Summary of Significant Accounting Policies (Narrative) (Details)			3 Months Ended		6 Months Ended		9 Months Ended	12 Months Ended		30 Months Ended
	Nov. 30, 2021 USD ($) shares	May 04, 2021 USD ($) $ / shares shares	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) Apartment shares	Jun. 30, 2021 USD ($) shares	Dec. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2022 USD ($)
Loans and leases receivable, net, carrying amount			$ 3,163,157,000		$ 3,163,157,000		$ 3,089,799,000	$ 3,089,799,000		$ 3,163,157,000
Loans and leases, net of unearned interest			895,855,000		895,855,000		1,010,039,000	1,010,039,000		895,855,000
Bank premises and equipment held for sale			2,574,000		2,574,000		3,907,000	3,907,000		2,574,000
Bank premises and equipment held for sale, write off expense					$ 705,000
Asset held for sale, description					Bank premises and equipment designated as held for sale are carried at the lower of cost or market value, and at June 30, 2022 and December 31, 2021, totaled $2,574,000 and $3,907,000, respectively. These balances are related to the December 7, 2021 announcement of a Retail Network Optimization Plan under which the Bank announced its intention to close certain retail locations throughout its expanded footprint. The branch closures occurred on March 4, 2022.  Adjustments to record these held for sale assets at the lower of cost or fair value related to the held for sale properties were included in post-acquisition restructuring expenses and totaled $874,000 for the year ended December 31, 2021. During the six months ended June 30, 2022, Mid Penn had a write-off expense of obsolete bank premises and equipment held for sale of $705,000, as a result of branch closures during the first quarter of 2022, as previously announced on a Form 8-K dated December 7, 2021. There were no impairment charges recorded during the six months ended June 30, 2022 or 2021.
Residential real estate held in other real estate owned			0		$ 0		0	0		0
Foreclosure proceedings in process			752,000		752,000		0	0		752,000
Carrying value of investment in limited partnership			80,000		$ 80,000		102,000	102,000		80,000
Number of apartments under the project | Apartment					37
Limited partner capital contribution			7,506,000		$ 7,506,000					7,506,000
Limited partner capital contribution, funded period					3 years
Project investment amortization period					10 years
Total LIHTCs amount awarded for the project								8,530,000
Annual LIHTCs amount under the housing project							853,000	$ 853,000
Project investment recognition period								10 years
Amortization expense			521,000	$ 276,000	$ 1,002,000	$ 557,000
Goodwill			113,835,000		$ 113,835,000		113,835,000	$ 113,835,000		113,835,000
Number of antidilutive shares | shares					0	0
Follow-on Public Offering [Member]
Common shares issued through follow-on public offering, shares | shares		2,990,000
Common stock, price per share | $ / shares		$ 25.00
Net proceeds received after underwriting discount and other estimated offering expenses		$ 70,238,000
Proceeds from follow-on common stock public offering		$ 74,750,000				$ 70,238,000
First Priority Financial Corp. [Member]
Goodwill acquired					$ 39,744,000			39,744,000
Riverview [Member]
Goodwill	$ 50,995,000
Goodwill acquired					50,995,000			50,995,000
Stock issued during period, shares | shares	4,519,776
Riverview [Member] | Follow-on Public Offering [Member]
Stock issued during period, shares | shares		4,519,776
Riverview [Member] | Rabbi Trust
Benefit plan liabilities related to compensation arrangements			6,680,000		6,680,000		7,708,000	7,708,000		6,680,000
Scottdale Bank and Trust Company [Member]
Goodwill acquired					19,178,000			19,178,000
Phoenix Bancorp Incorporated [Member]
Goodwill acquired					3,918,000			3,918,000
Core Deposit Intangible [Member]
Intangible assets, net			5,780,000		5,780,000		7,282,000	7,282,000		5,780,000
Amortization expense					$ 797,000	543,000
Core Deposit Intangible, Amortization Period					10 years
Impairment of core deposit intangible					$ 0
Increase in core deposit					$ 711,680,000			711,680,000
Finite Lived Intangible Assets Growth Percentage					28.00%
Other Assets [Member]
Carrying value of investment in limited partnership			5,585,000		$ 5,585,000		5,962,000	5,962,000		5,585,000
Other Assets [Member] | Riverview [Member] | Rabbi Trust
Cash balance			6,706,000		6,706,000		7,708,000	7,708,000		6,706,000
Non Interest Expense [Member]
Asset held for sale, impairment charge					0	$ 0		874,000
Reserve for Off-balance Sheet Activities [Member]
Valuation allowances and reserves, balance			$ 74,000		$ 74,000		72,000	72,000		$ 74,000
Maximum [Member]
Non-residential consumer loans charged off on contractual basis in event of bankruptcy, in period			120 days		120 days					120 days
Commercial Portfolio [Member]
Loan terms					1 year
Loan to value ratio			80.00%		80.00%					80.00%
Residential Portfolio [Member] | Maximum [Member]
Loan terms					30 years
Loan to value ratio			100.00%		100.00%					100.00%
Loan to value ratio, exposure after private mortgage insurance					85.00%
Small Business Administration [Member] | PPP Loans [Member]
Loans and leases receivable, net, carrying amount			$ 4,966,000		$ 4,966,000		111,286,000	111,286,000		$ 4,966,000
Loan guarantee description					The PPP loans, which are 100% guaranteed by the SBA, have up to a five-year term to maturity and carry a low interest rate of 1% throughout the loan term.
Nonrefundable loan processing fees received					$ 3,640,000		17,997,000	17,997,000	$ 20,883,000	42,520,000
Deferred loan processing fees			171,000		171,000		3,811,000	3,811,000		171,000
Loan processing fees			3,640,000					6,244,000
Loss reserve					$ 0			0
Small Business Administration [Member] | Maximum [Member] | PPP Loans [Member]
Processing fee percentage					5.00%
Small Business Administration [Member] | Minimum [Member] | PPP Loans [Member]
Processing fee percentage					1.00%
Equity Securities [Member]
Equity securities, fair value			454,000		$ 454,000		$ 500,000	$ 500,000		454,000
Equity Securities [Member] | ASU 2016-01 [Member]
Equity securities, fair value			454,000		$ 454,000				$ 500,000	$ 454,000
Equity securities sold			$ 0	$ 0
Home equity lines of credit [Member] | Maximum [Member]
Loan terms					20 years
Loan to value ratio			85.00%		85.00%					85.00%
Home Equity Lines Of Credit [Member] | Maximum [Member]
Loan terms					10 years