Loans and Allowance for Loan and Lease Losses (Allowance And Recorded Investment In Financing Receivables) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance	$ 8,189	$ 7,713	$ 7,606	$ 7,183
Charge-offs	(67)	(239)	(418)	(315)
Recoveries	7	28	816	409
Provisions	100		225	225
Allowance for Loan Losses, Ending Balance	8,229	7,502	8,229	7,502
Allowance for loan losses: Ending balance: individually evaluated for impairment	770	691	770	691	$ 529
Allowance for loan losses: Ending balance: collectively evaluated for impairment	7,459	6,811	7,459	6,811	7,077
Loans receivables, Ending Balance	1,567,286	877,386	1,567,286	877,386	910,404
Loans receivables: Ending balance: individually evaluated for impairment	8,641	8,212	8,641	8,212	10,788
Loans Receivable: Ending balance: collectively evaluated for impairment	1,555,893	868,290	1,555,893	868,290	898,755
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivables, Ending Balance	2,752	884	2,752	884	861
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance	420	404	423	379
Charge-offs		(20)	(167)	(20)
Recoveries				5
Provisions	16	53	180	73
Allowance for Loan Losses, Ending Balance	436	437	436	437
Allowance for loan losses: Ending balance: collectively evaluated for impairment	436	437	436	437	423
Loans receivables, Ending Balance	73,849	40,350	73,849	40,350	41,893
Loans receivables: Ending balance: individually evaluated for impairment	25	261	25	261	260
Loans Receivable: Ending balance: collectively evaluated for impairment	73,820	40,089	73,820	40,089	41,633
Home Equity [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivables, Ending Balance	4		4
Commercial Portfolio [Member] \| Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance	2,120	1,628	1,795	1,580
Charge-offs	(12)		(142)	(12)
Recoveries		5	1	11
Provisions	232	166	686	220
Allowance for Loan Losses, Ending Balance	2,340	1,799	2,340	1,799
Allowance for loan losses: Ending balance: individually evaluated for impairment	489	150	489	150	136
Allowance for loan losses: Ending balance: collectively evaluated for impairment	1,851	1,649	1,851	1,649	1,659
Loans receivables, Ending Balance	269,150	182,857	269,150	182,857	188,033
Loans receivables: Ending balance: individually evaluated for impairment	4,527	4,460	4,527	4,460	4,434
Loans Receivable: Ending balance: collectively evaluated for impairment	264,595	178,397	264,595	178,397	183,599
Commercial Portfolio [Member] \| Commercial and Industrial [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivables, Ending Balance	28		28
Commercial Portfolio [Member] \| Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance	4,723	4,981	4,435	4,323
Charge-offs	(34)	(207)	(34)	(237)
Recoveries	2	22	807	383
Provisions	130	(326)	(387)	1
Allowance for Loan Losses, Ending Balance	4,821	4,470	4,821	4,470
Allowance for loan losses: Ending balance: individually evaluated for impairment	243	375	243	375	293
Allowance for loan losses: Ending balance: collectively evaluated for impairment	4,578	4,095	4,578	4,095	4,142
Loans receivables, Ending Balance	812,822	490,603	812,822	490,603	515,012
Loans receivables: Ending balance: individually evaluated for impairment	2,890	2,148	2,890	2,148	4,847
Loans Receivable: Ending balance: collectively evaluated for impairment	808,476	487,886	808,476	487,886	509,610
Commercial Portfolio [Member] \| Commercial Real Estate [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivables, Ending Balance	1,456	569	1,456	569	555
Commercial Portfolio [Member] \| Commercial Real Estate - Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance	146	140	178	144
Charge-offs			(40)
Provisions	(12)	36	(4)	32
Allowance for Loan Losses, Ending Balance	134	176	134	176
Allowance for loan losses: Ending balance: individually evaluated for impairment	38	100	38	100	100
Allowance for loan losses: Ending balance: collectively evaluated for impairment	96	76	96	76	78
Loans receivables, Ending Balance	145,368	58,074	145,368	58,074	62,336
Loans receivables: Ending balance: individually evaluated for impairment	367	487	367	487	487
Loans Receivable: Ending balance: collectively evaluated for impairment	145,001	57,587	145,001	57,587	61,849
Commercial Portfolio [Member] \| Lease Financing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance		1		1
Provisions		(1)		(1)
Loans receivables, Ending Balance	132	259	132	259	229
Loans Receivable: Ending balance: collectively evaluated for impairment	132	259	132	259	229
Consumer Portfolio [Member] \| Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance	4	4	3	3
Charge-offs	(11)	(5)	(21)	(21)
Recoveries	5	1	8	6
Provisions	7	5	15	17
Allowance for Loan Losses, Ending Balance	5	5	5	5
Allowance for loan losses: Ending balance: collectively evaluated for impairment	5	5	5	5	3
Loans receivables, Ending Balance	10,579	4,170	10,579	4,170	3,868
Loans Receivable: Ending balance: collectively evaluated for impairment	10,579	4,170	10,579	4,170	3,868
Residential Portfolio [Member] \| Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance	441	539	428	541
Charge-offs	(10)	(7)	(14)	(25)
Recoveries				4
Provisions	38	7	55	19
Allowance for Loan Losses, Ending Balance	469	539	469	539
Allowance for loan losses: Ending balance: individually evaluated for impairment		66		66
Allowance for loan losses: Ending balance: collectively evaluated for impairment	469	473	469	473	428
Loans receivables, Ending Balance	255,386	101,073	255,386	101,073	99,033
Loans receivables: Ending balance: individually evaluated for impairment	832	856	832	856	760
Loans Receivable: Ending balance: collectively evaluated for impairment	253,290	99,902	253,290	99,902	97,967
Residential Portfolio [Member] \| Financial Asset Acquired with Credit Deterioration [Member] \| Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivables, Ending Balance	1,264	315	1,264	315	306
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses, Beginning Balance	335	16	344	212
Provisions	(311)	60	(320)	(136)
Allowance for Loan Losses, Ending Balance	24	76	24	76
Allowance for loan losses: Ending balance: collectively evaluated for impairment	$ 24	$ 76	$ 24	$ 76	$ 344

A valuation allowance for financing receivables that are expected to be uncollectible.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(4)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

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

- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

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

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

+ Details

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

- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_CreditLossStatusAxis=us-gaap_FinancialAssetAcquiredWithCreditDeteriorationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mpb_CommercialAndIndustrialLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_RealEstateLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mpb_FinancingLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_UnallocatedFinancingReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: