Fair Value Measurement - Schedule of Fair Value Measurements, Nonrecurring (Details) - Nonrecurring $ in Thousands	Sep. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Individually evaluated loans, net of ACL
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, nonrecurring	$ 15,752	$ 21,171
Individually evaluated loans, net of ACL \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, nonrecurring	0	0
Individually evaluated loans, net of ACL \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, nonrecurring	0	0
Individually evaluated loans, net of ACL \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, nonrecurring	$ 15,752	$ 21,171
Individually evaluated loans, net of ACL \| Level 3 \| Minimum \| Measurement Input, Appraised Value \| Unobservable Input - Appraisal Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan, Held-for-sale (as percent)	0.08	0
Individually evaluated loans, net of ACL \| Level 3 \| Maximum \| Measurement Input, Appraised Value \| Unobservable Input - Appraisal Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan, Held-for-sale (as percent)	1	1
Individually evaluated loans, net of ACL \| Level 3 \| Weighted Average \| Measurement Input, Appraised Value \| Unobservable Input - Appraisal Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan, Held-for-sale (as percent)	0.249	0.056
Foreclosed assets held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, nonrecurring	$ 9,346	$ 44
Foreclosed assets held for sale \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, nonrecurring	0	0
Foreclosed assets held for sale \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, nonrecurring	0	0
Foreclosed assets held for sale \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, nonrecurring	$ 9,346	$ 44
Foreclosed assets held for sale \| Level 3 \| Minimum \| Measurement Input, Appraised Value \| Unobservable Input - Appraisal Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan, Held-for-sale (as percent)	0.22	0.26
Foreclosed assets held for sale \| Level 3 \| Maximum \| Measurement Input, Appraised Value \| Unobservable Input - Appraisal Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan, Held-for-sale (as percent)	0.31	0.26
Foreclosed assets held for sale \| Level 3 \| Weighted Average \| Measurement Input, Appraised Value \| Unobservable Input - Appraisal Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan, Held-for-sale (as percent)	0.239	0.260

MID PENN BANCORP INC 10-Q