Revenue Recognition (Policies)	12 Months Ended
Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Revenue Recognition	Revenue Recognition Mid Penn recognizes revenues when earned based upon (i) contractual terms as transactions occur, or (ii) as related services are provided and collectability is reasonably assured. The largest source of revenue for Mid Penn is interest income, which is primarily recognized on an accrual basis according to a written contract, such as loan and lease agreements or investment securities contracts. Mid Penn earns noninterest income through a variety of financial and transactional services such as trust and wealth management services, deposit account transaction fees, ATM debit card fees, and mortgage banking fees. Revenue is recorded for noninterest income based on the contractual terms for the service or transaction performed. In certain circumstances, noninterest income is reported net of associated expenses. On January 1, 2018, Mid Penn adopted FASB ASU 2014-09, Revenue from Contracts with Customers (Topic 606). Results for reporting periods beginning after January 1, 2018 are presented under ASC 606, while prior period amounts were not adjusted and continue to be reported in accordance with the previous accounting guidance under ASC 605.This ASU establishes principles for reporting information about the nature, timing, and uncertainty of revenue and cash flows arising from the entity’s contracts to provide goods and services to customers. ASU 2014-09 applies primarily to transactional-based non-interest income revenue streams and excludes mortgage banking income, earnings from cash surrender value of life insurance, and gains on SBA loans. Mid Penn’s non-interest income revenue streams of income from fiduciary activities, service charges on deposits, ATM debit card interchange income, merchant service fees and certain components of other income are within the scope of Topic 606 and are discussed in greater detail below. Income from Fiduciary Activities Income from fiduciary activities consist of investment management fee income, brokerage transaction fee income, and estate fee income. Investment management fee income consists of advisory fees that are based on market values of clients’ managed portfolios and transaction fees for fiduciary services performed, both of which are recognized as earned. Brokerage transaction fee income includes advisory fees which are recognized as earned on a monthly basis and transaction fees that are recognized when transactions occur. Payment is typically received in the following month. Estate fee income is recognized as services are performed over the service period, generally eighteen months. Service Charges on Deposits Service charges on deposits consist of cash management, overdraft, non-sufficient fund fees and other service charges on deposit accounts. Revenue is primarily transactional and recognized when earned, which is at the time the respective initiating transaction occurs and the related service charge is subsequently processed. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to the customers’ accounts. ATM Debit Card Interchange Income ATM debit card interchange income consists interchange fees earned when Mid Penn’s debit cards are processed through card payments networks. The interchange fee is calculated as a percentage of the total electronic funds transfer (EFT) transaction plus a per-transaction fee, which varies based on the type of card used, the method used to process the EFT transaction, and the type of business at which the transaction was processed. Revenue is recognized daily as transactions occur and interchange fees are subsequently processed. Payment for interchange activity is received primarily daily, while some fees are aggregated and payment is received in the following month. Merchant Services Income Merchant services income is processed through a third party provider with whom Mid Penn has partnered to provide merchant services to its business customers. Fees are charged to merchants to process their debit card transactions, cash advance services, and other related products. Mid Penn receives a percentage of the revenue generated from each joint customer relationship after the third party has collected the fee income from the merchant. Payment is primarily received in the following month. Other Income Certain aspects of other income, such as credit card royalties, check orders, and letter of credit fees, are within the scope of Topic 606. These fees are primarily transactional, and revenue is recognized when transactions occur and the related services are subsequently processed. Payment is primarily received immediately or in the following month. Mid Penn does not exercise significant judgements in the recognition of income, as typically income is not recognized until the performance obligation has been satisfied. Mid Penn has not recognized any assets from the costs to obtain or fulfill a contract with customers for revenue streams that fall within the guidance of Topic 606.

Revenue Recognition (Policies)

12 Months Ended

Dec. 31, 2018

Revenue From Contract With Customer [Abstract]

Mid Penn recognizes revenues when earned based upon (i) contractual terms as transactions occur, or (ii) as related services are provided and collectability is reasonably assured. The largest source of revenue for Mid Penn is interest income, which is primarily recognized on an accrual basis according to a written contract, such as loan and lease agreements or investment securities contracts. Mid Penn earns noninterest income through a variety of financial and transactional services such as trust and wealth management services, deposit account transaction fees, ATM debit card fees, and mortgage banking fees. Revenue is recorded for noninterest income based on the contractual terms for the service or transaction performed. In certain circumstances, noninterest income is reported net of associated expenses.

On January 1, 2018, Mid Penn adopted FASB ASU 2014-09, Revenue from Contracts with Customers (Topic 606). Results for reporting periods beginning after January 1, 2018 are presented under ASC 606, while prior period amounts were not adjusted and continue to be reported in accordance with the previous accounting guidance under ASC 605.This ASU establishes principles for reporting information about the nature, timing, and uncertainty of revenue and cash flows arising from the entity’s contracts to provide goods and services to customers. ASU 2014-09 applies primarily to transactional-based non-interest income revenue streams and excludes mortgage banking income, earnings from cash surrender value of life insurance, and gains on SBA loans.

Mid Penn’s non-interest income revenue streams of income from fiduciary activities, service charges on deposits, ATM debit card interchange income, merchant service fees and certain components of other income are within the scope of Topic 606 and are discussed in greater detail below.

Income from Fiduciary Activities

Income from fiduciary activities consist of investment management fee income, brokerage transaction fee income, and estate fee income. Investment management fee income consists of advisory fees that are based on market values of clients’ managed portfolios and transaction fees for fiduciary services performed, both of which are recognized as earned. Brokerage transaction fee income includes advisory fees which are recognized as earned on a monthly basis and transaction fees that are recognized when transactions occur. Payment is typically received in the following month. Estate fee income is recognized as services are performed over the service period, generally eighteen months.

Service Charges on Deposits

Service charges on deposits consist of cash management, overdraft, non-sufficient fund fees and other service charges on deposit accounts. Revenue is primarily transactional and recognized when earned, which is at the time the respective initiating transaction occurs and the related service charge is subsequently processed. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to the customers’ accounts.

ATM Debit Card Interchange Income

ATM debit card interchange income consists interchange fees earned when Mid Penn’s debit cards are processed through card payments networks. The interchange fee is calculated as a percentage of the total electronic funds transfer (EFT) transaction plus a per-transaction fee, which varies based on the type of card used, the method used to process the EFT transaction, and the type of business at which the transaction was processed. Revenue is recognized daily as transactions occur and interchange fees are subsequently processed. Payment for interchange activity is received primarily daily, while some fees are aggregated and payment is received in the following month.

Merchant Services Income

Merchant services income is processed through a third party provider with whom Mid Penn has partnered to provide merchant services to its business customers. Fees are charged to merchants to process their debit card transactions, cash advance services, and other related products. Mid Penn receives a percentage of the revenue generated from each joint customer relationship after the third party has collected the fee income from the merchant. Payment is primarily received in the following month.

Other Income

Certain aspects of other income, such as credit card royalties, check orders, and letter of credit fees, are within the scope of Topic 606. These fees are primarily transactional, and revenue is recognized when transactions occur and the related services are subsequently processed. Payment is primarily received immediately or in the following month.

Mid Penn does not exercise significant judgements in the recognition of income, as typically income is not recognized until the performance obligation has been satisfied. Mid Penn has not recognized any assets from the costs to obtain or fulfill a contract with customers for revenue streams that fall within the guidance of Topic 606.