Financial Instruments with Off- Balance Sheet Risk (Notes)	9 Months Ended
Sep. 30, 2017
Financial Instruments with Off-Balance Sheet Risk [Abstract]
Financial Instruments Disclosure [Text Block]	Financial Instruments with Off-Balance Sheet Risk Derivatives and Hedging Activities - Risk Management Objective of Using Derivatives Peoples is exposed to certain risks arising from both its business operations and economic conditions. Peoples principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. Peoples manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities and through the use of derivative financial instruments. Specifically, Peoples enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known or expected cash amounts, the value of which are determined by interest rates. Peoples’ derivative financial instruments are used to manage differences in the amount, timing, and duration of Peoples' known or expected cash receipts and its known or expected cash payments principally related to certain variable rate borrowings. Peoples also has interest rate derivatives that result from a service provided to certain qualifying customers and, therefore, are not used to manage interest rate risk in Peoples' assets or liabilities. Peoples manages a matched book with respect to customer-related derivative financial instruments in order to minimize its net risk exposure resulting from such transactions. Fair Values of Derivative Instruments on the Balance Sheet Peoples' fair value of the derivative financial instruments was $4.8 million in an asset position and $3.9 million in a liability position at September 30, 2017, and there was $5.0 million in an asset position and $3.2 million in a liability position at December 31, 2016. The amounts are recorded in other assets, and accrued expenses and other liabilities on the consolidated balance sheet at the periods indicated. Cash Flow Hedges of Interest Rate Risk Peoples' objectives in using interest rate derivatives are to add stability to interest income and expense, and to manage its exposure to interest rate movements. To accomplish these objectives, Peoples has entered into interest rate swaps as part of its interest rate risk management strategy. These interest rate swaps are designated as cash flow hedges and involve the receipt of variable rate amounts from a counterparty in exchange for Peoples making fixed payments. As of September 30, 2017, Peoples had seven interest rate swaps with a notional value of $60.0 million associated with Peoples' cash outflows for various FHLB advances. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of each derivative is initially reported in accumulated other comprehensive income ("AOCI") (outside of earnings), net of tax, and subsequently reclassified to earnings when the hedged transaction affects earnings, and the ineffective portion of changes in the fair value of the derivative is recognized directly in earnings. Peoples assesses the effectiveness of each hedging relationship by comparing the changes in cash flows of the derivative hedging instrument with the changes in cash flows of the designated hedged transaction. Peoples hedged its exposure to the variability in future cash flows for forecasted transactions over a maximum period of 13 months (excluding forecasted transactions related to the payment of variable interest on existing financial instruments). Peoples entered into the seven interest rate swap contracts, described above, whereby Peoples will pay a fixed rate of interest for up to ten years while receiving a floating rate component of interest equal to the three-month LIBOR rate. The received floating rate component is intended to offset the rate on the rolling three-month FHLB advances. Amounts reported in AOCI related to derivatives will be reclassified to interest income or expense as interest payments are made or received on Peoples' variable-rate assets or liabilities. During the three and nine months ended September 30, 2017, and September 30, 2016, Peoples had no reclassifications to interest expense. Peoples estimates that no interest expense amount will be reclassified in the fourth quarter of 2017 prior to adoption of the new accounting standards. The amount of accumulated other comprehensive pre-tax income for Peoples' cash flow hedges was $1.0 million at September 30, 2017. There were no pre-tax net losses recorded for the nine months ended September 30, 2017. Additionally, Peoples had no reclassifications to earnings in the three months or nine months ended September 30, 2017 or September 30, 2016. Non-Designated Hedges Peoples maintains an interest rate protection program for commercial loan customers, which was established in 2010. Under this program, Peoples provides its customer with a fixed-rate loan while creating a variable-rate asset for Peoples by the customer entering into an interest rate swap with Peoples on terms that match the loan. Peoples offsets its risk exposure by entering into an offsetting interest rate swap with an unaffiliated institution. These interest rate swaps do not qualify as designated hedges; therefore, each swap is accounted for as a standalone derivative. Peoples had interest rate swaps associated with commercial loans with a notional value of $334.2 million and fair value of $3.5 million of equally offsetting assets and liabilities at September 30, 2017, and a notional value of $247.3 million and fair value of $3.2 million of equally offsetting assets and liabilities at December 31, 2016. These interest rate swaps did not have a material impact on Peoples' results of operation or financial condition.

Financial Instruments with Off-Balance Sheet Risk

Derivatives and Hedging Activities - Risk Management Objective of Using Derivatives

Peoples is exposed to certain risks arising from both its business operations and economic conditions. Peoples principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. Peoples manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities and through the use of derivative financial instruments. Specifically, Peoples enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known or expected cash amounts, the value of which are determined by interest rates. Peoples’ derivative financial instruments are used to manage differences in the amount, timing, and duration of Peoples' known or expected cash receipts and its known or expected cash payments principally related to certain variable rate borrowings. Peoples also has interest rate derivatives that result from a service provided to certain qualifying customers and, therefore, are not used to manage interest rate risk in Peoples' assets or liabilities. Peoples manages a matched book with respect to customer-related derivative financial instruments in order to minimize its net risk exposure resulting from such transactions.

Fair Values of Derivative Instruments on the Balance Sheet

Peoples' fair value of the derivative financial instruments was $4.8 million in an asset position and $3.9 million in a liability position at September 30, 2017, and there was $5.0 million in an asset position and $3.2 million in a liability position at December 31, 2016. The amounts are recorded in other assets, and accrued expenses and other liabilities on the consolidated balance sheet at the periods indicated.

Cash Flow Hedges of Interest Rate Risk

Peoples' objectives in using interest rate derivatives are to add stability to interest income and expense, and to manage its exposure to interest rate movements. To accomplish these objectives, Peoples has entered into interest rate swaps as part of its interest rate risk management strategy. These interest rate swaps are designated as cash flow hedges and involve the receipt of variable rate amounts from a counterparty in exchange for Peoples making fixed payments. As of September 30, 2017, Peoples had seven interest rate swaps with a notional value of $60.0 million associated with Peoples' cash outflows for various FHLB advances.

For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of each derivative is initially reported in accumulated other comprehensive income ("AOCI") (outside of earnings), net of tax, and subsequently reclassified to earnings when the hedged transaction affects earnings, and the ineffective portion of changes in the fair value of the derivative is recognized directly in earnings. Peoples assesses the effectiveness of each hedging relationship by comparing the changes in cash flows of the derivative hedging instrument with the changes in cash flows of the designated hedged transaction.

Peoples hedged its exposure to the variability in future cash flows for forecasted transactions over a maximum period of 13 months (excluding forecasted transactions related to the payment of variable interest on existing financial instruments). Peoples entered into the seven interest rate swap contracts, described above, whereby Peoples will pay a fixed rate of interest for up to ten years while receiving a floating rate component of interest equal to the three-month LIBOR rate. The received floating rate component is intended to offset the rate on the rolling three-month FHLB advances. Amounts reported in AOCI related to derivatives will be reclassified to interest income or expense as interest payments are made or received on Peoples' variable-rate assets or liabilities. During the three and nine months ended September 30, 2017, and September 30, 2016, Peoples had no reclassifications to interest expense. Peoples estimates that no interest expense amount will be reclassified in the fourth quarter of 2017 prior to adoption of the new accounting standards.

The amount of accumulated other comprehensive pre-tax income for Peoples' cash flow hedges was $1.0 million at September 30, 2017. There were no pre-tax net losses recorded for the nine months ended September 30, 2017. Additionally, Peoples had no reclassifications to earnings in the three months or nine months ended September 30, 2017 or September 30, 2016.

Non-Designated Hedges

Peoples maintains an interest rate protection program for commercial loan customers, which was established in 2010. Under this program, Peoples provides its customer with a fixed-rate loan while creating a variable-rate asset for Peoples by the customer entering into an interest rate swap with Peoples on terms that match the loan. Peoples offsets its risk exposure by entering into an offsetting interest rate swap with an unaffiliated institution. These interest rate swaps do not qualify as designated hedges; therefore, each swap is accounted for as a standalone derivative. Peoples had interest rate swaps associated with commercial loans with a notional value of $334.2 million and fair value of $3.5 million of equally offsetting assets and liabilities at September 30, 2017, and a notional value of $247.3 million and fair value of $3.2 million of equally offsetting assets and liabilities at December 31, 2016. These interest rate swaps did not have a material impact on Peoples' results of operation or financial condition.