Subordinated Debt and Trust Preferred Securities	12 Months Ended
Subordinated Debt and Trust Preferred Securities	Dec. 31, 2022
Debt Disclosure [Abstract]
Subordinated Debt and Trust Preferred Securities	Subordinated Debt and Trust Preferred Securities Subordinated Debt Issued December 2015 On December 9, 2015, Mid Penn sold $7.5 million of subordinated notes (the "2015 Notes") due in 2025. The 2015 Notes were 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. On August 8, 2022, Mid Penn redeemed all of the 2015 Notes. Given that the 2015 Notes were in the seventh year since issuance, 60% of the principal balance of the notes would have been treated as Tier 2 capital for regulatory capital purposes as of December 31, 2022. The 2015 Notes paid interest at a rate of 5.15% per year for the first five years outstanding, including the three months ended March, 31, 2020. Beginning January 1, 2021, the 2015 Notes bore interest at a floating rate based on the Wall Street Journal’s Prime Rate plus 0.50%, provided that the interest rate applicable to the outstanding principal balance was at no time less than 4.00%. Interest was payable quarterly in arrears on January 1, April 1, July 1 and October 1 of each year, beginning on January 1, 2016. Subordinated Debt Assumed November 2021 with the Riverview Acquisition On November 30, 2021, Mid Penn completed its acquisition of Riverview and assumed $25.0 million of Subordinated Notes (the "Riverview Notes"). In accordance with purchase accounting principles, the Riverview Notes were assigned a fair value premium of $2.3 million. The notes are treated as Tier 2 capital for regulatory reporting purposes. The Riverview Notes were entered into by Riverview on October 6, 2020 with certain qualified institutional buyers and accredited institutional investors. The Riverview Notes have a maturity date of October 15, 2030 and initially bear interest, payable semi-annually, at a fixed annual rate of 5.75% per annum until October 15, 2025. Commencing on that date, the interest rate applicable to the outstanding principal amount due will be reset quarterly to an interest rate per annum equal to the then current three-month secured overnight financing rate ("SOFR") plus 563 bp, payable quarterly until maturity. Mid Penn may redeem the Notes at par, in whole or in part, at its option, anytime beginning on October 15, 2025. Trust Preferred Securities Assumed November 2021 with the Riverview Acquisition In connection with the Riverview Acquisition, Mid Penn assumed the subordinated debentures that Riverview had assumed in its acquisition of CBT Financial Corp. ("CBT") on October 1, 2017 (the "CBT 2017 Notes"). In 2003 a trust formed by CBT which issued $5.2 million of floating rate trust preferred securities as part of a pooled offering of such securities. CBT was eligible to redeem the subordinated debentures, in whole but not in part, beginning in 2008 at a price of 100% of face value. The subordinated debentures were required to be redeemed no later than 2033. Similarly, in 2005, a trust formed by CBT issued $4.1 million of fixed rate trust preferred securities as part of a pooled offering of such securities (the "CBT 2015 Notes"). CBT was eligible to redeem the subordinated debentures, in whole but not in part, beginning in 2010 at a price of 100% of face value. In December 2022, Mid Penn redeemed all of the CBT 2017 Notes and CBT 2015 Notes. Subordinated Debt Issued December 2020 On December 22, 2020, Mid Penn entered into agreements for and sold, at 100% of their principal amount, an aggregate of $12.2 million of its Subordinated Notes due December 2030 (the "December 2020 Notes") on a private placement basis to accredited investors. The December 2020 Notes are treated as Tier 2 capital for regulatory capital purposes. The December 2020 Notes bear interest at a rate of 4.50% per year for the first five years and then float at the Wall Street Journal’s Prime Rate, provided that the interest rate applicable to the outstanding principal balance during the period the December 2020 Notes are floating will at no time be less than 4.50%. Interest is payable quarterly in arrears on March 31, June 30, September 30 and December 31, of each year, beginning on March 31, 2021. The December 2020 Notes will mature on December 31, 2030 and are redeemable, in whole or in part, without premium or penalty, on any interest payment date on or after December 31, 2025 and prior to December 31, 2030, subject to any required regulatory approvals. Additionally, if (i) all or any portion of the December 2020 Notes cease to be deemed Tier 2 Capital, (ii) interest on the December 2020 Notes fails to be deductible for United States federal income tax purposes or (iii) Mid Penn will be considered an "investment company," Mid Penn may redeem the December 2020 Notes, in whole but not in part, by giving 10 days’ notice to the holders of the December 2020 Notes. In the event of a redemption described in the previous sentence, Mid Penn will redeem the December 2020 Notes at 100% of the principal amount of the December 2020 Notes, plus accrued and unpaid interest thereon to but excluding the date of redemption. Holders of the December 2020 Notes may not accelerate the maturity of the December 2020 Notes, except upon the bankruptcy, insolvency, liquidation, receivership or similar event of Mid Penn or Mid Penn Bank, its principal banking subsidiary. Related parties held $750 thousand of the December 2020 Notes as of December 31, 2022 and 2021. Subordinated Debt Issued March 2020 On March 20, 2020, Mid Penn entered into agreements with accredited investors who purchased $15.0 million aggregate principal amount of Mid Penn Subordinated Notes due March 2030 (the "March 2020 Notes"). As a result of Mid Penn’s merger with Riverview on November 30, 2021, $6.9 million of the March 2020 Notes balance was redeemed as Riverview was a holder of the March 2020 Notes. The balance of March 2020 Notes outstanding as of December 31, 2021 was $8.1 million. The March 2020 Notes held at December 31, 2022 are treated as Tier 2 capital for regulatory capital purposes. The March 2020 Notes bear interest at a rate of 4.00% per year for the first five years and then float at the Wall Street Journal’s Prime Rate, provided that the interest rate applicable to the outstanding principal balance during the period the March 2020 Notes are floating will at no time be less than 4.25%. Interest is payable semi-annually in arrears on June 30 and December 30 of each year, beginning on June 30, 2020, for the first five years after issuance and will be payable quarterly in arrears thereafter on March 30, June 30, September 30 and December 30. The March 2020 Notes will mature on March 30, 2030 and are redeemable in whole or in part, without premium or penalty, at any time on or after March 30, 2025 and prior to March 30, 2030. Additionally, if all or any portion of the March 2020 Notes cease to be deemed Tier 2 Capital, Mid Penn may redeem, on any interest payment date, all or part of the 2020 Notes. In the event of a redemption described in the previous sentence, Mid Penn will redeem the March 2020 Notes at 100% of the principal amount of the March 2020 Notes, plus accrued and unpaid interest thereon to but excluding the date of redemption. Holders of the March 2020 Notes may not accelerate the maturity of the March 2020 Notes, except upon the bankruptcy, insolvency, liquidation, receivership or similar event of Mid Penn or Mid Penn Bank, its principal banking subsidiary. Related parties held $1.7 million of the March 2020 Notes as of December 31, 2022 and 2021. Subordinated Debt Issued December 2017 On December 19, 2017, Mid Penn entered into agreements with investors to purchase $10.0 million aggregate principal amount of its Subordinated Notes due 2028 (the "2017 Notes"). The 2017 Notes are treated as Tier 2 capital for regulatory capital purposes. The 2017 Notes 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 5.00%. Interest is 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, 2022 and 2021, related parties held $1.5 million of the 2017 Notes.