangible Core deposit intangible is a measure of the value of consumer demand and savings deposits acquired in business combinations accounted for as purchases. The core deposit intangible is being amortized over a ten-year period using a sum of the year’s digits basis. The core deposit intangible is subject to impairment testing whenever events or changes in circumstances indicate such testing.
Goodwill	(n) Goodwill Goodwill is the excess of the purchase price over the fair value of assets acquired in connection with past business acquisitions, including the 2015 Phoenix acquisition. The recorded value of goodwill as of December 31, 2017, does not include any amount related to the acquisition of The Scottdale Bank and Trust Company as the legal close of that acquisition did not occur until January 8, 2018. Goodwill is evaluated annually for impairment; however, if certain events occur, which indicate goodwill might be impaired between annual tests, goodwill must be tested when such events occur. In making this goodwill potential impairment assessment, Mid Penn considers a number of factors including operating results, business plans, economic projections, anticipated future cash flows, current market data, stock price, etc. There are inherent uncertainties related to these factors and Mid Penn’s judgment in applying them to the analysis of goodwill impairment. Changes in economic and operating conditions could result in goodwill impairment in future periods. Mid Penn did not identify any impairment on its outstanding goodwill from its most recent testing, which was performed as of December 31, 2017 using a qualitative analysis. In addition, Mid Penn did not identify any impairment in 2016 using a qualitative analysis or in 2015 using a qualitative and quantitative analyses in accordance with ASC 350.
Bank Owned Life Insurance	(o) Bank Owned Life Insurance Mid Penn is the owner and beneficiary of bank-owned life insurance (“BOLI”) policies on current and former directors, as well as select Miners Bank employees, which were acquired through the Phoenix acquisition. The earnings from the BOLI policies are an asset that can be liquidated, if necessary, with associated tax costs. However, Mid Penn intends to hold these policies and, accordingly, Mid Penn has not provided deferred income taxes on the earnings from the increase in cash surrender value. Mid Penn is also party to certain Split-Dollar Life Insurance Arrangements, and in accordance with GAAP, has accrued a liability related to the postretirement benefits covered by an endorsement split-dollar life insurance arrangement, and a liability for the future death benefit.
Marketing and Advertising Costs	(p) Marketing and Advertising Costs Marketing and advertising costs are expensed as incurred.
Postretirement and Other Benefit Plans	(q) Postretirement Benefit Plans Mid Penn follows the guidance in ASC Topic 715, Compensation-Retirement Benefits (r) Other Benefit Plan A funded contributory defined-contribution plan is maintained for substantially all employees. The cost of the Mid Penn defined contribution plan is charged to current operating expenses and is funded annually.
Trust Assets and Income	(s) Trust Assets and Income Assets held by the Bank in a fiduciary or agency capacity for customers of the Trust Department are not included in the consolidated financial statements since such items are not assets of the Bank. Trust income is recognized on the cash basis, which is not materially different than if it were reported on the accrual basis.
Comprehensive Income	(t) Comprehensive Income Comprehensive income consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes changes in unrealized gains and losses on securities available for sale arising during the period and reclassification adjustments for realized gains and losses on securities available for sale included in net income. Mid Penn has an unfunded noncontributory defined benefit Plan for directors and other postretirement benefit Plans covering full-time employees. These Plans utilize assumptions and methods to calculate the fair value of Plan assets and recognizing the overfunded and underfunded status of the Plans on its consolidated balance sheet. Gains and losses, prior service costs and credits are recognized in other comprehensive income (loss), net of tax, until they are amortized, or immediately upon curtailment.
Restricted stock	(u) Restricted Stock Mid Penn provides members of senior management who have a responsibility for its growth with additional incentives by allowing them to acquire an ownership interest in Mid Penn through its Restricted Stock Plan. The restricted stock is non-voting and non-participating until the granted shares vest. Once the shares vest, the recipient would have full voting rights and be entitled to any common stock dividends.
Earning Per Share	(v) Earnings Per Share Earnings per share are computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding during each of the years presented. The following data show the amounts used in computing basic earnings per share. (Dollars in thousands, except per share data) 2017 2016 2015 Net Income $ 7,089 $ 7,804 $ 6,528 Less: Dividends on Series B preferred stock — — 373 Redemption premium on Series B preferred stock — — 100 Dividends on Series C preferred stock — — 17 Net income available to common shareholders $ 7,089 $ 7,804 $ 6,038 Weighted average common shares outstanding 4,236,616 4,229,284 4,106,548 Basic earnings per common share $ 1.67 $ 1.85 $ 1.47 Mid Penn had no dilutive instruments outstanding during the periods ended December 31, 2017, 2016, and 2015.

Summary of Significant Accoun37

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Basic Earnings (Loss) Per Share	The following data show the amounts used in computing basic earnings per share. (Dollars in thousands, except per share data) 2017 2016 2015 Net Income $ 7,089 $ 7,804 $ 6,528 Less: Dividends on Series B preferred stock — — 373 Redemption premium on Series B preferred stock — — 100 Dividends on Series C preferred stock — — 17 Net income available to common shareholders $ 7,089 $ 7,804 $ 6,038 Weighted average common shares outstanding 4,236,616 4,229,284 4,106,548 Basic earnings per common share $ 1.67 $ 1.85 $ 1.47

Mergers and Acquisitions (Table

Mergers and Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Allocation of the Purchase Price	The allocation of the purchase price of the Phoenix acquisition is as follows: (Dollars in thousands) Assets acquired: Cash and cash equivalents $ 11,044 Investment securities 11,331 Loans 110,363 Goodwill 2,902 Core deposit and other intangibles 578 Other assets 7,489 Total assets acquired 143,707 Liabilities assumed: Deposits 123,238 FHLB borrowings 3,570 Other liabilities 908 Total liabilities assumed 127,716 Equity acquired: Preferred stock 1,750 Total equity acquired and liabilities assumed 129,466 Consideration paid $ 14,241 Cash paid $ 2,949 Fair value of common stock issued, including replacement equity awards 11,292
Summary of the Estimated Fair Value of the Assets Acquired and Liabilities and Equity Assumed	The following table summarizes the estimated fair value of the assets acquired and liabilities and equity assumed with the Phoenix acquisition. (Dollars in thousands) Total purchase price $ 14,241 Net assets acquired: Cash and cash equivalents 11,044 Investment securities 11,331 Restricted stock 509 Loans 110,363 Bank owned life insurance 3,673 Premises and equipment 1,792 Deferred income taxes 503 Accrued interest receivable 388 Core deposit and other intangibles 578 Other assets 624 Deposits (123,238 ) FHLB borrowings (3,570 ) Accrued interest payable (32 ) Other liabilities (876 ) Preferred stock (1,750 ) 11,339 Goodwill $ 2,902
Fair Value Adjustments Made to the Amortized Cost Basis, Presented at the Fair Value of Loans Acquired	The fair value of the financial assets acquired from Phoenix included loans receivable with a gross amortized cost basis of $112,816,000. 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. (Dollars in thousands) Gross amortized cost basis at March 1, 2015 $ 112,816 Market rate adjustment 270 Credit fair value adjustment on pools of homogeneous loans (1,461 ) Credit fair value adjustment on impaired loans (1,262 ) Fair value of purchased loans at March 1, 2015 $ 110,363
Fair Value of the Loans Acquired	The information about the acquired Phoenix loans accounted for under ASC 310-30 as of March 1, 2015 is as follows: (Dollars in thousands) Contractually required principal and interest at acquisition $ 3,548 Contractual cash flows not expected to be collected (nonaccretable discount) (804 ) Expected cash flows at acquisition 2,744 Interest component of expected cash flows (accretable discount) (458 ) Fair value of acquired loans $ 2,286
Unaudited Pro Forma Information	The following table presents the unaudited pro forma information for the year ended December 31, 2015, as if the merger between Mid Penn and Phoenix had been completed on January 1, 2014. (Dollars in thousands, except per share data) Net interest income after loan loss provision $ 31,454 Noninterest income 4,152 Noninterest expense 27,817 Net income available to common shareholders 5,811 Net income per common share 1.38

Accumulated Other Comprehensi39

Accumulated Other Comprehensive (Loss) Income (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Accumulated Other Comprehensive (Loss) Income, Net of Taxes	The components of accumulated other comprehensive (loss) income, net of taxes, are as follows: (Dollars in thousands) Unrealized (Loss) Gain on Securities Defined Plan Liability Accumulated Other Comprehensive (Loss) Income Balance - December 31, 2017 $ (2,159 ) $ 85 $ (2,074 ) Balance - December 31, 2016 $ (2,919 ) $ 66 $ (2,853 )

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Securities Financing Transactions Disclosures [Abstract]
Unrealized Gain (Loss) on Investments	At December 31, 2017 and 2016, amortized cost, fair value, and unrealized gains and losses on investment securities are as follows: (Dollars in thousands) Amortized Unrealized Unrealized Fair December 31, 2017 Cost Gains Losses Value Available for sale securities: U.S. Treasury and U.S. government agencies $ 40,125 $ — $ 1,395 $ 38,730 Mortgage-backed U.S. government agencies 26,398 2 569 25,831 State and political subdivision obligations 27,775 7 739 27,043 Corporate debt securities 1,000 5 — 1,005 Equity securities 900 — 44 856 Total available for sale securities 96,198 14 2,747 93,465 Held to maturity securities: U.S. Treasury and U.S. government agencies $ 10,984 $ — $ 90 $ 10,894 Mortgage-backed U.S. government agencies 53,472 — 523 52,949 State and political subdivision obligations 36,900 41 301 36,640 Corporate debt securities — — — — Equity securities — — — — Total held to maturity securities 101,356 41 914 100,483 Total $ 197,554 $ 55 $ 3,661 $ 193,948 (Dollars in thousands) Amortized Unrealized Unrealized Fair December 31, 2016 Cost Gains Losses Value Available for sale securities: U.S. Treasury and U.S. government agencies $ 48,520 $ 34 $ 1,542 $ 47,012 Mortgage-backed U.S. government agencies 26,181 17 579 25,619 State and political subdivision obligations 61,079 91 2,332 58,838 Corporate debt securities 1,000 — — 1,000 Equity securities 1,268 — 112 1,156 $ 138,048 $ 142 $ 4,565 $ 133,625
Schedule of Fair Value and Unrealized Loss on Investments in a Continuous Unrealized Loss Position	The following table presents gross unrealized losses and fair value of investments aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31, 2017 and 2016. (Dollars in thousands) Less Than 12 Months 12 Months or More Total December 31, 2017 Number of Securities Fair Value Unrealized Losses Number of Securities Fair Value Unrealized Losses Number of Securities Fair Value Unrealized Losses Available for sale securities: U.S. Treasury and U.S. government agencies 3 $ 5,008 $ 184 18 $ 33,722 $ 1,211 21 $ 38,730 $ 1,395 Mortgage-backed U.S. government agencies 4 5,267 75 15 20,497 494 19 25,764 569 State and political subdivision obligations 11 6,144 102 40 19,091 637 51 25,235 739 Corporate debt securities 0 — — 0 — — 0 — — Equity securities 0 — — 1 506 44 1 506 44 Total temporarily impaired available for sale securities 18 16,419 361 74 73,816 2,386 92 90,235 2,747 Held to maturity securities: U.S. Treasury and U.S. government agencies 0 $ — $ — 4 $ 10,894 $ 90 4 $ 10,894 $ 90 Mortgage-backed U.S. government agencies 0 — — 35 52,949 523 35 52,949 523 State and political subdivision obligations 0 — — 77 29,976 301 77 29,976 301 Corporate debt securities 0 — — 0 — — 0 — — Equity securities 0 — — 0 — — 0 — — Total temporarily impaired held to maturity securities 0 — — 116 93,819 914 116 93,819 914 Total 18 $ 16,419 $ 361 190 $ 167,635 $ 3,300 208 $ 184,054 $ 3,661 (Dollars in thousands) Less Than 12 Months 12 Months or More Total December 31, 2016 Number of Securities Fair Value Unrealized Losses Number of Securities Fair Value Unrealized Losses Number of Securities Fair Value Unrealized Losses Available for sale securities: U.S. Treasury and U.S. government agencies 23 $ 43,698 $ 1,542 0 $ — $ — 23 $ 43,698 $ 1,542 Mortgage-backed U.S. government agencies 18 24,321 579 0 — — 18 24,321 579 State and political subdivision obligations 108 50,582 2,332 0 — — 108 50,582 2,332 Corporate debt securities 0 — — 0 — — 0 — — Equity securities 0 — — 2 1,056 112 2 1,056 112 Total temporarily impaired available for sale securities 149 $ 118,601 $ 4,453 2 $ 1,056 $ 112 151 $ 119,657 $ 4,565
Schedule of Gross Realized Gains (Losses) on Sales of Available-For-Sale Securities	Gross realized gains and losses on sales of available-for-sale securities for the years ended December 31, 2017, 2016, and 2015 are shown in the table below. (Dollars in thousands) For the year ended December 31, 2017 2016 2015 Realized gains $ 246 $ 1,927 $ 325 Realized losses (204 ) (881 ) — Net gains $ 42 $ 1,046 $ 325
Investments Classified by Contractual Maturity Date	The table below is the maturity distribution of investment securities at amortized cost and fair value at December 31, 2017. (Dollars in thousands) Available for Sale Held to Maturity Amortized Fair Amortized Fair December 31, 2017 Cost Value Cost Value Due in 1 year or less $ 100 $ 100 $ 2,001 $ 1,989 Due after 1 year but within 5 years 12,072 11,825 9,431 9,357 Due after 5 years but within 10 years 46,307 44,779 35,941 35,679 Due after 10 years 10,771 10,424 511 509 69,250 67,128 47,884 47,534 Mortgage-backed securities 26,398 25,831 53,472 52,949 Equity securities 550 506 — — $ 96,198 $ 93,465 $ 101,356 $ 100,483

Loans and Allowance for Loan 41

Loans and Allowance for Loan and Lease Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Accounts Notes Loans And Financing Receivable Gross Allowance And Net [Abstract]
Classes of the Loan Portfolio Summarized by the Aggregate Risk Rating	The classes of the loan portfolio, summarized by the aggregate pass rating, net of deferred fees and costs of $464,000 and $196,000 as of December 31, 2017 and 2016, respectively, and the classified ratings of special mention, substandard, and doubtful within Mid Penn’s internal risk rating system as of December 31, 2017 and 2016, are noted below: (Dollars in thousands) December 31, 2017 Pass Special Mention Substandard Doubtful Total Commercial and industrial $ 182,168 $ 453 $ 5,412 $ — $ 188,033 Commercial real estate 505,397 1,435 8,180 — 515,012 Commercial real estate - construction 61,667 182 487 — 62,336 Lease financing 229 — — — 229 Residential mortgage 97,814 157 1,062 — 99,033 Home equity 41,479 105 309 — 41,893 Consumer 3,868 — — — 3,868 $ 892,622 $ 2,332 $ 15,450 $ — $ 910,404 (Dollars in thousands) December 31, 2016 Pass Special Mention Substandard Doubtful Total Commercial and industrial $ 170,780 $ 937 $ 801 $ — $ 172,518 Commercial real estate 437,592 1,683 7,249 — 446,524 Commercial real estate - construction 52,888 202 1,286 — 54,376 Lease financing 425 — — — 425 Residential mortgage 97,994 107 1,356 — 99,457 Home equity 37,242 142 224 — 37,608 Consumer 3,016 — — — 3,016 $ 799,937 $ 3,071 $ 10,916 $ — $ 813,924
Impaired Loans by Loan Portfolio Class	Impaired loans by loan portfolio class as of December 31, 2017 and 2016 are summarized as follows: December 31, 2017 December 31, 2016 (Dollars in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With no related allowance recorded: Commercial and industrial $ — $ 13 $ — $ 4 $ 9 $ — Commercial real estate 3,424 4,056 — 726 1,792 — Commercial real estate - construction — — — 618 618 — Lease financing — — — — — — Residential mortgage 760 877 — 848 882 — Home equity 260 295 — 111 129 — Consumer — — — — — — With no related allowance recorded and acquired with credit deterioration: Commercial and industrial $ — $ — $ — $ — $ — $ — Commercial real estate 555 555 — 842 842 — Commercial real estate - construction — — — — — — Lease financing — — — — — — Residential mortgage 306 306 — 389 389 — Home equity — — — — — — Consumer — — — — — — With an allowance recorded: Commercial and industrial $ 4,434 $ 4,460 $ 136 $ 56 $ 62 $ 6 Commercial real estate 1,423 1,589 293 2,520 2,646 711 Commercial real estate - construction 487 492 100 242 242 72 Lease financing — — — — — — Residential mortgage — — — 68 68 68 Home equity — — — 29 49 1 Consumer — — — — — — Total: Commercial and industrial $ 4,434 $ 4,473 $ 136 $ 60 $ 71 $ 6 Commercial real estate 5,402 6,200 293 4,088 5,280 711 Commercial real estate - construction 487 492 100 860 860 72 Lease financing — — — — — — Residential mortgage 1,066 1,183 — 1,305 1,339 68 Home equity 260 295 — 140 178 1
Average Recorded Investment Of Impaired Loans And Related Interest Income By Loan Portfolio Class	The average recorded investment of impaired loans and related interest income recognized for the years ended December 31, 2017, 2016, and 2015 are summarized as follows: December 31, 2017 December 31, 2016 December 31, 2015 (Dollars in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With no related allowance recorded: Commercial and industrial $ 15 $ — $ 9 $ — $ 19 $ — Commercial real estate 1,915 279 820 — 1,051 14 Commercial real estate - construction 164 — 124 — — — Lease financing — — — — — — Residential mortgage 890 18 821 21 816 8 Home equity 218 6 75 — 107 — Consumer — — — — — — With no related allowance recorded and acquired with credit deterioration: Commercial and industrial $ — $ — $ — $ — $ — $ 205 Commercial real estate 651 110 810 164 926 350 Commercial real estate - construction — — — — — — Lease financing — — — — — — Residential mortgage 332 — 378 4 400 — Home equity — — — — — 3 Consumer — — — — — — With an allowance recorded: Commercial and industrial $ 1,779 $ — $ 59 $ — $ 123 $ — Commercial real estate 1,446 — 2,177 — 1,721 — Commercial real estate - construction 488 — 48 — — — Lease financing — — — — — — Residential mortgage — — 14 — 25 — Home equity — — 32 — — — Consumer — — — — — — Total: Commercial and industrial $ 1,794 $ — $ 68 $ — $ 142 $ 205 Commercial real estate 4,012 389 3,807 164 3,698 364 Commercial real estate - construction 652 — 172 — — — Lease financing — — — — — — Residential mortgage 1,222 18 1,213 25 1,241 8 Home equity 218 6 107 — 107 3
Non-accrual Loans by Classes of the Loan Portfolio	Nonaccrual loans by loan portfolio class as of December 31, 2017 and 2016 are summarized as follows: (Dollars in thousands) 2017 2016 Commercial and industrial $ 4,434 $ 4 Commercial real estate 4,902 2,939 Commercial real estate - construction 487 860 Residential mortgage 492 715 Home equity 260 140 $ 10,575 $ 4,658
Loan Portfolio Summarized by the Past Due Status	The classes of the loan portfolio summarized by the past due status as of December 31, 2017 and 2016 are summarized as follows: (Dollars in thousands) December 31, 2017 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days Total Past Due Current Total Loans Loans Receivable > 90 Days and Accruing Commercial and industrial: Commercial and industrial $ 4,439 $ 16 $ — $ 4,455 $ 183,578 $ 188,033 $ — Commercial real estate: Commercial real estate — — 3,669 3,669 510,788 514,457 — Acquired with credit deterioration 500 — 55 555 - 555 — Commercial real estate - construction: Commercial real estate - construction — — 487 487 61,849 62,336 — Lease financing: Lease financing — — — — 229 229 — Residential mortgage: Residential mortgage 310 467 177 954 97,773 98,727 — Acquired with credit deterioration — 31 193 224 82 306 — Home equity: Home equity 54 98 250 402 41,491 41,893 — Consumer: Consumer 3 — — 3 3,865 3,868 — Total $ 5,306 $ 612 $ 4,831 $ 10,749 $ 899,655 $ 910,404 $ — (Dollars in thousands) December 31, 2016 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days Total Past Due Current Total Loans Loans Receivable > 90 Days and Accruing Commercial and industrial: Commercial and industrial $ 164 $ 12 $ 4 $ 180 $ 172,338 $ 172,518 $ — Commercial real estate: Commercial real estate 475 — 1,004 1,479 444,203 445,682 — Acquired with credit deterioration — — 59 59 783 842 59 Commercial real estate - construction: Commercial real estate - construction — 404 84 488 53,888 54,376 — Lease financing: Lease financing — — — — 425 425 — Residential mortgage: Residential mortgage 548 124 237 909 98,159 99,068 — Acquired with credit deterioration — — 238 238 151 389 — Home equity: Home equity 33 13 125 171 37,437 37,608 — Consumer: Consumer — — — — 3,016 3,016 — Total $ 1,220 $ 553 $ 1,751 $ 3,524 $ 810,400 $ 813,924 $ 59
Allowance for Loan Losses and Recorded Investment in Financing Receivables	Activity in the allowance for loan and lease losses for the years ended December 31, 2017, 2016, and 2015, and the recorded investment in loans receivable as of December 31, 2017, 2016, and 2015 are as follows: (Dollars in thousands) December 31, 2017 Commercial and industrial Commercial real estate Commercial real estate - construction Lease financing Residential mortgage Home equity Consumer Unallocated Total Allowance for loan and lease losses: Beginning balance $ 1,580 $ 4,323 $ 144 $ 1 $ 541 $ 379 $ 3 $ 212 $ 7,183 Charge-offs (25 ) (322 ) — — (102 ) (20 ) (28 ) — (497 ) Recoveries 26 553 — — 4 5 7 — 595 Provisions 214 (119 ) 34 (1 ) (15 ) 59 21 132 325 Ending balance 1,795 4,435 178 — 428 423 3 344 7,606 Ending balance: individually evaluated for impairment 136 293 100 — — — — — 529 Ending balance: collectively evaluated for impairment $ 1,659 $ 4,142 $ 78 $ - $ 428 $ 423 $ 3 $ 344 $ 7,077 Loans receivable: Ending balance $ 188,033 $ 515,012 $ 62,336 $ 229 $ 99,033 $ 41,893 $ 3,868 $ — $ 910,404 Ending balance: individually evaluated for impairment 4,434 4,847 487 — 760 260 — — 10,788 Ending balance: acquired with credit deterioration — 555 — — 306 — — — 861 Ending balance: collectively evaluated for impairment $ 183,599 $ 509,610 $ 61,849 $ 229 $ 97,967 $ 41,633 $ 3,868 $ — $ 898,755 (Dollars in thousands) December 31, 2016 Commercial and industrial Commercial real estate Commercial real estate - construction Lease financing Residential mortgage Home equity Consumer Unallocated Total Allowance for loan and lease losses: Beginning balance $ 1,393 $ 3,552 $ 153 $ 1 $ 534 $ 317 $ 12 $ 206 $ 6,168 Charge-offs (820 ) (216 ) — — (4 ) (25 ) (42 ) — (1,107 ) Recoveries 4 211 — — 26 - 11 — 252 Provisions 1,003 776 (9 ) - (15 ) 87 22 6 1,870 Ending balance 1,580 4,323 144 1 541 379 3 212 7,183 Ending balance: individually evaluated for impairment 6 711 72 — 68 1 — — 858 Ending balance: collectively evaluated for impairment $ 1,574 $ 3,612 $ 72 $ 1 $ 473 $ 378 $ 3 $ 212 $ 6,325 Loans receivable: Ending balance $ 172,518 $ 446,524 $ 54,376 $ 425 $ 99,457 $ 37,608 $ 3,016 $ — $ 813,924 Ending balance: individually evaluated for impairment 60 3,246 860 — 916 140 — — 5,222 Ending balance: acquired with credit deterioration — 842 — — 389 — — — 1,231 Ending balance: collectively evaluated for impairment $ 172,458 $ 442,436 $ 53,516 $ 425 $ 98,152 37,468 $ 3,016 $ — $ 807,471 (Dollars in thousands) December 31, 2015 Commercial and industrial Commercial real estate Commercial real estate - construction Lease financing Residential mortgage Home equity Consumer Unallocated Total Allowance for loan and lease losses: Beginning Balance $ 1,393 $ 3,925 $ 33 $ 2 $ 450 $ 653 $ 35 $ 225 $ 6,716 Charge-offs (130 ) (1,569 ) — — (35 ) (36 ) (14 ) — (1,784 ) Recoveries 12 75 — — 44 29 11 — 171 Provisions 118 1,121 120 (1 ) 75 (329 ) (20 ) (19 ) 1,065 Ending balance 1,393 3,552 153 1 534 317 12 206 6,168 Ending balance: individually evaluated for impairment 51 429 — — 23 — — — 503 Ending balance: collectively evaluated for impairment $ 1,342 $ 3,123 $ 153 $ 1 $ 511 $ 317 $ 12 $ 206 $ 5,665 Loans receivable: Ending balance $ 160,261 $ 369,464 $ 68,068 $ 727 $ 100,665 $ 33,411 $ 3,917 $ — $ 736,513 Ending balance: individually evaluated for impairment 127 2,970 — — 1,361 115 — — 4,573 Ending balance: acquired with credit deterioration — 931 — — 400 — — — 1,331 Ending balance: collectively evaluated for impairment $ 160,134 $ 365,563 $ 68,068 $ 727 $ 98,904 33,296 $ 3,917 $ — $ 730,609
Troubled Debt Restructurings	The recorded investments in troubled debt restructured loans at December 31, 2017 and 2016 are as follows: (Dollars in thousands) Pre-Modification Post-Modification December 31, 2017 Outstanding Investment Outstanding Recorded Investment Recorded Investment Commercial and industrial $ 4,110 $ 4,460 $ 4,434 Commercial real estate 5,735 5,581 4,593 Residential mortgage 691 689 544 $ 10,536 $ 10,730 $ 9,571 (Dollars in thousands) Pre-Modification Post-Modification December 31, 2016 Outstanding Recorded Investment Outstanding Recorded Investment Recorded Investment Commercial and industrial $ 40 $ 35 $ 5 Commercial real estate 4,569 4,031 2,871 Residential mortgage 759 757 639 $ 5,368 $ 4,823 $ 3,515
Schedule of Troubled Debt Restructurings Modified in the Period	The following table summarizes the loans whose terms have been modified resulting in troubled debt restructurings during the year ended December 31, 2017. (Dollars in thousands) Pre-Modification Post-Modification December 31, 2017 Number of Contracts Outstanding Recorded Investment Outstanding Recorded Investment Recorded Investment Commercial and industrial 1 $ 4,110 $ 4,460 $ 4,434 Commercial real estate 9 3,212 3,150 3,140 10 $ 7,322 $ 7,610 $ 7,574
Schedule of Accretion of Purchased Impaired Loan	The following table provides activity for the accretable yield of purchased impaired loans for the year ended December 31, 2017. (Dollars in thousands) Accretable yield, January 1, 2017 $ 67 Accretable yield amortized to interest income (23 ) Reclassification from nonaccretable difference (a) 23 Accretable yield, December 31, 2017 $ 67 (a) Reclassification from non-accretable difference represents an increase to the estimated cash flows to be collected on the underlying portfolio.

Bank Premises and Equipment (Ta

Bank Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Premises and Equipment	At December 31, 2017 and 2016, bank premises and equipment are as follows: (Dollars in thousands) 2017 2016 Land $ 3,564 $ 2,315 Buildings 8,632 9,517 Furniture, fixtures, and equipment 8,262 8,184 Leasehold improvements 1,126 1,432 Construction in progress 4,467 89 Total cost 26,051 21,537 Less accumulated depreciation (9,883 ) (10,463 ) Net book value of bank premises and equipment 16,168 11,074 Assets held for sale - 1,894 Total bank premises and equipment $ 16,168 $ 12,968
Schedule of Future Minimum Rental Payments of Operating Leases	The following summary reflects the future minimum rental payments by year under Mid Penn’s operating leases as of December 31, 2017, including a breakdown of the sublease rental income and future minimum payments owed to related parties. (Dollars in thousands) Lease Obligation Sublease Rental Income Net Rental Expense 2018 1,171 79 1,092 2019 975 81 894 2020 790 81 709 2021 617 20 597 2022 564 — 564 thereafter 5,113 — 5,113 $ 9,230 $ 261 $ 8,969

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Time Deposits By Maturity Date	Time deposits at December 31, 2017, mature as follows: (Dollars in thousands) Time Deposits Less than $250,000 $250,000 or more Maturing in 2018 $ 74,304 $ 29,736 Maturing in 2019 38,810 4,811 Maturing in 2020 24,380 885 Maturing in 2021 16,987 309 Maturing in 2022 8,984 1,452 Maturing thereafter 965 — $ 164,430 $ 37,193

Long-term Debt (Tables)

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Maturities Of Long Term Debt [Abstract]
Long-term Debt Outstanding by Maturity Date	As of December 31, 2017 and 2016, the Bank had long-term debt outstanding in the amount of $12,352,000 and $13,581,000, respectively, consisting of: (Dollars in thousands) At December 31, 2017 2016 Loans maturing in 2017 at a rate of 3.03% $ — $ 1,016 Loan maturing in 2019 at a rate of 1.87% 10,000 10,000 Loan maturing in 2026 at a rate of 4.80% 2,295 2,504 Loan maturing in 2027 at a rate of 6.71% 57 61 $ 12,352 $ 13,581

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Assets Measured at Fair Value on a Recurring Basis	The following tables illustrate the assets measured at fair value on a recurring basis segregated by hierarchy fair value levels: Fair value measurements at December 31, 2017 using: (Dollars in thousands) Total carrying value at Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Assets: December 31, 2017 (Level 1) (Level 2) (Level 3) U.S. Treasury and U.S. government agencies $ 38,730 $ — $ 38,730 $ — Mortgage-backed U.S. government agencies 25,831 — $ 25,831 — State and political subdivision obligations 27,043 — $ 27,043 — Corporate debt securities 1,005 — $ 1,005 — Equity securities 856 856 — — $ 93,465 $ 856 $ 92,609 $ — Fair value measurements at December 31, 2016 using: (Dollars in thousands) Total carrying value at Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Assets: December 31, 2016 (Level 1) (Level 2) (Level 3) U.S. Treasury and U.S. government agencies $ 47,012 $ 1,864 $ 45,148 $ — Mortgage-backed U.S. government agencies 25,619 — 25,619 — State and political subdivision obligations 58,838 — 58,838 — Corporate debt securities 1,000 — 1,000 — Equity securities 1,156 1,056 100 — $ 133,625 $ 2,920 $ 130,705 $ —
Fair Value Measurements, Nonrecurring	The following tables illustrate the assets measured at fair value on a nonrecurring basis segregated by hierarchy fair value levels. Fair value measurements at December 31, 2017 using: (Dollars in thousands) Total carrying value at Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Assets: December 31, 2017 (Level 1) (Level 2) (Level 3) Impaired Loans $ 6,090 $ — $ — $ 6,090 Foreclosed Assets Held for Sale — — — — Mortgage Servicing Rights 126 — — 126 Fair value measurements at December 31, 2016 using: (Dollars in thousands) Total carrying value at Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Assets: December 31, 2016 (Level 1) (Level 2) (Level 3) Impaired Loans $ 2,404 $ — $ — $ 2,404 Foreclosed Assets Held for Sale 135 — — 135 Mortgage Servicing Rights 144 — — 144
Fair Value Inputs, Assets, Quantitative Information	The following tables present additional quantitative information about assets measured at fair value on a nonrecurring basis and for which Mid Penn has utilized Level 3 inputs to determine the fair value. (Dollars in thousands) Quantitative Information about Level 3 Fair Value Measurements December 31, 2017 Fair Value Estimate Valuation Technique Unobservable Input Range Weighted Average Impaired Loans $ 6,090 Appraisal of collateral (a) Appraisal adjustments (b) 6% - 51% 28% Foreclosed Assets Held for Sale — Appraisal of collateral (a), (c) Appraisal adjustments (b) 0% - 0% 0% Mortgage Servicing Rights 126 Multiple of annual service fee Estimated prepayment speed based on rate and term 70% - 100% 98% (Dollars in thousands) Quantitative Information about Level 3 Fair Value Measurements December 31, 2016 Fair Value Estimate Valuation Technique Unobservable Input Range Weighted Average Impaired Loans $ 2,404 Appraisal of collateral (a) Appraisal adjustments (b) 11% - 70% 30% Foreclosed Assets Held for Sale 135 Appraisal of collateral (a), (c) Appraisal adjustments (b) 26% - 31% 27% Mortgage Servicing Rights 144 Multiple of annual service fee Estimated prepayment speed based on rate and term 70% - 100% 98% (a) Fair value is generally determined through independent 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 percent 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, or age of the appraisal. (c) Includes qualitative adjustments by management and estimated liquidation expenses.
Fair Value, by Balance Sheet Grouping	The following table summarizes the carrying value and fair value of financial instruments at December 31, 2017 and 2016. (Dollars in thousands) December 31, 2017 December 31, 2016 Carrying Fair Carrying Fair Value Value Value Value Financial assets: Cash and cash equivalents $ 23,514 $ 23,514 $ 45,973 $ 45,973 Available for sale investment securities 93,465 93,465 133,625 133,625 Held to maturity investment securities 101,356 100,483 — — Net loans and leases 902,798 917,081 806,741 824,293 Restricted investment in bank stocks 4,384 4,384 2,443 2,443 Accrued interest receivable 4,564 4,564 3,928 3,928 Mortgage servicing rights 126 126 144 144 Financial liabilities: Deposits $ 1,023,568 $ 1,026,830 $ 935,373 $ 935,075 Short-term borrowings 34,611 34,611 — — Long-term debt 12,352 11,692 13,581 13,614 Subordinated debt 17,338 17,358 7,414 7,534 Accrued interest payable 645 645 515 515 Off-balance sheet financial instruments: Commitments to extend credit $ — $ — $ — $ — Financial standby letters of credit — — — —
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following presents the carrying amount, fair value, and placement in the fair value hierarchy of Mid Penn’s financial instruments as of December 31, 2017 and 2016. Carrying values approximate fair values for cash and cash equivalents, interest-bearing time balances with other financial institutions, restricted investment in bank stocks, accrued interest receivable and payable, and short-term borrowings. Other than cash and cash equivalents, which are considered Level 1 Inputs, these instruments are Level 2 Inputs. The following tables exclude financial instruments for which the placement in the fair value hierarchy has been disclosed elsewhere or for which the carrying amount approximates fair value. Fair Value Measurements (Dollars in thousands) Quoted Prices Significant in Active Markets Other Significant for Identical Assets Observable Unobservable Carrying Fair or Liabilities Inputs Inputs December 31, 2017 Amount Value (Level 1) (Level 2) (Level 3) Financial instruments - assets Net loans and leases $ 902,798 $ 917,081 $ — $ — $ 917,081 Financial instruments - liabilities Deposits $ 1,023,568 $ 1,026,830 $ — $ 1,026,830 $ — Long-term debt 12,352 11,692 — 11,692 — Subordinated debt 17,338 17,358 — — 17,358 Fair Value Measurements (Dollars in thousands) Quoted Prices Significant in Active Markets Other Significant for Identical Observable Unobservable Carrying Fair or Liabilities Inputs Inputs December 31, 2016 Amount Value (Level 1) (Level 2) (Level 3) Financial instruments - assets Net loans and leases $ 806,741 $ 824,293 $ — $ — $ 824,293 Financial instruments - liabilities Deposits $ 935,373 $ 935,075 $ — $ 935,075 $ — Long-term debt 13,581 13,614 — 13,614 — Subordinated debt 7,414 7,534 — — 7,534

Postretirement Benefit Plans (T

Postretirement Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Postretirement Health And Life Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Funded Status	The following tables provide a reconciliation of the changes in the plan’s health and life insurance benefit obligations and fair value of plan assets for the years ended December 31, 2017 and 2016, and a statement of the funded status at December 31, 2017 and 2016. (Dollars in thousands) December 31, Change in benefit obligations: 2017 2016 Benefit obligations, January 1 $ 540 $ 572 Service cost 4 4 Interest cost 20 23 Change in experience (11 ) 2 Change in assumptions 20 13 Change due to plan amendment — — Benefit payments (65 ) (74 ) Benefit obligations, December 31 $ 508 $ 540 Change in fair value of plan assets: Fair value of plan assets, January 1 $ — $ — Employer contributions 65 74 Benefit payments (65 ) (74 ) Fair value of plan assets, December 31 $ — $ — Funded status at year end $ (508 ) $ (540 )
Schedule of Amounts Recognized in Balance Sheet	The amount recognized in the consolidated balance sheets at December 31, 2017 and 2016, is as follows: (Dollars in thousands) 2017 2016 Accrued benefit liability $ 508 $ 540
Schedule of Amounts Recognized in Other Comprehensive (Loss) Income	The amounts recognized in accumulated other comprehensive loss consist of: (Dollars in thousands) December 31, 2017 2016 Net gain, pretax $ (22 ) $ (31 ) Net prior service cost, pretax (174 ) (209 )
Schedule of Net Periodic Benefit (Income) Costs	The components of net periodic postretirement benefit (income) cost for 2017, 2016 and 2015 are as follows: (Dollars in thousands) 2017 2016 2015 Service cost $ 4 $ 4 $ 13 Interest cost 20 23 32 Amortization of prior service cost (35 ) (35 ) - Net periodic postretirement benefit (income) cost $ (11 ) $ (8 ) $ 45
Schedule of Assumptions Used	Assumptions used in the measurement of Mid Penn’s benefit obligations at December 31, 2017 and 2016 are as follows: Weighted-average assumptions: 2017 2016 Discount rate 3.50 % 4.00 % Rate of compensation increase 2.50 % 3.00 % Assumptions used in the measurement of Mid Penn’s net periodic benefit cost for the years ended December 31, 2017, 2016 and 2015 are as follows: Weighted-average assumptions: 2017 2016 2015 Discount rate 4.00 % 4.25 % 4.00 % Rate of compensation increase 3.00 % 3.25 % 3.00 %
Schedule of Health Care Cost Trend Rates	Assumed health care cost trend rates at December 31, 2017, 2016 and 2015 are as follows: 2017 2016 2015 Health care cost trend rate assumed for next year 6.00 % 6.00 % 5.50 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 5.40 % 5.50 % 5.50 % Year that the rate reaches the ultimate trend rate 2024 2018 2016
Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates	Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plans. At December 31, 2017, a one-percentage-point change in assumed health care cost trend rates would have the following effects: (Dollars in thousands) One-Percentage Point Increase Decrease Effect on total of service and interest cost $ — $ 2 Effect on accumulated postretirement benefit obligation 3 4
Schedule of Expected Benefit Payments	Mid Penn expects to contribute $60,000 to its life and health benefit plans in 2018. The following table shows the estimated benefit payments for future periods. (Dollars in thousands) 1/1/2018 to 12/31/2018 $ 60 1/1/2019 to 12/31/2019 61 1/1/2020 to 12/31/2020 55 1/1/2021 to 12/31/2021 31 1/1/2022 to 12/31/2022 32 1/1/2023 to 12/31/2027 160
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Funded Status	The following tables provide a reconciliation of the changes in the directors’ defined benefit plan’s benefit obligations and fair value of plan assets for the years ended December 31, 2017 and 2016, and a statement of the status at December 31, 2017 and 2016. This Plan is unfunded. (Dollars in thousands) December 31, Change in benefit obligations: 2017 2016 Benefit obligations, January 1 $ 1,122 $ 1,150 Service cost 35 34 Interest cost 43 46 Actuarial gain (loss) 6 (13 ) Change in assumptions 2 (4 ) Benefit payments (92 ) (91 ) Benefit obligations, December 31 $ 1,116 $ 1,122 Change in fair value of plan assets: Fair value of plan assets, January 1 $ — $ — Employer contributions 92 91 Benefit payments (92 ) (91 ) Fair value of plan assets, December 31 $ — $ — Funded status at year end $ (1,116 ) $ (1,122 )
Schedule of Amounts Recognized in Balance Sheet	Amounts recognized in the consolidated balance sheet at December 31, 2017 and 2016 are as follows: (Dollars in thousands) 2017 2016 Accrued benefit liability $ 1,116 $ 1,122
Schedule of Amounts Recognized in Other Comprehensive (Loss) Income	Amounts recognized in accumulated other comprehensive loss consist of: (Dollars in thousands) December 31, 2017 2016 Net prior service cost, pretax $ 22 $ 43 Net loss, pretax 67 60
Schedule of Net Periodic Benefit (Income) Costs	The components of net periodic retirement cost for 2017, 2016 and 2015 are as follows: (Dollars in thousands) 2017 2016 2015 Service cost $ 35 $ 34 $ 33 Interest cost 43 46 45 Amortization of prior-service cost 22 22 22 Net periodic retirement cost $ 100 $ 102 $ 100
Schedule of Assumptions Used	Assumptions used in the measurement of Mid Penn’s benefit obligations at December 31, 2017 and 2016 are as follows: Weighted-average assumptions: 2017 2016 Discount rate 3.50 % 4.00 % Change in consumer price index 1.50 % 2.00 % Assumptions used in the measurement of Mid Penn’s net periodic benefit cost for the years ended December 31, 2017, 2016 and 2015 are as follows: Weighted-average assumptions: 2017 2016 2015 Discount rate 4.00 % 4.25 % 4.00 % Change in consumer price index 2.00 % 2.25 % 2.25 %
Schedule of Expected Benefit Payments	Mid Penn expects to contribute $95,000 to its retirement plan in 2018. The following table shows the estimated benefit payments for future periods. (Dollars in thousands) 1/1/2018 to 12/31/2018 $ 95 1/1/2019 to 12/31/2019 95 1/1/2020 to 12/31/2020 96 1/1/2021 to 12/31/2021 107 1/1/2022 to 12/31/2022 104 1/1/2023 to 12/31/2027 413

Other Benefit Plans (Tables)

Other Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Schedule of Employees Eligible to Participate in Employee Stock Purchase Plan	Mid Penn has an Employee Stock Purchase Plan (“ESPP”) in which all employees are eligible to participate. The plan allows employees to use a portion of their salaries and wages to purchase common shares of Mid Penn stock at the market value of shares at the end of each calendar quarter. 2017 2016 2015 ESPP shares purchased 3,578 4,465 4,162 Average purchase price per share $ 29.027 $ 18.520 $ 15.865

Federal Income Taxes (Tables)

Federal Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net Deferred Tax Asset	The following temporary differences gave rise to the net deferred tax asset at December 31, 2017 and 2016. (Dollars in thousands) 2017 2016 Deferred tax assets: Allowance for loan and lease losses $ 1,597 $ 2,442 Loan fees 105 82 Deferred compensation 221 341 Benefit plans 320 565 Unrealized loss on securities 574 1,504 Nonaccrual interest — 955 Business combination adjustments 358 720 Sale/leaseback adjustment 72 — Other 108 177 3,355 6,786 Deferred tax liabilities: Depreciation (619 ) (1,175 ) Bond accretion (9 ) (117 ) Goodwill and intangibles (329 ) (500 ) Prepaid expenses (333 ) (312 ) Business combination adjustments (176 ) (367 ) Other (1 ) (29 ) (1,467 ) (2,500 ) Deferred tax asset, net $ 1,888 $ 4,286
Provision for Income Taxes	The provision for income taxes consists of the following: (Dollars in thousands) 2017 2016 2015 Current expense $ 2,672 $ 2,613 $ 647 Deferred expense (benefit) 1,828 (336 ) 997 Total provision for income taxes $ 4,500 $ 2,277 $ 1,644
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of income tax at the statutory rate of 34% to Mid Penn's effective rate is as follows: (Dollars in thousands) 2017 2016 2015 Provision at the expected statutory rate $ 3,940 $ 3,428 $ 2,779 Effect of tax-exempt income (668 ) (1,089 ) (1,105 ) Effect of investment in life insurance (89 ) (90 ) (91 ) Nondeductible interest 30 41 37 Nondeductible merger and acquisition expense 191 — 34 Rate change adjustment 1,169 — — Other items (73 ) (13 ) (10 ) Provision for income taxes $ 4,500 $ 2,277 $ 1,644

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Regulatory Capital Levels And Related Ratios	Mid Penn maintained the following regulatory capital levels, leverage ratios, and risk-based capital ratios as of December 31, 2017, and December 31, 2016, as follows: (Dollars in thousands) Capital Adequacy To Well-Capitalized Under Prompt Minimum Capital Corrective Actual Required (1) Action Provisions Amount Ratio Amount Ratio Amount Ratio Corporation As of December 31, 2017 Tier 1 Capital (to Average Assets) $ 74,417 6.5 % $ 45,857 4.00 % $ N/A N/A Common Equity Tier 1 Capital (to Risk Weighted Assets) 74,417 8.4 % 50,661 5.75 % N/A N/A Tier 1 Capital (to Risk Weighted Assets) 74,417 8.4 % 63,877 7.25 % N/A N/A Total Capital (to Risk Weighted Assets) 99,466 11.3 % 81,498 9.25 % N/A N/A Bank As of December 31, 2017 Tier 1 Capital (to Average Assets) $ 88,294 7.7 % $ 45,846 4.00 % $ 57,308 5.0 % Common Equity Tier 1 Capital (to Risk Weighted Assets) 88,294 10.0 % 50,661 5.75 % 57,269 6.5 % Tier 1 Capital (to Risk Weighted Assets) 88,294 10.0 % 63,877 7.25 % 70,485 8.0 % Total Capital (to Risk Weighted Assets) 96,005 10.9 % 81,498 9.25 % 88,106 10.0 % Corporation As of December 31, 2016 Tier 1 Capital (to Average Assets) $ 70,431 6.8 % $ 41,595 4.00 % $ N/A N/A Common Equity Tier 1 Capital (to Risk Weighted Assets) 70,431 9.1 % 39,641 5.125 % N/A N/A Tier 1 Capital (to Risk Weighted Assets) 70,431 9.1 % 51,244 6.625 % N/A N/A Total Capital (to Risk Weighted Assets) 85,148 11.0 % 66,714 8.625 % N/A N/A Bank As of December 31, 2016 Tier 1 Capital (to Average Assets) $ 77,026 7.4 % $ 41,568 4.00 % $ 51,960 5.0 % Common Equity Tier 1 Capital (to Risk Weighted Assets) 77,026 10.0 % 39,611 5.125 % 50,239 6.5 % Tier 1 Capital (to Risk Weighted Assets) 77,026 10.0 % 51,205 6.625 % 61,832 8.0 % Total Capital (to Risk Weighted Assets) 84,329 10.9 % 66,663 8.625 % 77,291 10.0 % (1) Minimum amounts and ratios as of December 31, 2017 include the second year phase in of the capital conservation buffer of 1.25 percent required by the Basel III framework. At December 31, 2016, the minimum amounts and ratios included the first year phase in of the capital conservation buffer of 0.625 percent required by the Basel III framework.

Common Stock (Tables)

Common Stock (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Compensation Expense and Related Tax Benefits for Restricted Stock Awards Recognized	Share-based compensation expense relating to restricted stock is recognized on a straight-line basis over the vesting periods of the awards and is a component of salaries and benefits expense. Restricted shares granted to employees vest in equal amounts on the anniversary of the grant date over a four year vesting period. Restricted shares granted to directors have a twelve month vesting period. The following table presents compensation expense and related tax benefits for restricted stock awards recognized on the consolidated statement of income. (Dollars in thousands) 2017 2016 2015 Compensation expense $ 145 $ 53 $ 28 Tax benefit (49 ) (18 ) (10 ) Net income effect $ 96 $ 35 $ 18
Schedule of Non-Vested Restricted Stock	The following table presents information regarding the non-vested restricted stock for the year ended December 31, 2017. Shares Weighted-Average Grant Date Fair Value Non-vested at January 1, 2017 13,055 $ 17.66 Vested (3,996 ) 17.38 Cancelled — — Granted 10,440 26.65 Non-vested at December 31, 2017 19,499 22.54

Parent Company Statements (Tabl

Parent Company Statements (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheets	CONDENSED BALANCE SHEETS (Dollars in thousands) December 31, 2017 2016 ASSETS Cash and cash equivalents $ 4,686 $ 780 Equity investments — 545 Investment in subsidiaries 89,581 77,029 Other assets — 40 Total assets $ 94,267 $ 78,394 LIABILITIES AND SHAREHOLDERS' EQUITY Subordinated debt $ 17,338 $ 7,414 Other liabilities 1,226 513 Shareholders' equity 75,703 70,467 Total liabilities and shareholders' equity $ 94,267 $ 78,394
Condensed Statements of Income and Comprehensive Income	CONDENSED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (Dollars in thousands) For Years Ended December 31, 2017 2016 2015 Income Dividends from subsidiaries $ 9,657 $ 2,871 $ 5,662 Other income 19 33 19 Total Income 9,676 2,904 5,681 Expense Other expenses (1,899 ) (606 ) (695 ) Total Expense (1,899 ) (606 ) (695 ) Income before income tax and equity in undistributed (loss) earnings of subsidiaries 7,777 2,298 4,986 Equity in undistributed (loss) earnings of subsidiaries (1,136 ) 5,311 1,346 Income before income tax 6,641 7,609 6,332 Income tax benefit 448 195 196 Net income 7,089 7,804 6,528 Series B preferred stock dividends and redemption premium — — 473 Series C preferred stock dividends — — 17 Net income available to common shareholders $ 7,089 $ 7,804 $ 6,038 Comprehensive income $ 8,209 $ 3,139 $ 6,827
Condensed Statement of Cash Flows	CONDENSED STATEMENTS OF CASH FLOWS (Dollars in thousands) For Years Ended December 31, 2017 2016 2015 CASH FLOWS FROM OPERATING ACTIVITIES Net income $ 7,089 $ 7,804 $ 6,528 Equity in undistributed loss (earnings) of subsidiaries 1,136 (5,311 ) (1,346 ) Decrease (increase) in other assets 240 59 (14 ) Increase (decrease) in other liabilities 626 457 (665 ) Net cash provided by operating activities 9,091 3,009 4,503 CASH FLOWS FROM INVESTING ACTIVITIES Net cash paid for acquisition — — (2,949 ) Proceeds from the sale of investment securities 618 — — Investment in subsidiary (12,600 ) — — Net cash used in investing activities (11,982 ) — (2,949 ) CASH FLOWS FROM FINANCING ACTIVITIES Dividends paid (3,264 ) (2,875 ) (2,175 ) Series B preferred stock redemption premium — — (100 ) Series B preferred stock redemption — — (5,000 ) Series C preferred stock redemption — — (1,750 ) Employee Stock Purchase Plan 104 82 66 Director Stock Purchase Plan 42 — — Deferred financing fees paid for subordinated debt issuance (85 ) — (85 ) Subordinated debt issuance 10,000 — 7,500 Net cash provided by (used in) financing activities 6,797 (2,793 ) (1,544 ) Net increase in cash and cash equivalents 3,906 216 10 Cash and cash equivalents, beginning of year 780 564 554 Cash and cash equivalents, end of year $ 4,686 $ 780 $ 564

Summary of Quarterly Consolid52

Summary of Quarterly Consolidated Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Data [Abstract]
Quarterly Condensed Financials	The following table presents summarized quarterly financial data for 2017 and 2016. (Dollars in thousands, except per share data) 2017 Quarter Ended March 31 June 30 September 30 December 31 Interest Income $ 10,559 $ 10,879 $ 11,150 $ 11,304 Interest Expense 1,384 1,469 1,634 1,817 Net Interest Income 9,175 9,410 9,516 9,487 Provision for Loan and Lease Losses 125 100 — 100 Net Interest Income After Provision for Loan Losses 9,050 9,310 9,516 9,387 Noninterest Income 1,436 1,362 1,564 1,331 Noninterest Expense 7,802 7,558 7,960 8,047 Income Before Provision for Income Taxes 2,684 3,114 3,120 2,671 Provision for Income Taxes 690 769 871 2,170 Net Income Available to Common Shareholders $ 1,994 $ 2,345 $ 2,249 $ 501 Per Share Data: Basic Earnings Per Common Share $ 0.47 $ 0.55 $ 0.53 $ 0.12 Cash Dividends Declared 0.13 0.13 0.13 0.38 (Dollars in thousands, except per share data) 2016 Quarter Ended March 31 June 30 September 30 December 31 Interest Income $ 9,697 $ 9,859 $ 10,125 $ 10,531 Interest Expense 1,282 1,316 1,367 1,402 Net Interest Income 8,415 8,543 8,758 9,129 Provision for Loan and Lease Losses 340 395 585 550 Net Interest Income After Provision for Loan Losses 8,075 8,148 8,173 8,579 Noninterest Income 1,232 1,398 1,419 1,875 Noninterest Expense 6,982 6,931 7,165 7,740 Income Before Provision for Income Taxes 2,325 2,615 2,427 2,714 Provision for Income Taxes 520 593 526 638 Net Income Available to Common Shareholders $ 1,805 $ 2,022 $ 1,901 $ 2,076 Per Share Data: Basic Earnings Per Common Share $ 0.43 $ 0.48 $ 0.45 $ 0.49 Cash Dividends Declared 0.22 0.12 0.12 0.22

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017Segment
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of reportable segments	1

Nature of Business (Narrative)

Nature of Business (Narrative) (Details)	Dec. 31, 2017Store
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of offices	23

Summary of Significant Accoun55

Summary of Significant Accounting Policies (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net gain on sales of investment securities		$ 42,000	$ 1,046,000	$ 325,000
Held-to-maturity Securities		101,356,000	0	0
Mortgage banking income		872,000	922,000	456,000
Other securities		217,000	304,000	382,000
Residential real estate held in other real estate owned		42,000	57,000
Foreclosure proceedings in process		308,000	426,000
Mortgage servicing rights		126,000	144,000
Mortgage servicing rights, amortization		18,000	30,000	24,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures		277,000	321,000
Low Income Housing Tax Credit		$ 46,000	$ 46,000	$ 46,000
Federal tax rate		34.00%	34.00%	34.00%
Reduction in write-down of deferred tax asset		$ 1,169,000
Core Deposit Intangible, Amortization Period		10 years
Goodwill, Impairment Loss		$ 0	$ 0	$ 0
Class of warrant or right, outstanding		0	0	0
Scenario Forecast [Member]
Federal tax rate	21.00%
Federal Home Loan Bank of Pittsburgh [Member]
Other securities		$ 114,000	$ 135,000
Restricted investments		4,384,000	2,443,000
Reserve for Off-balance Sheet Activities [Member]
Valuation Allowances and Reserves, Balance		$ 105,000	$ 120,000
Commercial [Member]
Loan Terms		1 year
Loan To Value Ratio		80.00%
Maximum [Member]
Maturity of interest bearing time deposits with other financial institutions		1 year
Non-residential consumer loans charged off on contractual basis in event of bankruptcy, in period		120 days
Maximum [Member] | Building Assets [Member]
Property, Plant and Equipment, Useful Life		50 years
Maximum [Member] | Furniture, Fixtures, and Equipment [Member]
Property, Plant and Equipment, Useful Life		10 years
Maximum [Member] | Land Improvements [Member]
Property, Plant and Equipment, Useful Life		20 years
Maximum [Member] | Leasehold Improvements [Member]
Property, Plant and Equipment, Useful Life		30 years
Maximum [Member] | Home equity lines of credit [Member]
Loan Terms		20 years
Loan To Value Ratio		85.00%
Maximum [Member] | Home Equity Lines Of Credit [Member]
Loan Terms		5 years
Maximum [Member] | Residential Portfolio [Member]
Loan Terms		30 years
Loan To Value Ratio		100.00%
Loan To Value Ratio, Exposure After Private Mortgage Insurance		85.00%
Minimum [Member] | Building Assets [Member]
Property, Plant and Equipment, Useful Life		5 years
Minimum [Member] | Furniture, Fixtures, and Equipment [Member]
Property, Plant and Equipment, Useful Life		3 years
Minimum [Member] | Land Improvements [Member]
Property, Plant and Equipment, Useful Life		10 years
Minimum [Member] | Leasehold Improvements [Member]
Property, Plant and Equipment, Useful Life		10 years

Summary of Significant Accoun56

Summary of Significant Accounting Policies (Basic Earnings (Loss) Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income									$ 7,089	$ 7,804	$ 6,528
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS	$ 501	$ 2,249	$ 2,345	$ 1,994	$ 2,076	$ 1,901	$ 2,022	$ 1,805	$ 7,089	$ 7,804	$ 6,038
Weighted average common shares outstanding									4,236,616	4,229,284	4,106,548
Basic earnings per common share	$ 0.12	$ 0.53	$ 0.55	$ 0.47	$ 0.49	$ 0.45	$ 0.48	$ 0.43	$ 1.67	$ 1.85	$ 1.47
Series B Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dividends on preferred stock											$ 373
Redemption premium on preferred stock											100
Series C Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dividends on preferred stock											$ 17

Mergers and Acquisitions (Narra

Mergers and Acquisitions (Narrative) (Details) - USD ($)	Jan. 16, 2018	Jan. 08, 2018	Mar. 01, 2015	Feb. 27, 2015	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill						$ 3,918,000	$ 3,918,000
Net Income (Loss) Attributable to Parent						$ 7,089,000	$ 7,804,000	$ 6,528,000
Series C Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred Stock, Shares Issued			1,750
Preferred Stock, Liquidation Preference Per Share			$ 1,000
Scottdale Bank and Trust Company [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Date of acquisition		Jan. 8, 2018
Plan of merger agreement, date		Mar. 29, 2017
Per share price		$ 1,166
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares		1,900,000
Payments to Acquire Businesses, Gross		$ 2,800,000
Business Combination, Consideration Transferred		$ 66,972,000
First Priority Financial Corp. [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Plan of merger agreement, date	Jan. 16, 2018
Shares Of Acquirer Ratio Of Common Stock	34.81%
Phoenix Bancorp Inc. [Member]
Business Acquisition [Line Items]
Ratio of conversion of acquiree's shares to entity's shares			316.70%
Per share price			$ 51.60	$ 15.60
Shares Of Acquirer Ratio Of Common Stock			41.40%
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares			723,851
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable			$ 11,292,000
Payments to Acquire Businesses, Gross			2,949,000	$ 2,949,000
Business Combination, Consideration Transferred			$ 14,241,000
Preferred Stock, Shares Issued			1,750
Goodwill			$ 2,902,000
Business Combination, Acquired Receivables, Fair Value			112,816,000
Pro Forma Earnings								5,811,000
Revenues					$ 4,244,000
Net Income (Loss) Attributable to Parent					$ 747,000
Phoenix Bancorp Inc. [Member] | Acquisition-related Costs [Member]
Business Acquisition [Line Items]
Pro Forma Earnings								$ 762,000
Phoenix Bancorp Inc. [Member] | Core Deposits [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired			$ 578,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			10 years
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months			$ 75,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two			65,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three			54,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four			44,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five			33,000
Finite-Lived Intangible Assets, Amortization Expense, after Year Five			$ 37,000
Phoenix Bancorp Inc. [Member] | Series C Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred Stock, Shares Issued			1,750
Preferred Stock, Liquidation Preference Per Share			$ 1,000

Mergers and Acquisitions (Alloc

Mergers and Acquisitions (Allocation of the Purchase Price) (Details) - USD ($)	Mar. 01, 2015	Feb. 27, 2015	Dec. 31, 2017	Dec. 31, 2016
Assets acquired:
Goodwill			$ 3,918,000	$ 3,918,000
Phoenix Bancorp Inc. [Member]
Assets acquired:
Cash and cash equivalents	$ 11,044,000
Investment securities	11,331,000
Loans	110,363,000
Goodwill	2,902,000
Core deposit and other intangibles	578,000
Other assets	7,489,000
Total assets acquired	143,707,000
Liabilities assumed:
Deposits	123,238,000
FHLB borrowings	3,570,000
Other liabilities	908,000
Total liabilities assumed	127,716,000
Equity acquired:
Preferred stock	1,750,000
Total equity acquired and liabilities assumed	129,466,000
Consideration paid	14,241,000
Cash paid	2,949,000	$ 2,949,000
Fair value of common stock issued, including replacement equity awards	$ 11,292,000

Mergers and Acquisitions (Estim

Mergers and Acquisitions (Estimated Fair Value of Assets Acquired) (Details) - USD ($)	Mar. 01, 2015	Dec. 31, 2017	Dec. 31, 2016
Net assets acquired:
Goodwill		$ 3,918,000	$ 3,918,000
Phoenix Bancorp Inc. [Member]
Business Acquisition [Line Items]
Total purchase price	$ 14,241,000
Net assets acquired:
Cash and cash equivalents	11,044,000
Investment securities	11,331,000
Restricted stock	509,000
Loans	110,363,000
Bank owned life insurance	3,673,000
Premises and equipment	1,792,000
Deferred income taxes	503,000
Accrued interest receivable	388,000
Core deposit and other intangibles	578,000
Other assets	624,000
Deposits	(123,238,000)
FHLB borrowings	(3,570,000)
Accrued interest payable	(32,000)
Other liabilities	(876,000)
Preferred stock	(1,750,000)
Total net assets acquired	11,339,000
Goodwill	$ 2,902,000

Mergers and Acquisitions (Fair

Mergers and Acquisitions (Fair Value Adjustments) (Details) - Phoenix Bancorp Inc. [Member]	Mar. 01, 2015USD ($)
Business Acquisition [Line Items]
Gross amortized cost basis at March 1, 2015	$ 112,816,000
Market rate adjustment	270,000
Credit fair value adjustment on pools of homogeneous loans	(1,461,000)
Credit fair value adjustment on impaired loans	(1,262,000)
Fair value of purchased loans	$ 110,363,000

Mergers and Acquisitions (Fai61

Mergers and Acquisitions (Fair Value of Loans Acquired) (Details) - Phoenix Bancorp Inc. [Member] $ in Thousands	Mar. 01, 2015USD ($)
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition	$ 3,548
Contractual cash flows not expected to be collected (nonaccretable discount)	(804)
Expected cash flows at acquisition	2,744
Interest component of expected cash flows (accretable discount)	(458)
Fair value of acquired loans	$ 2,286

Mergers and Acquisitions (Unaud

Mergers and Acquisitions (Unaudited Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Net interest income after loan loss provision	$ 9,387	$ 9,516	$ 9,310	$ 9,050	$ 8,579	$ 8,173	$ 8,148	$ 8,075	$ 37,263	$ 32,975	$ 30,818
Noninterest income	1,331	1,564	1,362	1,436	1,875	1,419	1,398	1,232	5,693	5,924	4,113
Noninterest expense	$ 8,047	$ 7,960	$ 7,558	$ 7,802	$ 7,740	$ 7,165	$ 6,931	$ 6,982	$ 31,367	$ 28,818	26,759
Phoenix Bancorp Inc. [Member]
Business Acquisition [Line Items]
Net interest income after loan loss provision											31,454
Noninterest income											4,152
Noninterest expense											27,817
Net income available to common shareholders											$ 5,811
Net income per common share											$ 1.38

Accumulated Other Comprehensi63

Accumulated Other Comprehensive (Loss) Income (Accumulated Other Comprehensive (Loss) Income, Net of Taxes) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Unrealized (Loss) Gain on Securities	$ (2,159)	$ (2,919)
Defined Benefit Plan Liability	85	66
Accumulated Other Comprehensive (Loss) Income	$ (2,074)	$ (2,853)

Investment Securities (Unrealiz

Investment Securities (Unrealized Gain (Loss) on Investments) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Available-for-sale securities, Amortized Cost	$ 96,198,000	$ 138,048,000
Available-for-sale securities, Unrealized Gains	14,000	142,000
Available-for-sale securities, Unrealized Losses	2,747,000	4,565,000
Available for sale Securities, Fair Value	93,465,000	133,625,000
Held-to-maturity securities, Amortized Cost	101,356,000	0	$ 0
Held-to-maturity securities, Unrealized Gains	41,000
Held-to-maturity securities, Unrealized Losses	914,000
Held-to-maturity securities, Fair Value	100,483,000	0
Available-for-sale securities and Held-to-maturity securities, Amortized Cost	197,554,000
Available-for-sale securities and Held-to-maturity securities, Unrealized Gains	55,000
Available-for-sale securities and Held-to-maturity securities, Unrealized Losses	3,661,000
Available-for-sale securities and Held-to-maturity securities, Fair Value	193,948,000
U.S. Treasury and U.S. government agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Amortized Cost	40,125,000	48,520,000
Available-for-sale securities, Unrealized Gains		34,000
Available-for-sale securities, Unrealized Losses	1,395,000	1,542,000
Available for sale Securities, Fair Value	38,730,000	47,012,000
Held-to-maturity securities, Amortized Cost	10,984,000
Held-to-maturity securities, Unrealized Losses	90,000
Held-to-maturity securities, Fair Value	10,894,000
Mortgage-backed U.S. Government Agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Amortized Cost	26,398,000	26,181,000
Available-for-sale securities, Unrealized Gains	2,000	17,000
Available-for-sale securities, Unrealized Losses	569,000	579,000
Available for sale Securities, Fair Value	25,831,000	25,619,000
Held-to-maturity securities, Amortized Cost	53,472,000
Held-to-maturity securities, Unrealized Losses	523,000
Held-to-maturity securities, Fair Value	52,949,000
State and political subdivision obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Amortized Cost	27,775,000	61,079,000
Available-for-sale securities, Unrealized Gains	7,000	91,000
Available-for-sale securities, Unrealized Losses	739,000	2,332,000
Available for sale Securities, Fair Value	27,043,000	58,838,000
Held-to-maturity securities, Amortized Cost	36,900,000
Held-to-maturity securities, Unrealized Gains	41,000
Held-to-maturity securities, Unrealized Losses	301,000
Held-to-maturity securities, Fair Value	36,640,000
Corporate debt securities [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Amortized Cost	1,000,000	1,000,000
Available-for-sale securities, Unrealized Gains	5,000
Available for sale Securities, Fair Value	1,005,000	1,000,000
Equity Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Amortized Cost	900,000	1,268,000
Available-for-sale securities, Unrealized Losses	44,000	112,000
Available for sale Securities, Fair Value	$ 856,000	$ 1,156,000

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Securities Financing Transactions Disclosures [Abstract]
Held-to-maturity Securities	$ 101,356,000	$ 0	$ 0
Available-for-sale Securities Pledged as Collateral	$ 141,465,000	$ 131,469,000

Investment Securities (Schedule

Investment Securities (Schedule of Fair Value and Unrealized Loss on Investments in a Continuous Unrealized Loss Position) (Details) $ in Thousands	Dec. 31, 2017USD ($)security	Dec. 31, 2016USD ($)security
Schedule of Investments [Line Items]
Available-for-sale securities, Less than 12 Months: Number of Securities | security	18	149
Available-for-sale securities, Less than 12 Months: Fair Value	$ 16,419	$ 118,601
Available-for-sale securities, Less than 12 Months: Unrealized Losses	$ 361	$ 4,453
Available-for-sale securities, 12 Months or More: Number of Securities | security	74	2
Available-for-sale securities, 12 Months or More: Fair Value	$ 73,816	$ 1,056
Available-for-sale securities, 12 Months or More: Unrealized Losses	$ 2,386	$ 112
Available-for-sale securities, Total: Number of Securities | security	92	151
Available-for-sale securities, Total: Fair Value	$ 90,235	$ 119,657
Available-for-sale securities, Total: Unrealized Losses	$ 2,747	$ 4,565
Held-to-maturity securities, Less than 12 Months: Number of Securities | security	0
Held-to-maturity securities, 12 Months or More: Number of Securities | security	116
Held-to-maturity securities, 12 Months or More: Fair Value	$ 93,819
Held-to-maturity securities, 12 Months or More: Unrealized Losses	$ 914
Held-to-maturity securities, Total: Number of Securities | security	116
Held-to-maturity securities, Total: Fair Value	$ 93,819
Held-to-maturity securities, Total: Unrealized Losses	$ 914
Available-for-sale securities and Held-to-maturity securities, Less than 12 Months: Number of Securities | security	18
Available-for-sale securities and Held-to-maturity securities, Less than 12 Months: Fair Value	$ 16,419
Available-for-sale securities and Held-to-maturity securities, Less than 12 Months: Unrealized Losses	$ 361
Available-for-sale securities and Held-to-maturity securities,, 12 Months or More: Number of Securities | security	190
Available-for-sale securities and Held-to-maturity securities, 12 Months or More: Fair Value	$ 167,635
Available-for-sale securities and Held-to-maturity securities, 12 Months or More: Unrealized Losses	$ 3,300
Available-for-sale securities and Held-to-maturity securities, Total: Number of Securities | security	208
Available-for-sale securities and Held-to-maturity securities, Total: Fair Value	$ 184,054
Available-for-sale securities and Held-to-maturity securities, Total: Unrealized Losses	$ 3,661
U.S. Treasury and U.S. government agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Less than 12 Months: Number of Securities | security	3	23
Available-for-sale securities, Less than 12 Months: Fair Value	$ 5,008	$ 43,698
Available-for-sale securities, Less than 12 Months: Unrealized Losses	$ 184	$ 1,542
Available-for-sale securities, 12 Months or More: Number of Securities | security	18	0
Available-for-sale securities, 12 Months or More: Fair Value	$ 33,722
Available-for-sale securities, 12 Months or More: Unrealized Losses	$ 1,211
Available-for-sale securities, Total: Number of Securities | security	21	23
Available-for-sale securities, Total: Fair Value	$ 38,730	$ 43,698
Available-for-sale securities, Total: Unrealized Losses	$ 1,395	$ 1,542
Held-to-maturity securities, Less than 12 Months: Number of Securities | security	0
Held-to-maturity securities, 12 Months or More: Number of Securities | security	4
Held-to-maturity securities, 12 Months or More: Fair Value	$ 10,894
Held-to-maturity securities, 12 Months or More: Unrealized Losses	$ 90
Held-to-maturity securities, Total: Number of Securities | security	4
Held-to-maturity securities, Total: Fair Value	$ 10,894
Held-to-maturity securities, Total: Unrealized Losses	$ 90
Mortgage-backed U.S. Government Agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Less than 12 Months: Number of Securities | security	4	18
Available-for-sale securities, Less than 12 Months: Fair Value	$ 5,267	$ 24,321
Available-for-sale securities, Less than 12 Months: Unrealized Losses	$ 75	$ 579
Available-for-sale securities, 12 Months or More: Number of Securities | security	15	0
Available-for-sale securities, 12 Months or More: Fair Value	$ 20,497
Available-for-sale securities, 12 Months or More: Unrealized Losses	$ 494
Available-for-sale securities, Total: Number of Securities | security	19	18
Available-for-sale securities, Total: Fair Value	$ 25,764	$ 24,321
Available-for-sale securities, Total: Unrealized Losses	$ 569	$ 579
Held-to-maturity securities, Less than 12 Months: Number of Securities | security	0
Held-to-maturity securities, 12 Months or More: Number of Securities | security	35
Held-to-maturity securities, 12 Months or More: Fair Value	$ 52,949
Held-to-maturity securities, 12 Months or More: Unrealized Losses	$ 523
Held-to-maturity securities, Total: Number of Securities | security	35
Held-to-maturity securities, Total: Fair Value	$ 52,949
Held-to-maturity securities, Total: Unrealized Losses	$ 523
State and political subdivision obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Less than 12 Months: Number of Securities | security	11	108
Available-for-sale securities, Less than 12 Months: Fair Value	$ 6,144	$ 50,582
Available-for-sale securities, Less than 12 Months: Unrealized Losses	$ 102	$ 2,332
Available-for-sale securities, 12 Months or More: Number of Securities | security	40	0
Available-for-sale securities, 12 Months or More: Fair Value	$ 19,091
Available-for-sale securities, 12 Months or More: Unrealized Losses	$ 637
Available-for-sale securities, Total: Number of Securities | security	51	108
Available-for-sale securities, Total: Fair Value	$ 25,235	$ 50,582
Available-for-sale securities, Total: Unrealized Losses	$ 739	$ 2,332
Held-to-maturity securities, Less than 12 Months: Number of Securities | security	0
Held-to-maturity securities, 12 Months or More: Number of Securities | security	77
Held-to-maturity securities, 12 Months or More: Fair Value	$ 29,976
Held-to-maturity securities, 12 Months or More: Unrealized Losses	$ 301
Held-to-maturity securities, Total: Number of Securities | security	77
Held-to-maturity securities, Total: Fair Value	$ 29,976
Held-to-maturity securities, Total: Unrealized Losses	$ 301
Corporate debt securities [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Less than 12 Months: Number of Securities | security	0	0
Available-for-sale securities, 12 Months or More: Number of Securities | security	0	0
Available-for-sale securities, Total: Number of Securities | security	0	0
Held-to-maturity securities, Less than 12 Months: Number of Securities | security	0
Held-to-maturity securities, 12 Months or More: Number of Securities | security	0
Held-to-maturity securities, Total: Number of Securities | security	0
Equity Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, Less than 12 Months: Number of Securities | security	0	0
Available-for-sale securities, 12 Months or More: Number of Securities | security	1	2
Available-for-sale securities, 12 Months or More: Fair Value	$ 506	$ 1,056
Available-for-sale securities, 12 Months or More: Unrealized Losses	$ 44	$ 112
Available-for-sale securities, Total: Number of Securities | security	1	2
Available-for-sale securities, Total: Fair Value	$ 506	$ 1,056
Available-for-sale securities, Total: Unrealized Losses	$ 44	$ 112
Held-to-maturity securities, Less than 12 Months: Number of Securities | security	0
Held-to-maturity securities, 12 Months or More: Number of Securities | security	0
Held-to-maturity securities, Total: Number of Securities | security	0

Investment Securities (Schedu67

Investment Securities (Schedule of Gross Realized Gains (Losses) on Sales of Available-For-Sale Securities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Securities Financing Transactions Disclosures [Abstract]
Realized gains	$ 246	$ 1,927	$ 325
Realized losses	(204)	(881)
Net gains	$ 42	$ 1,046	$ 325

Investment Securities (Investme

Investment Securities (Investments Classified by Contractual Maturity Date) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Available for sale Securities, Amortized Cost, Due in 1 year or less	$ 100,000
Available for sale Securities, Amortized Cost, Due after 1 year but within 5 years	12,072,000
Available for sale Securities, Amortized Cost, Due after 5 years but within 10 years	46,307,000
Available for sale Securities, Amortized Cost, Due after 10 years	10,771,000
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Total	69,250,000
Equity Securities, Amortized Cost	550,000
Available-for-sale securities, Amortized Cost	96,198,000	$ 138,048,000
Available for sale Securities, Fair Value, Due in 1 year or less	100,000
Available for sale Securities, Fair Value, Due after 1 year but within 5 years	11,825,000
Available for sale Securities, Fair Value, Due after 5 years but within 10 years	44,779,000
Available for sale Securities, Fair Value, Due after 10 years	10,424,000
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Fair Value, Total	67,128,000
Equity Securities, Fair Value	506,000
Available for sale Securities, Fair Value	93,465,000	133,625,000
Held-to-maturity, Due in 1 year or less, Amortized Cost	2,001,000
Held-to-maturity, Due after 1 year through 5 years, Amortized Cost	9,431,000
Held-to-maturity, Due after 5 years through 10 years, Amortized Cost	35,941,000
Held-to-maturity, Due after 10 years, Amortized Cost	511,000
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis	47,884,000
Held-to-maturity securities, Amortized Cost	101,356,000	0	$ 0
Held-to-maturity, Due in 1 year or less, Fair Value	1,989,000
Held-to-maturity, Due after 1 year through 5, Fair Value	9,357,000
Held-to-maturity, Due after 5 years through 10 years, Fair Value	35,679,000
Held-to-maturity, Due after 10 years, Fair Value	509,000
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value	47,534,000
Held-to-maturity, Fair Value	100,483,000	$ 0
Mortgage-backed securities [Member]
Schedule of Investments [Line Items]
Available for sale Securities without a Single Maturity Date, Amortized Cost	26,398,000
Available for sale securities without a Single Maturity Date, Fair Value	25,831,000
Held-to-maturity without Single Maturity Date, Amortized Cost	53,472,000
Held-to-maturity without Single Maturity Date, Fair Value	$ 52,949,000

Loans and Allowance for Loan 69

Loans and Allowance for Loan and Lease Losses (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)Loan	Dec. 31, 2016USD ($)Loan	Dec. 31, 2015USD ($)	Dec. 31, 2014Loan	Dec. 31, 2013Loan	Dec. 31, 2009Loan	Dec. 31, 2008Loan
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable Deferred Fees And Costs	$ 464,000,000	$ 196,000,000
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	780,000	778,000	$ 798,000
Loans and Leases Receivable, Impaired, Commitment to Lend		0
Financing Receivable, Modifications, Recorded Investment	9,571,000	3,515,000
Charge-offs associated with troubled debt restructured loans	$ 66,000	$ 0
Number of troubled debt restructured loans | Loan	0	0
Loans to certain executive officers, directors, and their related interests	$ 15,163,000,000	$ 17,634,000,000
Loans to certain executive officers, directors, and their related interests, new loans and advances	2,178,000,000
Loans to certain executive officers, directors, and their related interests, Repayments	4,649,000,000
Accruing [Member] | Four Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	544,000
Accruing [Member] | Five Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		877,000
Nonaccruing [Member] | Fifteen Loans With Seven Relationships [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	9,027,000
Nonaccruing [Member] | Two Large Relationships [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	7,284,000	2,170,000
Nonaccruing [Member] | Ten Loans With Four Relationships [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2,638,000
Residential Mortgage [Member] | Residential Portfolio [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	544,000	639,000
Residential Mortgage [Member] | Residential Portfolio [Member] | Accruing [Member] | Three Unrelated Borrowers [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 540,000
Residential Mortgage [Member] | Residential Portfolio [Member] | Accruing [Member] | Four Unrelated Borrowers [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		$ 571,000
Under Forbearance Agreement 2017 Period [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of forbearance agreements negotiated | Loan	10			1	1	6	1
Under Forbearance Agreement 2016 Period [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of forbearance agreements negotiated | Loan		3		1	2	8	1
Home Equity Loan [Member] | Accruing [Member] | Other Borrower [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 4,000
Commercial Real Estate [Member] | Commercial Portfolio [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 4,593,000	$ 2,871,000
Commercial Real Estate [Member] | Commercial Portfolio [Member] | Accruing [Member] | Other Borrower [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		$ 306,000

Loans and Allowance for Loan 70

Loans and Allowance for Loan and Lease Losses (Classes Of The Loan Portfolio Summarized By The Aggregate Risk Rating) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	$ 910,404	$ 813,924	$ 736,513
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	41,893	37,608	33,411
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	892,622	799,937
Pass [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	41,479	37,242
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	2,332	3,071
Special Mention [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	105	142
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	15,450	10,916
Substandard [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	309	224
Commercial Portfolio [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	188,033	172,518	160,261
Commercial Portfolio [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	515,012	446,524	369,464
Commercial Portfolio [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	62,336	54,376	68,068
Commercial Portfolio [Member] | Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	229	425	727
Commercial Portfolio [Member] | Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	182,168	170,780
Commercial Portfolio [Member] | Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	505,397	437,592
Commercial Portfolio [Member] | Pass [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	61,667	52,888
Commercial Portfolio [Member] | Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	453	937
Commercial Portfolio [Member] | Special Mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,435	1,683
Commercial Portfolio [Member] | Special Mention [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	182	202
Commercial Portfolio [Member] | Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	5,412	801
Commercial Portfolio [Member] | Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	8,180	7,249
Commercial Portfolio [Member] | Substandard [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	487	1,286
Finance Leases Portfolio [Member] | Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	229	425
Finance Leases Portfolio [Member] | Pass [Member] | Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	229	425
Residential Portfolio [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	99,033	99,457	100,665
Residential Portfolio [Member] | Pass [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	97,814	97,994
Residential Portfolio [Member] | Special Mention [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	157	107
Residential Portfolio [Member] | Substandard [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,062	1,356
Consumer Portfolio [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	3,868	3,016	$ 3,917
Consumer Portfolio [Member] | Pass [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	$ 3,868	$ 3,016

Loans and Allowance for Loan 71

Loans and Allowance for Loan and Lease Losses (Impaired Loans by Loan Portfolio Class) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Recorded Investment	$ 260	$ 111
Impaired Loans with No Allowance: Unpaid Principal Balance	295	129
Impaired Loans with Allowance: Recorded Investment		29
Impaired Loans with Allowance: Unpaid Principal Balance		49
Impaired Loans with Allowance: Related Allowance		1
Impaired Loans: Total Recorded Investment	260	140
Impaired Loans: Total Unpaid Principal Balance	295	178
Commercial Portfolio [Member] | Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Recorded Investment		4
Impaired Loans with No Allowance: Unpaid Principal Balance	13	9
Impaired Loans with Allowance: Recorded Investment	4,434	56
Impaired Loans with Allowance: Unpaid Principal Balance	4,460	62
Impaired Loans with Allowance: Related Allowance	136	6
Impaired Loans: Total Recorded Investment	4,434	60
Impaired Loans: Total Unpaid Principal Balance	4,473	71
Commercial Portfolio [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Recorded Investment	3,424	726
Impaired Loans with No Allowance: Unpaid Principal Balance	4,056	1,792
Impaired Loans with Allowance: Recorded Investment	1,423	2,520
Impaired Loans with Allowance: Unpaid Principal Balance	1,589	2,646
Impaired Loans with Allowance: Related Allowance	293	711
Impaired Loans: Total Recorded Investment	5,402	4,088
Impaired Loans: Total Unpaid Principal Balance	6,200	5,280
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Recorded Investment	555	842
Impaired Loans with No Allowance: Unpaid Principal Balance	555	842
Commercial Portfolio [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Recorded Investment		618
Impaired Loans with No Allowance: Unpaid Principal Balance		618
Impaired Loans with Allowance: Recorded Investment	487	242
Impaired Loans with Allowance: Unpaid Principal Balance	492	242
Impaired Loans with Allowance: Related Allowance	100	72
Impaired Loans: Total Recorded Investment	487	860
Impaired Loans: Total Unpaid Principal Balance	492	860
Residential Portfolio [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Recorded Investment	760	848
Impaired Loans with No Allowance: Unpaid Principal Balance	877	882
Impaired Loans with Allowance: Recorded Investment		68
Impaired Loans with Allowance: Unpaid Principal Balance		68
Impaired Loans with Allowance: Related Allowance		68
Impaired Loans: Total Recorded Investment	1,066	1,305
Impaired Loans: Total Unpaid Principal Balance	1,183	1,339
Residential Portfolio [Member] | Residential Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Recorded Investment	306	389
Impaired Loans with No Allowance: Unpaid Principal Balance	$ 306	$ 389

Loans and Allowance for Loan 72

Loans and Allowance for Loan and Lease Losses (Average Recorded Investment Of Impaired Loans And Related Interest Income By Loan Portfolio Class) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Average Recorded Investment	$ 218	$ 75	$ 107
Impaired Loans with No Allowance: Interest Income Recognized	6
Impaired Loans with Allowance: Average Recorded Investment		32
Impaired Financing Receivable, Average Recorded Investment, Total	218	107	107
Impaired Financing Receivable, Interest Income Recognized, Total	6		3
Home Equity [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Interest Income Recognized			3
Commercial Portfolio [Member] | Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Average Recorded Investment	15	9	19
Impaired Loans with Allowance: Average Recorded Investment	1,779	59	123
Impaired Financing Receivable, Average Recorded Investment, Total	1,794	68	142
Impaired Financing Receivable, Interest Income Recognized, Total			205
Commercial Portfolio [Member] | Commercial and Industrial [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Interest Income Recognized			205
Commercial Portfolio [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Average Recorded Investment	1,915	820	1,051
Impaired Loans with No Allowance: Interest Income Recognized	279		14
Impaired Loans with Allowance: Average Recorded Investment	1,446	2,177	1,721
Impaired Financing Receivable, Average Recorded Investment, Total	4,012	3,807	3,698
Impaired Financing Receivable, Interest Income Recognized, Total	389	164	364
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Average Recorded Investment	651	810	926
Impaired Loans with No Allowance: Interest Income Recognized	110	164	350
Commercial Portfolio [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Average Recorded Investment	164	124
Impaired Loans with Allowance: Average Recorded Investment	488	48
Impaired Financing Receivable, Average Recorded Investment, Total	652	172
Residential Portfolio [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Average Recorded Investment	890	821	816
Impaired Loans with No Allowance: Interest Income Recognized	18	21	8
Impaired Loans with Allowance: Average Recorded Investment		14	25
Impaired Financing Receivable, Average Recorded Investment, Total	1,222	1,213	1,241
Impaired Financing Receivable, Interest Income Recognized, Total	18	25	8
Residential Portfolio [Member] | Residential Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans with No Allowance: Average Recorded Investment	$ 332	378	$ 400
Impaired Loans with No Allowance: Interest Income Recognized		$ 4

Loans and Allowance for Loan 73

Loans and Allowance for Loan and Lease Losses (Nonaccrual Loans By Classes Of The Loan Portfolio) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 10,575	$ 4,658
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	260	140
Commercial Portfolio [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	4,434	4
Commercial Portfolio [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	4,902	2,939
Commercial Portfolio [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	487	860
Residential Portfolio [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 492	$ 715

Loans and Allowance for Loan 74

Loans and Allowance for Loan and Lease Losses (Loan Portfolio Summarized By The Past Due Status) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 10,749	$ 3,524
Financing Receivable, Recorded Investment, Current	899,655	810,400
Total Loans	910,404	813,924	$ 736,513
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		59
Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	861	1,231	1,331
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,306	1,220
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	612	553
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,831	1,751
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	402	171
Financing Receivable, Recorded Investment, Current	41,491	37,437
Total Loans	41,893	37,608	33,411
Home Equity [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	54	33
Home Equity [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	98	13
Home Equity [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	250	125
Commercial Portfolio [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,455	180
Financing Receivable, Recorded Investment, Current	183,578	172,338
Total Loans	188,033	172,518	160,261
Commercial Portfolio [Member] | Commercial and Industrial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,439	164
Commercial Portfolio [Member] | Commercial and Industrial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	16	12
Commercial Portfolio [Member] | Commercial and Industrial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due		4
Commercial Portfolio [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	515,012	446,524	369,464
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Excluded Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,669	1,479
Financing Receivable, Recorded Investment, Current	510,788	444,203
Total Loans	514,457	445,682
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	555	59
Financing Receivable, Recorded Investment, Current		783
Total Loans	555	842	931
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		59
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Excluded Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due		475
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	500
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Excluded Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,669	1,004
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	55	59
Commercial Portfolio [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	487	488
Financing Receivable, Recorded Investment, Current	61,849	53,888
Total Loans	62,336	54,376	68,068
Commercial Portfolio [Member] | Commercial Real Estate - Construction [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due		404
Commercial Portfolio [Member] | Commercial Real Estate - Construction [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	487	84
Commercial Portfolio [Member] | Lease Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Current	229	425
Total Loans	229	425	727
Residential Portfolio [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	99,033	99,457	100,665
Residential Portfolio [Member] | Residential Mortgage [Member] | Excluded Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	954	909
Financing Receivable, Recorded Investment, Current	97,773	98,159
Total Loans	98,727	99,068
Residential Portfolio [Member] | Residential Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	224	238
Financing Receivable, Recorded Investment, Current	82	151
Total Loans	306	389	400
Residential Portfolio [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Mortgage [Member] | Excluded Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	310	548
Residential Portfolio [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Mortgage [Member] | Excluded Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	467	124
Residential Portfolio [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	31
Residential Portfolio [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Mortgage [Member] | Excluded Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	177	237
Residential Portfolio [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	193	238
Consumer Portfolio [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3
Financing Receivable, Recorded Investment, Current	3,865	3,016
Total Loans	3,868	$ 3,016	$ 3,917
Consumer Portfolio [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 3

Loans and Allowance for Loan 75

Loans and Allowance for Loan and Lease Losses (Allowance For Loan Losses And Recorded Investment In Financing Receivables) (Details) - USD ($) $ in Thousands	3 Months Ended							12 Months Ended
	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			$ 7,183				$ 6,168	$ 7,183	$ 6,168	$ 6,716
Charge-offs								(497)	(1,107)	(1,784)
Recoveries								595	252	171
Provisions	$ 100	$ 100	125	$ 550	$ 585	$ 395	340	325	1,870	1,065
Allowance for Loan Losses, Ending Balance	7,606			7,183				7,606	7,183	6,168
Allowance for loan losses: Ending balance: individually evaluated for impairment	529			858				529	858	503
Allowance for loan losses: Ending balance: collectively evaluated for impairment	7,077			6,325				7,077	6,325	5,665
Loans receivables, Ending Balance	910,404			813,924				910,404	813,924	736,513
Loans receivables: Ending balance: individually evaluated for impairment	10,788			5,222				10,788	5,222	4,573
Loans Receivable: Ending balance: collectively evaluated for impairment	898,755			807,471				898,755	807,471	730,609
Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivables, Ending Balance	861			1,231				861	1,231	1,331
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			379				317	379	317	653
Charge-offs								(20)	(25)	(36)
Recoveries								5		29
Provisions								59	87	(329)
Allowance for Loan Losses, Ending Balance	423			379				423	379	317
Allowance for loan losses: Ending balance: individually evaluated for impairment				1					1
Allowance for loan losses: Ending balance: collectively evaluated for impairment	423			378				423	378	317
Loans receivables, Ending Balance	41,893			37,608				41,893	37,608	33,411
Loans receivables: Ending balance: individually evaluated for impairment	260			140				260	140	115
Loans Receivable: Ending balance: collectively evaluated for impairment	41,633			37,468				41,633	37,468	33,296
Commercial Portfolio [Member] | Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			1,580				1,393	1,580	1,393	1,393
Charge-offs								(25)	(820)	(130)
Recoveries								26	4	12
Provisions								214	1,003	118
Allowance for Loan Losses, Ending Balance	1,795			1,580				1,795	1,580	1,393
Allowance for loan losses: Ending balance: individually evaluated for impairment	136			6				136	6	51
Allowance for loan losses: Ending balance: collectively evaluated for impairment	1,659			1,574				1,659	1,574	1,342
Loans receivables, Ending Balance	188,033			172,518				188,033	172,518	160,261
Loans receivables: Ending balance: individually evaluated for impairment	4,434			60				4,434	60	127
Loans Receivable: Ending balance: collectively evaluated for impairment	183,599			172,458				183,599	172,458	160,134
Commercial Portfolio [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			4,323				3,552	4,323	3,552	3,925
Charge-offs								(322)	(216)	(1,569)
Recoveries								553	211	75
Provisions								(119)	776	1,121
Allowance for Loan Losses, Ending Balance	4,435			4,323				4,435	4,323	3,552
Allowance for loan losses: Ending balance: individually evaluated for impairment	293			711				293	711	429
Allowance for loan losses: Ending balance: collectively evaluated for impairment	4,142			3,612				4,142	3,612	3,123
Loans receivables, Ending Balance	515,012			446,524				515,012	446,524	369,464
Loans receivables: Ending balance: individually evaluated for impairment	4,847			3,246				4,847	3,246	2,970
Loans Receivable: Ending balance: collectively evaluated for impairment	509,610			442,436				509,610	442,436	365,563
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivables, Ending Balance	555			842				555	842	931
Commercial Portfolio [Member] | Commercial Real Estate - Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			144				153	144	153	33
Provisions								34	(9)	120
Allowance for Loan Losses, Ending Balance	178			144				178	144	153
Allowance for loan losses: Ending balance: individually evaluated for impairment	100			72				100	72
Allowance for loan losses: Ending balance: collectively evaluated for impairment	78			72				78	72	153
Loans receivables, Ending Balance	62,336			54,376				62,336	54,376	68,068
Loans receivables: Ending balance: individually evaluated for impairment	487			860				487	860
Loans Receivable: Ending balance: collectively evaluated for impairment	61,849			53,516				61,849	53,516	68,068
Commercial Portfolio [Member] | Lease Financing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			1				1	1	1	2
Provisions								(1)		(1)
Allowance for Loan Losses, Ending Balance				1					1	1
Allowance for loan losses: Ending balance: collectively evaluated for impairment				1					1	1
Loans receivables, Ending Balance	229			425				229	425	727
Loans Receivable: Ending balance: collectively evaluated for impairment	229			425				229	425	727
Residential Portfolio [Member] | Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			541				534	541	534	450
Charge-offs								(102)	(4)	(35)
Recoveries								4	26	44
Provisions								(15)	(15)	75
Allowance for Loan Losses, Ending Balance	428			541				428	541	534
Allowance for loan losses: Ending balance: individually evaluated for impairment				68					68	23
Allowance for loan losses: Ending balance: collectively evaluated for impairment	428			473				428	473	511
Loans receivables, Ending Balance	99,033			99,457				99,033	99,457	100,665
Loans receivables: Ending balance: individually evaluated for impairment	760			916				760	916	1,361
Loans Receivable: Ending balance: collectively evaluated for impairment	97,967			98,152				97,967	98,152	98,904
Residential Portfolio [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivables, Ending Balance	306			389				306	389	400
Consumer Portfolio [Member] | Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			3				12	3	12	35
Charge-offs								(28)	(42)	(14)
Recoveries								7	11	11
Provisions								21	22	(20)
Allowance for Loan Losses, Ending Balance	3			3				3	3	12
Allowance for loan losses: Ending balance: collectively evaluated for impairment	3			3				3	3	12
Loans receivables, Ending Balance	3,868			3,016				3,868	3,016	3,917
Loans Receivable: Ending balance: collectively evaluated for impairment	3,868			3,016				3,868	3,016	3,917
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance			$ 212				$ 206	212	206	225
Provisions								132	6	(19)
Allowance for Loan Losses, Ending Balance	344			212				344	212	206
Allowance for loan losses: Ending balance: collectively evaluated for impairment	$ 344			$ 212				$ 344	$ 212	$ 206

Loans and Allowance for Loan 76

Loans and Allowance for Loan and Lease Losses (Troubled Debt Restructurings) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)Loancontract	Dec. 31, 2016USD ($)Loan
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 10,536,000	$ 5,368,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	10,730,000	4,823,000
Financing Receivable, Modifications, Recorded Investment	$ 9,571,000	$ 3,515,000
Financing Receivable, Modifications, Number of Contracts | Loan	0	0
Entity Loan Modification Program
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 7,322,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	7,610,000
Financing Receivable, Modifications, Recorded Investment	$ 7,574,000
Financing Receivable, Modifications, Number of Contracts | contract	10
Commercial Portfolio [Member] | Commercial and Industrial [Member] | Entity Loan Modification Program
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 4,110,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	4,460,000
Financing Receivable, Modifications, Recorded Investment	$ 4,434,000
Financing Receivable, Modifications, Number of Contracts | contract	1
Commercial Portfolio [Member] | Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 4,110,000	$ 40,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	4,460,000	35,000
Financing Receivable, Modifications, Recorded Investment	4,434,000	5,000
Commercial Portfolio [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	5,735,000	4,569,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	5,581,000	4,031,000
Financing Receivable, Modifications, Recorded Investment	4,593,000	2,871,000
Commercial Portfolio [Member] | Commercial Real Estate [Member] | Entity Loan Modification Program
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	3,212,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	3,150,000
Financing Receivable, Modifications, Recorded Investment	$ 3,140,000
Financing Receivable, Modifications, Number of Contracts | contract	9
Residential Portfolio [Member] | Residential Mortgage [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 691,000	759,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	689,000	757,000
Financing Receivable, Modifications, Recorded Investment	$ 544,000	$ 639,000

Loans and Allowance for Loan 77

Loans and Allowance for Loan and Lease Losses (Schedule of Accretion of Purchased Impaired Loan) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Accounts Notes Loans And Financing Receivable Gross Allowance And Net [Abstract]
Accretable yield, beginning balance	$ 67
Accretable yield amortized to interest income	(23)
Reclassification from nonaccretable difference	23	[1]
Accretable yield, ending balance	$ 67
[1]	Reclassification from non-accretable difference represents an increase to the estimated cash flows to be collected on the underlying portfolio.

Bank Premises and Equipment (Pr

Bank Premises and Equipment (Premises and Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total cost	$ 26,051	$ 21,537
Less accumulated depreciation	(9,883)	(10,463)
Net book value of bank premises and equipment	16,168	11,074
Assets held for sale		1,894
Total bank premises and equipment	16,168	12,968
Land [Member]
Property, Plant and Equipment [Line Items]
Total cost	3,564	2,315
Buildings [Member]
Property, Plant and Equipment [Line Items]
Total cost	8,632	9,517
Furniture, Fixtures, and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	8,262	8,184
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total cost	1,126	1,432
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 4,467	$ 89

Bank Premises and Equipment (Na

Bank Premises and Equipment (Narrative) (Details)	Jan. 20, 2017USD ($)Property	Dec. 31, 2017USD ($)LeaseAdministrative_Office	Dec. 31, 2016USD ($)Lease	Dec. 31, 2015USD ($)
Property, Plant and Equipment [Line Items]
Bank premises and equipment held for sale		$ 0	$ 1,894,000
Asset held for sale, description		As of December 31, 2016, assets held-for-sale consisted of three full service retail banking properties. These properties were transferred from land and buildings to assets held for sale during 2016 due to Mid Penn’s intent to sell them during January 2017.
Number of properties sale | Property	3
Proceeds from sale of three properties	$ 2,240,000	$ 2,201,000
Gain from sale of three properties	$ 346,000	(14,000)	(142,000)
Depreciation		$ 1,464,000	$ 1,658,000	$ 1,485,000
Lease expiration date		Dec. 31, 2035
2,018		$ 1,171,000
2,019		975,000
2,020		790,000
2,021		617,000
2,022		564,000
thereafter		$ 5,113,000
Harrisburg, PA [Member] | Commercial Building and Adjacent Lots [Member]
Property, Plant and Equipment [Line Items]
Number of administrative offices previously leased, replaced | Administrative_Office		2
Minimum [Member]
Property, Plant and Equipment [Line Items]
Length of lease	15 years
Sublease to Unrelated Party [Member]
Property, Plant and Equipment [Line Items]
Lease expiration date			Mar. 31, 2021
Number of operating lease with related parties | Lease			2
Operating Leases Related Party [Member]
Property, Plant and Equipment [Line Items]
Number of operating lease with related parties | Lease		4
Operating leases, rent expense, net		$ 352,000	$ 348,000	$ 279,000
2,018		328,000
2,019		304,000
2,020		305,000
2,021		213,000
2,022		182,000
thereafter		$ 1,937,000
Second Sublease Agreement [Member] | Sublease to Unrelated Party [Member]
Property, Plant and Equipment [Line Items]
Sale and lease back of properties, description		Two of the properties are being leased back by Mid Penn for a period of at least 15 years, and the respective gains on the sales of those properties will be recognized over the life of the leases.
Lease agreement start date			Jul. 1, 2016
First Sublease Agreement [Member] | Sublease to Unrelated Party [Member]
Property, Plant and Equipment [Line Items]
Lease agreement start date			Apr. 1, 2016
Non Interest Expense [Member]
Property, Plant and Equipment [Line Items]
Asset held for sale, impairment charge on one of the properties			$ 142,000

Bank Premises and Equipment (Fu

Bank Premises and Equipment (Future Minimum Rental Payments) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Property Plant And Equipment [Abstract]
2018 Lease obligation	$ 1,171
2019 Lease obligation	975
2020 Lease obligation	790
2021 Lease obligation	617
2022 Lease obligation	564
Lease obligation thereafter	5,113
Lease obligation	9,230
2018 Sublease rental income	79
2019 Sublease rental income	81
2020 Sublease rental income	81
2021 Sublease rental income	20
Sublease rental income	261
2018 Net rental expense	1,092
2019 Net rental expense	894
2020 Net rental expense	709
2021 Net rental expense	597
2022 Net rental expense	564
Net rental thereafter	5,113
Net rental expense	$ 8,969

Bank Premises and Equipment (81

Bank Premises and Equipment (Future Minimum Rental Payments) (Parenthetical) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Rent expense in connection with leases	$ 1,087,000	$ 716,000	$ 627,000

Deposits (Narrative) (Details)

Deposits (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Time Deposits	$ 201,623,000	$ 182,595,000
Interest Expense, Time Deposits	2,570,000	2,156,000	$ 1,920,000
Brokered Deposits	19,447,000	13,567,000
Related Party Deposit Liabilities	20,262,000	19,279,000
Demand Deposit [Member]
Demand deposit overdrafts reclassified as loans	$ 136,000	$ 285,000

Deposits (Time Deposits By Matu

Deposits (Time Deposits By Maturity Date) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Time Deposits, Total	$ 201,623,000	$ 182,595,000
Time Deposits Less Than $250,000 [Member]
Maturing in 2018	74,304,000
Maturing in 2019	38,810,000
Maturing in 2020	24,380,000
Maturing in 2021	16,987,000
Maturing in 2022	8,984,000
Maturing thereafter	965,000
Time Deposits, Total	164,430,000
Time Deposits $250,000 or More [Member]
Maturing in 2018	29,736,000
Maturing in 2019	4,811,000
Maturing in 2020	885,000
Maturing in 2021	309,000
Maturing in 2022	1,452,000
Time Deposits, Total	$ 37,193,000

Short-term Borrowings (Narrativ

Short-term Borrowings (Narrative) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Short term borrowings	$ 34,611,000
Current borrowing available	436,821,000
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Short term borrowings	$ 34,611,000	$ 0
Short-term debt, weighted average interest rate	1.54%
Other Correspondent Banks [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	$ 15,000,000

Long-term Debt (Narrative) (Det

Long-term Debt (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Maturities Of Long Term Debt [Abstract]
Long-term debt outstanding	$ 12,352	$ 13,581
Long-Term Debt, Aggregate Principal Amounts Due, 2018	223
Long-Term Debt, Aggregate Principal Amounts Due, 2019	10,235
Long-Term Debt, Aggregate Principal Amounts Due, 2020	246
Long-Term Debt, Aggregate Principal Amounts Due, 2021	258
Long-Term Debt, Aggregate Principal Amounts Due, 2022	271
Long-Term Debt, Aggregate Principal Amounts Due, Thereafter	$ 1,119

Long-term Debt (Long-term Debt

Long-term Debt (Long-term Debt Outstanding by Maturity Date) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt outstanding	$ 12,352	$ 13,581
Maturing in 2017 [Member]
Debt Instrument [Line Items]
Long-term debt outstanding		$ 1,016
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	3.03%	3.03%
Maturing In 2019 [Member]
Debt Instrument [Line Items]
Long-term debt outstanding	$ 10,000	$ 10,000
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	1.87%	1.87%
Maturing in 2026 [Member]
Debt Instrument [Line Items]
Long-term debt outstanding	$ 2,295	$ 2,504
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	4.80%	4.80%
Maturing in 2027 [Member]
Debt Instrument [Line Items]
Long-term debt outstanding	$ 57	$ 61
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	6.71%	6.71%

Subordinated Debt (Narrative) (

Subordinated Debt (Narrative) (Details) - USD ($)	Dec. 19, 2017	Dec. 09, 2015	Dec. 31, 2017	Dec. 31, 2015
Subordinated debt issuance			$ 10,000,000	$ 7,500,000
Subordinated Notes Due 2028 [Member] | Subordinated Debt [Member]
Subordinated debt issuance	$ 10,000,000
Debt instrument, interest rate, effective percentage	5.25%
Debt Instrument, Description of Variable Rate Basis			The 2017 Notes will bear interest at a rate of 5.25% per year for the first five years and then float at the Wall Street Journal’s Prime Rate plus 0.50%, provided that the interest rate applicable to the outstanding principal balance will at no times be less than 5.0%.
Debt Instrument, Payment Terms			Interest will be payable semi-annually in arrears on January 15 and July 15 of each year, beginning on July 15, 2018, for the first five years after issuance and will be payable quarterly in arrears thereafter on January 15, April 15, July 15, and October 15.
Debt instrument, maturity date			Jan. 1, 2028
Debt Instrument, Redemption, Description			The 2017 Notes will mature on January 1, 2028 and are redeemable in whole or in part, without premium or penalty, at any time on or after December 21, 2022, and prior to January 1, 2028. Additionally, Mid Penn may redeem the 2017 Notes in whole at any time, or in part from time to time, upon at least 30 days’ notice if: (i) a change or prospective change in law occurs that could prevent Mid Penn from deducting interest payable on the 2017 Notes for U.S. federal income tax purposes; (ii) an event occurs that precludes the 2017 Notes from being recognized as Tier 2 capital for regulatory capital purposes; or (iii) Mid Penn becomes required to register as an investment company under the Investment Company Act of 1940, as amended. In the event of a redemption described in the previous sentence, Mid Penn will redeem the 2017 Notes at 100% of the principal amount of the 2017 Notes, plus accrued and unpaid interest thereon to but excluding the date of redemption.
Notes payable to related parties			$ 1,450,000
Subordinated Notes Due 2028 [Member] | Subordinated Debt [Member] | WSJ Prime Rate [Member]
Debt instrument, interest rate, effective percentage	5.00%
Debt Instrument, Basis Spread on Variable Rate	0.50%
Subordinated Notes Due 2025 [Member] | Subordinated Debt [Member]
Subordinated debt issuance		$ 7,500,000
Debt instrument, interest rate, effective percentage		5.15%
Debt Instrument, Description of Variable Rate Basis			The 2015 Notes bear interest at a rate of 5.15% per year for the first five years and then float at the Wall Street Journal’s Prime Rate plus 0.50%, provided that the interest rate applicable to the outstanding principal balance will at no times be less than 4.0%.
Debt Instrument, Payment Terms			Interest will be payable quarterly in arrears on January 1, April 1, July 1 and October 1 of each year, and began on January 1, 2016.
Debt instrument, maturity date			Dec. 9, 2025
Debt Instrument, Redemption, Description			The 2015 Notes will mature on December 9, 2025 and are redeemable in whole or in part, without premium or penalty, at any time on or after December 9, 2020, and prior to December 9, 2025. Additionally, Mid Penn may redeem the 2015 Notes in whole at any time, or in part from time to time, upon at least 30 days’ notice if: (i) a change or prospective change in law occurs that could prevent Mid Penn from deducting interest payable on the 2015 Notes for U.S. federal income tax purposes; (ii) an event occurs that precludes the 2015 Notes from being recognized as Tier 2 capital for regulatory capital purposes; or (iii) Mid Penn becomes required to register as an investment company under the Investment Company Act of 1940, as amended, in each case at 100% of the principal amount of the 2015 Notes, plus accrued and unpaid interest thereon to but excluding the date of redemption.
Notes payable to related parties			$ 1,930,000
Subordinated Notes Due 2025 [Member] | Subordinated Debt [Member] | WSJ Prime Rate [Member]
Debt instrument, interest rate, effective percentage		4.00%
Debt Instrument, Basis Spread on Variable Rate		0.50%

Fair Value Measurement (Assets

Fair Value Measurement (Assets Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 93,465	$ 133,625
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	856	2,920
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	92,609	130,705
U.S. Treasury and U.S. government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	38,730	47,012
U.S. Treasury and U.S. government agencies [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		1,864
U.S. Treasury and U.S. government agencies [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	38,730	45,148
Mortgage-backed U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	25,831	25,619
Mortgage-backed U.S. Government Agencies [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	25,831	25,619
State and political subdivision obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	27,043	58,838
State and political subdivision obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	27,043	58,838
Corporate debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,005	1,000
Corporate debt securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,005	1,000
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	856	1,156
Equity Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 856	1,056
Equity Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		$ 100

Fair Value Measurement (Fair Va

Fair Value Measurement (Fair Value Measurements, Nonrecurring) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Impaired Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 6,090	$ 2,404
Impaired Loan [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	6,090	2,404
Foreclosed Assets Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		135
Foreclosed Assets Held for Sale [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		135
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	126	144
Mortgage Servicing Rights [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 126	$ 144

Fair Value Measurement (Fair 90

Fair Value Measurement (Fair Value Inputs, Assets, Quantitative Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Impaired Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 6,090	$ 2,404
Fair Value Measurements, Valuation Techniques	Appraisal of collateral	Appraisal of collateral
Fair Value Disclosure, Unobservable Input Range	Appraisal adjustments	Appraisal adjustments
Impaired Loan [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 6,090	$ 2,404
Foreclosed Assets Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		$ 135
Fair Value Measurements, Valuation Techniques	Appraisal of collateral	Appraisal of collateral
Fair Value Disclosure, Unobservable Input Range	Appraisal adjustments	Appraisal adjustments
Foreclosed Assets Held for Sale [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		$ 135
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 126	$ 144
Fair Value Measurements, Valuation Techniques	Multiple of annual service fee	Multiple of annual service fee
Fair Value Disclosure, Unobservable Input Range	Estimated prepayment speed based on rate and term	Estimated prepayment speed based on rate and term
Mortgage Servicing Rights [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 126	$ 144
Minimum [Member] | Appraisal of Collateral [Member] | Impaired Loan [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	6.00%	11.00%
Minimum [Member] | Appraisal of Collateral [Member] | Foreclosed Assets Held for Sale [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	0.00%	26.00%
Minimum [Member] | Multiple of Annual Service [Member] | Mortgage Servicing Rights [Member] | Unobservable Input Estimated Prepayment Speed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Prepayment Rate	70.00%	70.00%
Maximum [Member] | Appraisal of Collateral [Member] | Impaired Loan [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	51.00%	70.00%
Maximum [Member] | Appraisal of Collateral [Member] | Foreclosed Assets Held for Sale [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	0.00%	31.00%
Maximum [Member] | Multiple of Annual Service [Member] | Mortgage Servicing Rights [Member] | Unobservable Input Estimated Prepayment Speed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Prepayment Rate	100.00%	100.00%
Weighted Average [Member] | Appraisal of Collateral [Member] | Impaired Loan [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	28.00%	30.00%
Weighted Average [Member] | Appraisal of Collateral [Member] | Foreclosed Assets Held for Sale [Member] | Unobservable Input - Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	0.00%	27.00%
Weighted Average [Member] | Multiple of Annual Service [Member] | Mortgage Servicing Rights [Member] | Unobservable Input Estimated Prepayment Speed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Prepayment Rate	98.00%	98.00%

Fair Value Measurement (Fair 91

Fair Value Measurement (Fair Value, by Balance Sheet Grouping) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale investment securities	$ 93,465	$ 133,625
Held to maturity investment securities	100,483	0
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	23,514	45,973
Available for sale investment securities	93,465	133,625
Held to maturity investment securities	101,356
Net loans and leases	902,798	806,741
Restricted investment in bank stocks	4,384	2,443
Accrued interest receivable	4,564	3,928
Mortgage servicing rights	126	144
Deposits	1,023,568	935,373
Short-term borrowings	34,611
Long-term debt	12,352	13,581
Subordinated debt	17,338	7,414
Accrued interest payable	645	515
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	23,514	45,973
Available for sale investment securities	93,465	133,625
Held to maturity investment securities	100,483
Net loans and leases	917,081	824,293
Restricted investment in bank stocks	4,384	2,443
Accrued interest receivable	4,564	3,928
Mortgage servicing rights	126	144
Deposits	1,026,830	935,075
Short-term borrowings	34,611
Long-term debt	11,692	13,614
Subordinated debt	17,358	7,534
Accrued interest payable	$ 645	$ 515

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deposits	$ 1,026,830	$ 935,075
Long-term debt	11,692	13,614
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	917,081	824,293
Subordinated debt	17,358	7,534
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	902,798	806,741
Deposits	1,023,568	935,373
Long-term debt	12,352	13,581
Subordinated debt	17,338	7,414
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	917,081	824,293
Deposits	1,026,830	935,075
Long-term debt	11,692	13,614
Subordinated debt	$ 17,358	$ 7,534

Postretirement Benefit Plans (N

Postretirement Benefit Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Postretirement benefit health insurance reimbursable premium	$ 5,000
Defined Benefit Postretirement Health Insurance [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, minimum retirement age	55 years
Defined Benefit Plan, Minimum Service Period Requirement	20 years
Defined benefit plan, coverage period	5 years
Defined Benefit Postretirement Life Insurance [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, minimum retirement age	55 years
Defined Benefit Plan, Minimum Service Period Requirement	20 years
Defined Benefit Plan, Benefit Description, Until Age 65	The insurance amount will be $50,000 until age 65.
Life insurance coverage amount until age 65	$ 50,000,000
Defined Benefit Plan, Benefit Description, After Age 65	After age 65, the insurance amount will decrease by $5,000 per year until age 74.
Decrease in Coverage Amount After Age 65	$ 5,000,000
Life insurance coverage amount	5,000,000
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Unrecognized Prior Service Cost Generated By Adoption of the Plan	274,000,000
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Prior Service Cost, before Tax	22,000,000
Defined Benefit Plan, Accumulated Benefit Obligation	1,116,000	$ 1,122,000
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year	22,000
Cash surrender value of bank owned life insurance	3,905,000,000	3,834,000,000
Defined Benefit Postretirement Health And Life Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation	508,000	$ 540,000
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year	$ 25,000,000

Postretirement Benefit Plans 94

Postretirement Benefit Plans (Net Funded Status) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Postretirement Health And Life Coverage [Member]
Change in benefit obligations:
Benefit obligations	$ 540	$ 572
Change in benefit obligations: Service cost	4	4	$ 13
Change in benefit obligations: Interest cost	20	23	32
Change in benefit obligations: Change in experience	(11)	2
Change in benefit obligations: Change in assumptions	20	13
Change in benefit obligations/fair value of plan assets: Benefit payments	(65)	(74)
Benefit obligations	508	540	572
Change in fair value of plan assets:
Change in fair value of plan assets: Employer contributions	65	74
Change in benefit obligations/fair value of plan assets: Benefit payments	(65)	(74)
Funded status at year end	(508)	(540)
Director's Retirement Plan [Member]
Change in benefit obligations:
Benefit obligations	1,122	1,150
Change in benefit obligations: Service cost	35	34	33
Change in benefit obligations: Interest cost	43	46	45
Change in benefit obligations: Actuarial gain (loss)	6	(13)
Change in benefit obligations: Change in assumptions	2	(4)
Change in benefit obligations/fair value of plan assets: Benefit payments	(92)	(91)
Benefit obligations	1,116	1,122	$ 1,150
Change in fair value of plan assets:
Change in fair value of plan assets: Employer contributions	92	91
Change in benefit obligations/fair value of plan assets: Benefit payments	(92)	(91)
Funded status at year end	$ (1,116)	$ (1,122)

Postretirement Benefit Plans (A

Postretirement Benefit Plans (Amounts Recognized in Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Postretirement Health And Life Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued benefit liability	$ 508	$ 540
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued benefit liability	$ 1,116	$ 1,122

Postretirement Benefit Plans 96

Postretirement Benefit Plans (Amounts Recognized in Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Postretirement Health And Life Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain), pretax	$ (22)	$ (31)
Net prior service cost, pretax	(174)	(209)
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain), pretax	67	60
Net prior service cost, pretax	$ 22	$ 43

Postretirement Benefit Plans 97

Postretirement Benefit Plans (Net Periodic Benefit (Income) Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Postretirement Health And Life Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 4	$ 4	$ 13
Interest Cost	20	23	32
Amortization of prior service cost	(35)	(35)
Net periodic postretirement benefit (income) cost	(11)	(8)	45
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	35	34	33
Interest Cost	43	46	45
Amortization of prior service cost	22	22	22
Net periodic postretirement benefit (income) cost	$ 100	$ 102	$ 100

Postretirement Benefit Plans 98

Postretirement Benefit Plans (Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Postretirement Health And Life Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.50%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	2.50%	3.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.00%	4.25%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	3.00%	3.25%	3.00%
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.50%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.00%	4.25%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Change In Consumer Price Index	1.50%	2.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Changes In Consumer Price Index	2.00%	2.25%	2.25%

Postretirement Benefit Plans (H

Postretirement Benefit Plans (Health Care Cost Trend Rates) (Details) - Defined Benefit Postretirement Health And Life Coverage [Member]	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate assumed for next year	6.00%	6.00%	5.50%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.40%	5.50%	5.50%
Year that the rate reaches the ultimate trend rate	2,024	2,018	2,016

Postretirement Benefit Plans (E

Postretirement Benefit Plans (Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates) (Details) - Defined Benefit Postretirement Health And Life Coverage [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	$ 3
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	2
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	$ 4

Postretirement Benefit Plans101

Postretirement Benefit Plans (Expected Benefit Payments) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)
Defined Benefit Postretirement Health And Life Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
1/1/2018 to 12/31/2018	$ 60,000
1/1/2019 to 12/31/2019	61,000
1/1/2020 to 12/31/2020	55,000
1/1/2021 to 12/31/2021	31,000
1/1/2022 to 12/31/2022	32,000
1/1/2023 to 12/31/2027	160,000
Defined contribution plan, employer discretionary contribution amount	73,000
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
1/1/2018 to 12/31/2018	95,000
1/1/2019 to 12/31/2019	95,000
1/1/2020 to 12/31/2020	96,000
1/1/2021 to 12/31/2021	107,000
1/1/2022 to 12/31/2022	104,000
1/1/2023 to 12/31/2027	413,000
Defined contribution plan, employer discretionary contribution amount	$ 94,000

Other Benefit Plans (Narrative)

Other Benefit Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Shares purchased by participants	1,345
Average purchase price per share of shares purchased	$ 31.136
Deferred Compensation Arrangement with Individual, by Type of Compensation, Pension and Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Deferred Compensation Arrangement with Individual, Recorded Liability	$ 125,000	$ 143,000
Deferred compensation arrangement with individual, compensation expense	5,000	6,000	$ 9,000
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, associated expense	0	0	0
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Deferred Compensation Arrangement with Individual, Recorded Liability	683,000	606,000
Deferred compensation arrangement with individual, compensation expense	25,000	21,000	17,000
Cash surrender value of bank owned life insurance	3,905,000,000	3,834,000,000
Salary Continuation Agreement [Member]
Defined Benefit Plan Disclosure [Line Items]
Deferred Compensation Arrangement with Individual, Recorded Liability		246,000	254,000
Deferred compensation arrangement with individual, compensation expense	$ 17,000	17,000	16,000
Defined benefit plan, maximum coverage period	15 years
Cash surrender value of bank owned life insurance	$ 1,317,000	1,284,000
Split Dollar Life Insurance Arrangements [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash surrender value of bank owned life insurance	1,375,000	1,360,000
Split Dollar Life Insurance Arrangements [Member] | Phoenix Bancorp Inc. [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash surrender value of bank owned life insurance	3,924,000	3,838,000
401(k) Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, associated expense	$ 383,000	$ 362,000	$ 321,000

Other Benefit Plans (Schedule o

Other Benefit Plans (Schedule of Employees Eligible to Participate in Employee Stock Purchase Plan) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Pension Plans And Defined Benefit Postretirement Plans Disclosure [Abstract]
ESPP shares purchased	3,578	4,465	4,162
Average purchase price per share	$ 29.027	$ 18.520	$ 15.865

Federal Income Taxes (Net Defer

Federal Income Taxes (Net Deferred Tax Asset) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Allowance for loan and lease losses	$ 1,597	$ 2,442
Deferred Tax Assets, Loan Fees	105	82
Deferred Tax Assets, Deferred Compensation	221	341
Deferred Tax Assets, Benefit plans	320	565
Deferred Tax Assets, Unrealized loss on securities	574	1,504
Deferred Tax Assets, Nonaccrual interest		955
Deferred Tax Assets, Business combination adjustments	358	720
Deferred Tax Assets, Sale/leaseback adjustment	72
Deferred Tax Assets, Other	108	177
Deferred Tax Assets, Gross, Total	3,355	6,786
Deferred Tax Liabilities, Depreciation	(619)	(1,175)
Deferred Tax Liabilities, Bond accretion	(9)	(117)
Deferred Tax Liabilities, Goodwill and intangibles	(329)	(500)
Deferred Tax Liabilities, Prepaid expenses	(333)	(312)
Deferred Tax Liabilities, Business combination adjustments	(176)	(367)
Deferred Tax Liabilities, Other	(1)	(29)
Deferred Tax Liabilities, Gross, Total	(1,467)	(2,500)
Deferred tax asset, net	$ 1,888	$ 4,286

Federal Income Taxes (Narrative

Federal Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Federal tax rate		34.00%	34.00%	34.00%
Rate change adjustment		$ 1,169,000
Unrecognized tax benefits that would affect the effective income tax rate if recognized		0
Income Tax Examination, Penalties and Interest Expense		0	$ 0	$ 0
Income Tax Examination, Penalties and Interest Accrued		$ 0	$ 0
Scenario Forecast [Member]
Income Taxes [Line Items]
Federal tax rate	21.00%

Federal Income Taxes (Provision

Federal Income Taxes (Provision for Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current expense									$ 2,672	$ 2,613	$ 647
Deferred expense (benefit)									1,828	(336)	997
Provision for income taxes	$ 2,170	$ 871	$ 769	$ 690	$ 638	$ 526	$ 593	$ 520	$ 4,500	$ 2,277	$ 1,644

Federal Income Taxes (Schedule

Federal Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Provision at the expected statutory rate									$ 3,940,000	$ 3,428,000	$ 2,779,000
Effect of tax-exempt income									(668,000)	(1,089,000)	(1,105,000)
Effect of investment in life insurance									(89,000)	(90,000)	(91,000)
Nondeductible interest									30,000	41,000	37,000
Nondeductible merger and acquisition expense									191,000		34,000
Rate change adjustment									1,169,000
Other items									(73,000)	(13,000)	(10,000)
Provision for income taxes	$ 2,170,000	$ 871,000	$ 769,000	$ 690,000	$ 638,000	$ 526,000	$ 593,000	$ 520,000	$ 4,500,000	$ 2,277,000	$ 1,644,000

Regulatory Matters (Details)

Regulatory Matters (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital for Capital Adequacy (To Average Assets), Ratio		4.00%
Common Equity Tier 1 Capital for Capital Adequacy (to Risk Weighted Assets), ratio		4.50%
Tier 1 Capital for Capital Adequacy (To Risk Weighted Assets), Ratio		6.00%	4.00%
Total Capital for Capital Adequacy (To Risk Weighted Assets), Ratio		8.00%
Capital Conservation Buffer Percentage		2.50%
Common Equity Tier 1 Capital Ratio with Capital Conservation Buffer		7.00%
Tier 1 Capital Ratio with Capital Conservation Buffer		8.50%
Total Capital Ratio with Capital Conservation Buffer		10.50%
Annual Phase in Percentage of Capital Conservation Buffer		0.625%
Capital Conservation Buffer Phase in Beginning Year Month		2016-01
Capital Conservation Buffer Phase in End Year Month		2019-01
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval		$ 5,259
Corporation [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital (To Average Assets)		74,417	$ 70,431
Common Equity Tier 1 Capital (to Risk Weighted Assets)		74,417	70,431
Tier 1 Capital (To Risk Weighted Assets)		74,417	70,431
Total Capital (To Risk Weighted Assets)		$ 99,466	$ 85,148
Tier 1 Capital (to Average Assets), Ratio		6.50%	6.80%
Common Equity Tier 1 Capital (to Risk Weighted Assets), ratio		8.40%	9.10%
Tier 1 Capital (To Risk Weighted Assets), Ratio		8.40%	9.10%
Total Capital (To Risk Weighted Assets), Ratio		11.30%	11.00%
Tier 1 Capital for Capital Adequacy (To Average Assets)	[1]	$ 45,857	$ 41,595
Common Equity Tier 1 Capital for Capital Adequacy (to Risk Weighted Assets)	[1]	50,661	39,641
Tier 1 Capital for Capital Adequacy (To Risk Weighted Assets)	[1]	63,877	51,244
Total Capital for Capital Adequacy (To Risk Weighted Assets)	[1]	$ 81,498	$ 66,714
Tier 1 Capital for Capital Adequacy (To Average Assets), Ratio	[1]	4.00%	4.00%
Common Equity Tier 1 Capital for Capital Adequacy (to Risk Weighted Assets), ratio	[1]	5.75%	5.125%
Tier 1 Capital for Capital Adequacy (To Risk Weighted Assets), Ratio	[1]	7.25%	6.625%
Total Capital for Capital Adequacy (To Risk Weighted Assets), Ratio	[1]	9.25%	8.625%
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital (To Average Assets)		$ 88,294	$ 77,026
Common Equity Tier 1 Capital (to Risk Weighted Assets)		88,294	77,026
Tier 1 Capital (To Risk Weighted Assets)		88,294	77,026
Total Capital (To Risk Weighted Assets)		$ 96,005	$ 84,329
Tier 1 Capital (to Average Assets), Ratio		7.70%	7.40%
Common Equity Tier 1 Capital (to Risk Weighted Assets), ratio		10.00%	10.00%
Tier 1 Capital (To Risk Weighted Assets), Ratio		10.00%	10.00%
Total Capital (To Risk Weighted Assets), Ratio		10.90%	10.90%
Tier 1 Capital for Capital Adequacy (To Average Assets)	[1]	$ 45,846	$ 41,568
Common Equity Tier 1 Capital for Capital Adequacy (to Risk Weighted Assets)	[1]	50,661	39,611
Tier 1 Capital for Capital Adequacy (To Risk Weighted Assets)	[1]	63,877	51,205
Total Capital for Capital Adequacy (To Risk Weighted Assets)	[1]	$ 81,498	$ 66,663
Tier 1 Capital for Capital Adequacy (To Average Assets), Ratio	[1]	4.00%	4.00%
Common Equity Tier 1 Capital for Capital Adequacy (to Risk Weighted Assets), ratio	[1]	5.75%	5.125%
Tier 1 Capital for Capital Adequacy (To Risk Weighted Assets), Ratio	[1]	7.25%	6.625%
Total Capital for Capital Adequacy (To Risk Weighted Assets), Ratio	[1]	9.25%	8.625%
Tier 1 Capital to be Well-Capitalized Under Prompt Corrective Action Provision (To Average Assets)		$ 57,308	$ 51,960
Common Equity Tier 1 Capital to be Well-Capitalized Under Prompt Corrective Action Provision (To Risk Weighted Assets)		57,269	50,239
Tier 1 Capital to be Well-Capitalized Under Prompt Corrective Action Provision (To Risk Weighted Assets)		70,485	61,832
Total Capital to be Well-Capitalized Under Prompt Corrective Action Provision (To Risk Weighted Assets)		$ 88,106	$ 77,291
Tier 1 Capital to be Well-Capitalized Under Prompt Corrective Action Provision (To Average Assets), Ratio		5.00%	5.00%
Common Equity Tier 1 Capital to be Well-Capitalized Under Prompt Corrective Action Provision (To Risk Weighted Assets), ratio		6.50%	6.50%
Tier 1 Capital to be Well-Capitalized Under Prompt Corrective Action Provision (To Risk Weighted Assets), Ratio		8.00%	8.00%
Total Capital to be Well-Capitalized Under Prompt Corrective Action Provision (To Risk Weighted Assets), Ratio		10.00%	10.00%
[1]	Minimum amounts and ratios as of December 31, 2017 include the second year phase in of the capital conservation buffer of 1.25 percent required by the Basel III framework. At December 31, 2016, the minimum amounts and ratios included the first year phase in of the capital conservation buffer of 0.625 percent required by the Basel III framework.

Regulatory Matters (Parenthetic

Regulatory Matters (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Second Year Phased In [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum capital required including percentage of capital conservation buffer	1.25%
First Year Phased In [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum capital required including percentage of capital conservation buffer		0.625%

Concentration of Risk and Of110

Concentration of Risk and Off-Balance Sheet Risk (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Concentration Risk [Line Items]
Commitments to extend credit	$ 199,240,000	$ 201,749,000
Balance of loans sold under the program	$ 7,314,000	9,206,000
Concentration risk, benchmark description	10% or more of the Bank's total net loans outstanding
Benchmark - Loans Receivable, Net [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	51.10%
Financial Standby Letters of Credit [Member]
Concentration Risk [Line Items]
Commitments to extend credit	$ 20,496,000	$ 14,000,000

Common Stock (Details)

Common Stock (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 25, 2014
Employee [Member]
Class of Stock [Line Items]
Restricted shares, vesting period	4 years
Director [Member]
Class of Stock [Line Items]
Restricted shares, vesting period	12 months
Dividend Reinvestment Plan [Member]
Class of Stock [Line Items]
Shares authorized per plan	330,750
2014 Restricted Stock Plan [Member]
Class of Stock [Line Items]
Shares authorized per plan				100,000
Shares granted, net	26,955
Shares granted	10,440
Shares forfeited		470
Unrecognized compensation cost related to all non-vested share-based compensation awards	$ 440,000
2014 Restricted Stock Plan [Member] | Employee [Member]
Class of Stock [Line Items]
Shares granted	6,040	7,540	5,475
2014 Restricted Stock Plan [Member] | Director [Member]
Class of Stock [Line Items]
Shares granted	4,400

Common Stock (Schedule of Compe

Common Stock (Schedule of Compensation Expense and Related Tax Benefits for Restricted Stock Awards Recognized) (Details) - 2014 Restricted Stock Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense	$ 145	$ 53	$ 28
Income tax benefit	(49)	(18)	(10)
Net income effect	$ 96	$ 35	$ 18

Common Stock (Schedule of Non-V

Common Stock (Schedule of Non-Vested Restricted Stock) (Details) - 2014 Restricted Stock Plan [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Non-vested at January 1, 2016	13,055
Shares, Vested	(3,996)
Shares, Cancelled		(470)
Shares, Granted	10,440
Shares, Non-vested at December 31, 2016	19,499	13,055
Weighted-Average Grant Date Fair Value, Non-vested at January 1, 2016	$ 17.66
Weighted-Average Grant Date Fair Value, Vested	17.38
Weighted-Average Grant Date Fair Value, Granted	26.65
Weighted-Average Grant Date Fair Value, Non-vested at December 31, 2016	$ 22.54	$ 17.66

Preferred Stock (Small Business

Preferred Stock (Small Business Lending Fund) (Narrative) (Details) - USD ($)	Jan. 19, 2016	Dec. 15, 2015	Dec. 09, 2015	Jan. 03, 2013	Dec. 31, 2015	Mar. 01, 2015
Phoenix Bancorp Inc. [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Issued						1,750
Preferred Class B [Member]
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage				7.00%
Payments for Repurchase of Redeemable Preferred Stock			$ 5,123,000
Stock issued during period, shares, new issues				5,000
Proceeds from issuance of private placement				$ 5,000,000
Preferred stock, redemption price per share			$ 1,024.67
Preferred Stock Redemption Price Per Share Excluding Dividends Declared But Unpaid			$ 1,020
Series C Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage	1.00%
Payments for Repurchase of Redeemable Preferred Stock		$ 1,754,000			$ 1,750,000
Preferred Stock, Shares Issued						1,750
Preferred stock, liquidation preference per share						$ 1,000
Series C Preferred Stock [Member] | Phoenix Bancorp Inc. [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Issued						1,750
Preferred stock, liquidation preference per share						$ 1,000

Parent Company Statements (Cond

Parent Company Statements (Condensed Balance Sheets) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash and cash equivalents	$ 23,514,000	$ 45,973,000	$ 13,284,000	$ 9,882,000
Investment in subsidiaries	277,000	321,000
Other assets	3,594,000	3,215,000
Total Assets	1,170,354,000	1,032,599,000
Subordinated debt	17,338,000	7,414,000
Other liabilities	6,137,000	5,249,000
Shareholders' equity	75,703,000	70,467,000	70,068,000	59,130,000
Total Liabilities and Shareholders' Equity	1,170,354,000	1,032,599,000
Parent Company [Member]
Cash and cash equivalents	4,686,000	780,000	$ 564,000	$ 554,000
Equity investments		545,000
Investment in subsidiaries	89,581,000	77,029,000
Other assets		40,000
Total Assets	94,267,000	78,394,000
Subordinated debt	17,338,000	7,414,000
Other liabilities	1,226,000	513,000
Shareholders' equity	75,703,000	70,467,000
Total Liabilities and Shareholders' Equity	$ 94,267,000	$ 78,394,000

Parent Company Statements (C116

Parent Company Statements (Condensed Statement of Income and Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other expenses									$ (5,063)	$ (4,683)	$ (4,122)
Income before income tax and equity in undistributed (loss) earnings of subsidiaries	$ 2,671	$ 3,120	$ 3,114	$ 2,684	$ 2,714	$ 2,427	$ 2,615	$ 2,325	11,589	10,081	8,172
Income tax benefit	(2,170)	(871)	(769)	(690)	(638)	(526)	(593)	(520)	(4,500)	(2,277)	(1,644)
NET INCOME									7,089	7,804	6,528
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS	$ 501	$ 2,249	$ 2,345	$ 1,994	$ 2,076	$ 1,901	$ 2,022	$ 1,805	7,089	7,804	6,038
Comprehensive income									8,209	3,139	6,827
Series B Preferred Stock [Member]
Preferred stock dividends and redemption premium											473
Preferred stock dividends											373
Series C Preferred Stock [Member]
Preferred stock dividends											17
Parent Company [Member]
Dividends from subsidiaries									9,657	2,871	5,662
Other income									19	33	19
Total Income									9,676	2,904	5,681
Other expenses									(1,899)	(606)	(695)
Total Expense									(1,899)	(606)	(695)
Income before income tax and equity in undistributed (loss) earnings of subsidiaries									7,777	2,298	4,986
Equity in undistributed (loss) earnings of subsidiaries									(1,136)	5,311	1,346
Income before income tax									6,641	7,609	6,332
Income tax benefit									448	195	196
NET INCOME									7,089	7,804	6,528
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS									7,089	7,804	6,038
Comprehensive income									$ 8,209	$ 3,139	6,827
Parent Company [Member] | Series B Preferred Stock [Member]
Preferred stock dividends and redemption premium											473
Parent Company [Member] | Series C Preferred Stock [Member]
Preferred stock dividends											$ 17

Parent Company Statements (C117

Parent Company Statements (Condensed Statement of Cash Flows) (Details) - USD ($)	Dec. 15, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income		$ 7,089,000	$ 7,804,000	$ 6,528,000
Decrease (increase) in other assets		(380,000)	(99,000)	333,000
(Decrease) increase in other liabilities		(172,000)	4,000	(771,000)
Net Cash Provided By Operating Activities		11,895,000	21,848,000	13,174,000
Proceeds from the sale of investment securities		52,932,000	111,390,000	37,142,000
Net Cash Used In Investing Activities		(163,797,000)	(86,799,000)	(38,903,000)
Dividends paid		(2,204,000)	(2,452,000)	(1,785,000)
Deferred financing fees paid for subordinated debt issuance		(85,000)		(85,000)
Subordinated debt issuance		10,000,000		7,500,000
Net Cash Provided By Financing Activities		129,443,000	97,640,000	29,131,000
Net (decrease) increase in cash and cash equivalents		(22,459,000)	32,689,000	3,402,000
Cash and cash equivalents, beginning of year		45,973,000	13,284,000	9,882,000
Cash and cash equivalents, end of year		23,514,000	45,973,000	13,284,000
Employee [Member]
Stock Purchase Plan share issuance		104,000	82,000	66,000
Director [Member]
Stock Purchase Plan share issuance		42,000
Series B Preferred Stock [Member]
Preferred stock redemption				(5,000,000)
Series C Preferred Stock [Member]
Preferred stock redemption	$ (1,754,000)			(1,750,000)
Parent Company [Member]
Net income		7,089,000	7,804,000	6,528,000
Equity in undistributed loss (earnings) of subsidiaries		1,136,000	(5,311,000)	(1,346,000)
Decrease (increase) in other assets		240,000	59,000	(14,000)
(Decrease) increase in other liabilities		626,000	457,000	(665,000)
Net Cash Provided By Operating Activities		9,091,000	3,009,000	4,503,000
Net cash paid for acquisition				(2,949,000)
Proceeds from the sale of investment securities		618,000
Investment in subsidiary		(12,600,000)
Net Cash Used In Investing Activities		(11,982,000)		(2,949,000)
Dividends paid		(3,264,000)	(2,875,000)	(2,175,000)
Deferred financing fees paid for subordinated debt issuance		(85,000)		(85,000)
Subordinated debt issuance		10,000,000		7,500,000
Net Cash Provided By Financing Activities		6,797,000	(2,793,000)	(1,544,000)
Net (decrease) increase in cash and cash equivalents		3,906,000	216,000	10,000
Cash and cash equivalents, beginning of year		780,000	564,000	554,000
Cash and cash equivalents, end of year		4,686,000	780,000	564,000
Parent Company [Member] | Employee [Member]
Stock Purchase Plan share issuance		104,000	$ 82,000	66,000
Parent Company [Member] | Director [Member]
Stock Purchase Plan share issuance		$ 42,000
Parent Company [Member] | Series B Preferred Stock [Member]
Preferred stock redemption premium				(100,000)
Preferred stock redemption				(5,000,000)
Parent Company [Member] | Series C Preferred Stock [Member]
Preferred stock redemption				$ (1,750,000)

Recent Accounting Pronouncem118

Recent Accounting Pronouncements (Narrative) (Details)	Dec. 31, 2017USD ($)
Accounting Changes And Error Corrections [Abstract]
Equity investments (excluding restricted investments in bank stocks)	$ 856,000

Summary of Quarterly Consoli119

Summary of Quarterly Consolidated Financial Data (Unaudited) (Quarterly Condensed Financials) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Data [Abstract]
Interest Income	$ 11,304	$ 11,150	$ 10,879	$ 10,559	$ 10,531	$ 10,125	$ 9,859	$ 9,697	$ 43,892	$ 40,212	$ 36,490
Interest Expense	1,817	1,634	1,469	1,384	1,402	1,367	1,316	1,282	6,304	5,367	4,607
Net Interest Income	9,487	9,516	9,410	9,175	9,129	8,758	8,543	8,415	37,588	34,845	31,883
Provision for loan and lease losses	100		100	125	550	585	395	340	325	1,870	1,065
Net Interest Income After Provision for Loan and Lease Losses	9,387	9,516	9,310	9,050	8,579	8,173	8,148	8,075	37,263	32,975	30,818
Noninterest Income	1,331	1,564	1,362	1,436	1,875	1,419	1,398	1,232	5,693	5,924	4,113
Noninterest Expense	8,047	7,960	7,558	7,802	7,740	7,165	6,931	6,982	31,367	28,818	26,759
INCOME BEFORE PROVISION FOR INCOME TAXES	2,671	3,120	3,114	2,684	2,714	2,427	2,615	2,325	11,589	10,081	8,172
Provision for Income Taxes	2,170	871	769	690	638	526	593	520	4,500	2,277	1,644
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS	$ 501	$ 2,249	$ 2,345	$ 1,994	$ 2,076	$ 1,901	$ 2,022	$ 1,805	$ 7,089	$ 7,804	$ 6,038
Basic Earnings Per Common Share	$ 0.12	$ 0.53	$ 0.55	$ 0.47	$ 0.49	$ 0.45	$ 0.48	$ 0.43	$ 1.67	$ 1.85	$ 1.47
Cash Dividends Declared	$ 0.38	$ 0.13	$ 0.13	$ 0.13	$ 0.22	$ 0.12	$ 0.12	$ 0.22	$ 0.77	$ 0.68	$ 0.44

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions	Jan. 16, 2018	Jan. 08, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Scottdale's assets prior to merger			$ 1,170,354,000	$ 1,032,599,000
Scottdale's deposits prior to merger			1,023,568,000	$ 935,373,000
Scottdale Bank and Trust Company [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Date of acquisition		Jan. 8, 2018
Plan of merger agreement, date		Mar. 29, 2017
Per share price		$ 1,166
Merger agreement exchange ratio		3888.00%
Common stock shares issued to acquire the company		1.9
Cash paid to acquire the business		$ 2,800,000
Business acquisition, transaction cost		$ 66,972,000
Period prior to closing of merger for calculating average price		8 days
First Priority Financial Corp. [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Plan of merger agreement, date	Jan. 16, 2018
Business acquisition, proforma assets	$ 2,000,000,000
Shares of acquirer ratio of common stock	34.81%
Scottdale Bank and Trust Company [Member]
Subsequent Event [Line Items]
Scottdale's assets prior to merger			260,735,000
Scottdale's loans prior to merger			69,328,000
Scottdale's deposits prior to merger			$ 210,658,000