Investment Securities (Schedule of Fair Value and Unrealized Loss on Investments in a Continuous Unrealized Loss Position) (Details) $ in Thousands	Dec. 31, 2020 USD ($) security	Dec. 31, 2019 USD ($) security
Schedule of Investments [Line Items]
Available for sale securities, Less than 12 Months: Number of Securities \| security	2	5
Available for sale securities, Less than 12 Months: Fair Value	$ 3,497	$ 6,295
Available for sale securities, Less than 12 Months: Unrealized Losses	$ 4	$ 28
Available for sale securities, 12 Months or More: Number of Securities \| security	0	21
Available for sale securities, 12 Months or More: Fair Value		$ 22,585
Available for sale securities, 12 Months or More: Unrealized Losses		$ 155
Available for sale securities, Total: Number of Securities \| security	2	26
Available for sale securities, Total: Fair Value	$ 3,497	$ 28,880
Available for sale securities, Total: Unrealized Losses	$ 4	$ 183
Held to maturity securities, Less than 12 Months: Number of Securities \| security	11	27
Held to maturity securities, Less than 12 Months: Fair Value	$ 6,586	$ 38,852
Held to maturity securities, Less than 12 Months: Unrealized Losses	$ 22	$ 267
Held to maturity securities, 12 Months or More: Number of Securities \| security	0	14
Held to maturity securities, 12 Months or More: Fair Value		$ 14,049
Held to maturity securities, 12 Months or More: Unrealized Losses		$ 68
Held to maturity securities, Total: Number of Securities \| security	11	41
Held to maturity securities, Total: Fair Value	$ 6,586	$ 52,901
Held to maturity securities, Total: Unrealized Losses	$ 22	$ 335
Available for sale securities and Held to maturity securities, Less than 12 Months: Number of Securities \| security	13	32
Available for sale securities and Held to maturity securities, Less than 12 Months: Fair Value	$ 10,083	$ 45,147
Available for sale securities and Held to maturity securities, Less than 12 Months: Unrealized Losses	$ 26	$ 295
Available for sale securities and Held to maturity securities,, 12 Months or More: Number of Securities \| security	0	35
Available for sale securities and Held to maturity securities, 12 Months or More: Fair Value		$ 36,634
Available for sale securities and Held to maturity securities, 12 Months or More: Unrealized Losses		$ 223
Available for sale securities and Held to maturity securities, Total: Number of Securities \| security	13	67
Available for sale securities and Held to maturity securities, Total: Fair Value	$ 10,083	$ 81,781
Available for sale securities and Held to maturity securities, Total: Unrealized Losses	$ 26	$ 518
U.S. Government Agencies [Member]
Schedule of Investments [Line Items]
Available for sale securities, Less than 12 Months: Number of Securities \| security		4
Available for sale securities, Less than 12 Months: Fair Value		$ 4,652
Available for sale securities, Less than 12 Months: Unrealized Losses		$ 24
Available for sale securities, 12 Months or More: Number of Securities \| security		7
Available for sale securities, 12 Months or More: Fair Value		$ 11,982
Available for sale securities, 12 Months or More: Unrealized Losses		$ 46
Available for sale securities, Total: Number of Securities \| security		11
Available for sale securities, Total: Fair Value		$ 16,634
Available for sale securities, Total: Unrealized Losses		$ 70
Mortgage-backed U.S. Government Agencies [Member]
Schedule of Investments [Line Items]
Available for sale securities, Less than 12 Months: Number of Securities \| security		1
Available for sale securities, Less than 12 Months: Fair Value		$ 1,643
Available for sale securities, Less than 12 Months: Unrealized Losses		$ 4
Available for sale securities, 12 Months or More: Number of Securities \| security		14
Available for sale securities, 12 Months or More: Fair Value		$ 10,603
Available for sale securities, 12 Months or More: Unrealized Losses		$ 109
Available for sale securities, Total: Number of Securities \| security		15
Available for sale securities, Total: Fair Value		$ 12,246
Available for sale securities, Total: Unrealized Losses		$ 113
Held to maturity securities, Less than 12 Months: Number of Securities \| security	8	6
Held to maturity securities, Less than 12 Months: Fair Value	$ 5,336	$ 8,445
Held to maturity securities, Less than 12 Months: Unrealized Losses	$ 15	$ 35
Held to maturity securities, 12 Months or More: Number of Securities \| security	0	13
Held to maturity securities, 12 Months or More: Fair Value		$ 11,050
Held to maturity securities, 12 Months or More: Unrealized Losses		$ 67
Held to maturity securities, Total: Number of Securities \| security	8	19
Held to maturity securities, Total: Fair Value	$ 5,336	$ 19,495
Held to maturity securities, Total: Unrealized Losses	$ 15	$ 102
Corporate debt securities [Member]
Schedule of Investments [Line Items]
Available for sale securities, Less than 12 Months: Number of Securities \| security	2
Available for sale securities, Less than 12 Months: Fair Value	$ 3,497
Available for sale securities, Less than 12 Months: Unrealized Losses	$ 4
Available for sale securities, 12 Months or More: Number of Securities \| security	0
Available for sale securities, Total: Number of Securities \| security	2
Available for sale securities, Total: Fair Value	$ 3,497
Available for sale securities, Total: Unrealized Losses	$ 4
Held to maturity securities, Less than 12 Months: Number of Securities \| security	1
Held to maturity securities, Less than 12 Months: Fair Value	$ 449
Held to maturity securities, Less than 12 Months: Unrealized Losses	$ 1
Held to maturity securities, 12 Months or More: Number of Securities \| security	0
Held to maturity securities, Total: Number of Securities \| security	1
Held to maturity securities, Total: Fair Value	$ 449
Held to maturity securities, Total: Unrealized Losses	$ 1
U.S. Treasury and U.S. government agencies [Member]
Schedule of Investments [Line Items]
Held to maturity securities, Less than 12 Months: Number of Securities \| security		18
Held to maturity securities, Less than 12 Months: Fair Value		$ 29,024
Held to maturity securities, Less than 12 Months: Unrealized Losses		$ 219
Held to maturity securities, 12 Months or More: Number of Securities \| security		1
Held to maturity securities, 12 Months or More: Fair Value		$ 2,999
Held to maturity securities, 12 Months or More: Unrealized Losses		$ 1
Held to maturity securities, Total: Number of Securities \| security		19
Held to maturity securities, Total: Fair Value		$ 32,023
Held to maturity securities, Total: Unrealized Losses		$ 220
State and political subdivision obligations [Member]
Schedule of Investments [Line Items]
Held to maturity securities, Less than 12 Months: Number of Securities \| security	2	3
Held to maturity securities, Less than 12 Months: Fair Value	$ 801	$ 1,383
Held to maturity securities, Less than 12 Months: Unrealized Losses	$ 6	$ 13
Held to maturity securities, 12 Months or More: Number of Securities \| security	0	0
Held to maturity securities, Total: Number of Securities \| security	2	3
Held to maturity securities, Total: Fair Value	$ 801	$ 1,383
Held to maturity securities, Total: Unrealized Losses	$ 6	$ 13

Available for sale securities and held to maturity securities continuous unrealized loss position accumulated loss.

No definition available.

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Namespace Prefix:	mpb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Available for sale securities and held to maturity securities continuous unrealized loss position fair value.

+ References

No definition available.

+ Details

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix:	mpb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Available for sale securities and held to maturity securities continuous unrealized loss position less than twelve months accumulated loss.

+ References

No definition available.

+ Details

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsAccumulatedLoss
Namespace Prefix:	mpb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Available for sale securities and held to maturity securities continuous unrealized loss position less than twelve months fair value.

+ References

No definition available.

+ Details

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Namespace Prefix:	mpb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Available for sale securities and held to maturity securities continuous unrealized loss position twelve months or longer accumulated loss.

+ References

No definition available.

+ Details

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerAccumulatedLoss
Namespace Prefix:	mpb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Available for sale securities and held to maturity securities continuous unrealized loss position twelve months or longer fair value.

+ References

No definition available.

+ Details

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix:	mpb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Available for sale securities and held to maturity securities in unrealized loss positions qualitative disclosure number of positions.

+ References

No definition available.

+ Details

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
Namespace Prefix:	mpb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Available for sale securities and held to maturity securities in unrealized loss positions qualitative disclosure number of positions greater than or equal to one year.

+ References

No definition available.

+ Details

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear
Namespace Prefix:	mpb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Available for sale securities and held to maturity securities in unrealized loss positions qualitative disclosure number of positions less than one year.

+ References

No definition available.

+ Details

Name:	mpb_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear
Namespace Prefix:	mpb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Held to maturity securities in unrealized loss positions qualitative disclosure number of positions greater than or equal to one year.

+ References

No definition available.

+ Details

Name:	mpb_HeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear
Namespace Prefix:	mpb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Held to maturity securities in unrealized loss positions qualitative disclosure number of positions less than one year.

+ References

No definition available.

+ Details

Name:	mpb_HeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear
Namespace Prefix:	mpb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for less than one year or normal operating cycle, if longer, for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

+ Details

Name:	us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of investment positions in available-for-sale investments that have been in a continuous unrealized loss position for greater than or equal to a year for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27337-111563

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27290-111563

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value of investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for less than 12 months.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27290-111563

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27337-111563

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for less than 12 months.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for 12 months or longer.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Disclosure regarding factors used to determine that the impairment of securities categorized as held-to-maturity where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the held-to-maturity investments determined to be temporarily impaired.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: