Loans Receivable and Allowance for Credit Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Allowance for Loan and Lease Losses [Roll Forward]
Balance	$ 24,098	$ 9,929	$ 10,310	$ 9,905
Charge-offs	(3,548)	(366)	(8,016)	(651)
Recoveries	318	189	778	223
Provisions (credits)	4,800	200	9,595	475
Balance	25,668	9,952	25,668	9,952
Impact of ASC 326 Adoption
Allowance for Loan and Lease Losses [Roll Forward]
Balance			13,001
Unfunded Loan Commitment
Allowance for Loan and Lease Losses [Roll Forward]
Provisions (credits)	112		1,400
Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Balance	10,039	4,980	6,966	5,063
Charge-offs	0	0	0	0
Recoveries	0	154	0	154
Provisions (credits)	3,321	1,653	4,768	1,570
Balance	13,360	6,787	13,360	6,787
Commercial Real Estate \| Impact of ASC 326 Adoption
Allowance for Loan and Lease Losses [Roll Forward]
Balance			1,626
Residential Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Balance	1,027	1,395	665	1,700
Charge-offs	(113)	0	(113)	0
Recoveries	3	3	14	4
Provisions (credits)	171	(930)	333	(1,236)
Balance	1,088	468	1,088	468
Residential Real Estate \| Impact of ASC 326 Adoption
Allowance for Loan and Lease Losses [Roll Forward]
Balance			189
Commercial and Industrial
Allowance for Loan and Lease Losses [Roll Forward]
Balance	1,673	2,316	1,403	2,532
Charge-offs	(423)	0	(429)	(70)
Recoveries	9	12	25	38
Provisions (credits)	149	(490)	190	(662)
Balance	1,408	1,838	1,408	1,838
Commercial and Industrial \| Impact of ASC 326 Adoption
Allowance for Loan and Lease Losses [Roll Forward]
Balance			219
Consumer and Other
Allowance for Loan and Lease Losses [Roll Forward]
Balance	11,275	1,063	1,207	253
Charge-offs	(3,012)	(366)	(7,324)	(513)
Recoveries	306	20	739	27
Provisions (credits)	1,127	22	4,097	972
Balance	9,696	739	9,696	739
Consumer and Other \| Impact of ASC 326 Adoption
Allowance for Loan and Lease Losses [Roll Forward]
Balance			10,977
Construction
Allowance for Loan and Lease Losses [Roll Forward]
Balance	33	58	24	78
Charge-offs	0	0	(150)	(68)
Recoveries	0	0	0	0
Provisions (credits)	(31)	(20)	132	28
Balance	2	38	2	38
Construction \| Impact of ASC 326 Adoption
Allowance for Loan and Lease Losses [Roll Forward]
Balance			(4)
Construction to Permanent - CRE
Allowance for Loan and Lease Losses [Roll Forward]
Balance	51	15	10	41
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provisions (credits)	63	(10)	75	(36)
Balance	114	5	114	5
Construction to Permanent - CRE \| Impact of ASC 326 Adoption
Allowance for Loan and Lease Losses [Roll Forward]
Balance			29
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Balance	0	102	35	238
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provisions (credits)	0	(25)	0	(161)
Balance	$ 0	$ 77	0	$ 77
Unallocated \| Impact of ASC 326 Adoption
Allowance for Loan and Lease Losses [Roll Forward]
Balance			$ (35)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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

- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-1

+ Details

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

- Definition

Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

+ Details

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

- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

+ Details

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

- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

+ Details

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

- Details

Name:	srt_CumulativeEffectPeriodOfAdoptionAxis=srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=pnbk_ConsumerAndOtherPortfolioSegmentMember
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=pnbk_ConstructionToPermanentPortfolioSegmentMember
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: