Note 4 - Loans and the Allowance for Credit Losses - Allocation of the Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Loans, Balance			$ 13,196
Charge-offs			(506)		$ (2,039)
Loans, Balance	$ 14,209		14,209		13,196
Loans, Net of Unfunded Commitments [Member]
Loans, Balance	13,319	$ 13,157	13,196	$ 12,867	12,867
Charge-offs	(194)	(330)	(506)	(1,010)
Recoveries	184	330	369	400
Provision for (recovery of) credit losses	900	925	1,150	1,825
Loans, Balance	14,209	14,082	14,209	14,082	13,196
Commercial Portfolio Segment [Member] \| Commercial Loans [Member]
Loans, Balance	1,286	1,311	1,265	1,134	1,134
Charge-offs	0	(22)	(165)	(65)	(302)
Recoveries	6	6	10	15
Provision for (recovery of) credit losses	105	131	287	342
Loans, Balance	1,397	1,426	1,397	1,426	1,265
Commercial Portfolio Segment [Member] \| Agricultural Loans [Member]
Loans, Balance	1,765	1,652	1,802	1,738	1,738
Charge-offs	(11)	0	(11)	0	0
Recoveries	0	0	0	0
Provision for (recovery of) credit losses	903	128	866	42
Loans, Balance	2,657	1,780	2,657	1,780	1,802
Commercial Portfolio Segment [Member] \| Real Estate Loan [Member]
Loans, Balance	7,635	6,917	7,459	6,678	6,678
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0
Provision for (recovery of) credit losses	107	664	283	903
Loans, Balance	7,742	7,581	7,742	7,581	7,459
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Loans, Balance	792	918	815	797	797
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0
Provision for (recovery of) credit losses	(98)	55	(121)	176
Loans, Balance	694	973	694	973	815
Residential Portfolio Segment [Member] \| Real Estate Loan [Member]
Loans, Balance	111	134	102	137	137
Charge-offs	0	0	0	0	0
Recoveries	1	1	2	2
Provision for (recovery of) credit losses	(2)	(14)	6	(18)
Loans, Balance	110	121	110	121	102
Residential Portfolio Segment [Member] \| Equity Lines of Credit [Member]
Loans, Balance	553	437	460	439	439
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0
Provision for (recovery of) credit losses	9	21	102	19
Loans, Balance	562	458	562	458	460
Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Loans, Balance	1,083	1,700	1,215	1,865	1,865
Charge-offs	(131)	(263)	(251)	(896)	(1,643)
Recoveries	172	319	349	376
Provision for (recovery of) credit losses	(169)	(102)	(358)	309
Loans, Balance	955	1,654	955	1,654	1,215
Consumer Portfolio Segment [Member] \| Other Loans [Member]
Loans, Balance	94	88	78	79	79
Charge-offs	(52)	(45)	(79)	(49)	(94)
Recoveries	5	4	8	7
Provision for (recovery of) credit losses	45	42	85	52
Loans, Balance	$ 92	$ 89	$ 92	$ 89	$ 78

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

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 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 2: 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

+ 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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-22

+ Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=plbc_EquityLinesOfCreditMember
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_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_AutomobileLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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