The amount of acquired loans that were individually evaluated for impairment.

No definition available.

Name:	pnbk_CertainLoansAcquiredIndividuallyEvaluatedForImpairment
Namespace Prefix:	pnbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Period of time between issuance and maturity of loan receivable, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	pnbk_LoansReceivableTerm
Namespace Prefix:	pnbk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time that a loan receivable takes to reset to the FHLB rate, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	pnbk_LoansReceivableTermToResetToFhlbRate
Namespace Prefix:	pnbk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of credit extension based on market value of collateral.

+ References

No definition available.

+ Details

Name:	pnbk_MaximumPercentageOfCreditExtensionBasedOnMarketValueOfCollateral
Namespace Prefix:	pnbk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum period for charged off of consumer installment loans.

+ References

No definition available.

+ Details

Name:	pnbk_MaximumPeriodForChargedOffOfConsumerInstallmentLoans
Namespace Prefix:	pnbk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum period of credit extension of construction loans.

+ References

No definition available.

+ Details

Name:	pnbk_MaximumPeriodOfCreditExtensionOfConstructionLoans
Namespace Prefix:	pnbk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of impaired loans held.

+ References

No definition available.

+ Details

Name:	pnbk_NumberOfImpairedLoans
Namespace Prefix:	pnbk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of maximum loan to value.

+ References

No definition available.

+ Details

Name:	pnbk_PercentageOfMaximumLoanToValue
Namespace Prefix:	pnbk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents performance period under loan terms.

+ References

No definition available.

+ Details

Name:	pnbk_PerformancePeriodUnderLoanTerms
Namespace Prefix:	pnbk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period for charged off of close end credits.

+ References

No definition available.

+ Details

Name:	pnbk_PeriodForChargedOffOfCloseendCredits
Namespace Prefix:	pnbk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period for charged off of open end credits

+ References

No definition available.

+ Details

Name:	pnbk_PeriodForChargedOffOfOpenendCredits
Namespace Prefix:	pnbk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

+ Details

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

- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

+ Details

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

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

+ Details

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

- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

+ Details

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

- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

+ Details

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

- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

+ Details

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

- Definition

Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554

+ Details

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

- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

+ Details

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

- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans held for sale. 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 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(a))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

The cash outflow for the purchase of loan receivable arising from the financing of goods and services.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

+ Details

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

- Definition

Disclosure of the unamortized amount of the premium on the note or receivable which is added to the face amount of the receivable or loan. The discount or premium is defined as the difference between the present value and the face amount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

+ Details

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

- Definition

Threshold period past due for financing receivable to write off as uncollectible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_ThresholdPeriodPastDueForWriteoffOfFinancingReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=pnbk_NonaccrualLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=pnbk_ConstructionPortfolioSegmentMember
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_FinancingReceivablePortfolioSegmentAxis=pnbk_ConstructionToPermanentPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
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:

Note 5 - Loans Receivable and Allowance for Loan Losses (Details Textual)	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	May 10, 2018 USD ($)	Dec. 31, 2017 USD ($)
Loans Receivable, Net, Total		$ 750,804,000		$ 750,804,000			$ 713,350,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net						$ 2,400,000
Payments to Acquire Loans Receivable					$ 73,022,000
Maximum Period of Credit Extension of Construction Loans				1 year 180 days
Loans Receivable, Term to Reset to FHLB Rate				5 years
Certain Loans Acquired, Individually Evaluated for Impairment		21,900,000		$ 21,900,000
Period for Charged Off of Open-End Credits				180 days
Period for Charged Off of Close-End Credits				120 days
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans		103,000	$ 22,000	$ 176,000	43,000
Threshold Period Past Due for Write-off of Financing Receivable				90 days
Maximum Period for Charged Off of Consumer Installment Loans				180 days
Performance Period Under Loan Terms				180 days
Financing Receivable, Modifications, Recorded Investment		$ 2,900,000		$ 2,900,000			3,000,000
Financing Receivable, Modifications, Number of Contracts		0	0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts		0	0
Loans and Leases Receivable, Impaired, Commitment to Lend		$ 0		0			0
Impaired Financing Receivable, Recorded Investment, Total		9,400,000		9,400,000			6,800,000
Impaired Financing Receivable, Related Allowance		$ 45,000		$ 45,000			$ 253,000
Number of Impaired Loans		14		14			12
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses						0
Non-Accrual Loans [Member]
Impaired Financing Receivable, Interest Income, Cash Basis Method, Total		$ 0	$ 0	$ 0	$ 0
Acquired Loans [Member]
Loans Receivable, Net, Total		$ 21,908,000		$ 21,908,000		21,600,000
Acquired Loans [Member] \| Financial Asset Acquired and No Credit Deterioration [Member]
Loans Receivable, Net, Total						19,200,000
Commercial Real Estate Portfolio Segment [Member]
Maximum Percentage of Credit Extension Based on Market Value of Collateral				75.00%
Multi-family Real Estate [Member]
Maximum Percentage of Credit Extension Based on Market Value of Collateral				80.00%
Construction Portfolio Segment [Member]
Percentage of Maximum Loan to Value				75.00%
Residential Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net						400,000
Payments to Acquire Loans Receivable	$ 73,000,000			$ 0
Receivable with Imputed Interest, Premium	$ 985,000
Construction to Permanent Portfolio Segment [Member] \| Minimum [Member]
Loans Receivable, Term				20 years
Construction to Permanent Portfolio Segment [Member] \| Maximum [Member]
Loans Receivable, Term				25 years
Commercial Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net						$ 2,000,000