No definition available.

Name:	pstl_DebtDetailsLineItems
Namespace Prefix:	pstl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Annual Principal Payments, Number

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentAnnualPrincipalPaymentsNumber
Namespace Prefix:	pstl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Basis Spread on Variable Rate, Increase (Decrease)

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentBasisSpreadOnVariableRateIncreaseDecrease
Namespace Prefix:	pstl_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Fixed Interest Period

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentFixedInterestPeriod
Namespace Prefix:	pstl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Interest Rate, Fixed Rate Period

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentInterestRateFixedRatePeriod
Namespace Prefix:	pstl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Number Of Properties Collateralized Under Loan

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentNumberOfPropertiesCollateralizedUnderLoan
Namespace Prefix:	pstl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument, Remaining Discount Amortization Period

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentRemainingDiscountAmortizationPeriod
Namespace Prefix:	pstl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Remaining Percentage Collateralized Under Loan

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentRemainingPercentageCollateralizedUnderLoan
Namespace Prefix:	pstl_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Variable Rate Adjustment

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentVariableRateAdjustment
Namespace Prefix:	pstl_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Variable Rate Floor

+ References

No definition available.

+ Details

Name:	pstl_DebtInstrumentVariableRateFloor
Namespace Prefix:	pstl_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Facility, Accordion Feature, Increase Limit

+ References

No definition available.

+ Details

Name:	pstl_LineOfCreditFacilityAccordionFeatureIncreaseLimit
Namespace Prefix:	pstl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line Of Credit Facility, Extension Period

+ References

No definition available.

+ Details

Name:	pstl_LineOfCreditFacilityExtensionPeriod
Namespace Prefix:	pstl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line Of Credit Facility, Number Of Options To Extend

+ References

No definition available.

+ Details

Name:	pstl_LineOfCreditFacilityNumberOfOptionsToExtend
Namespace Prefix:	pstl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Line Of Credit Facility, Unused Capacity, Commitment Fee Percentage, Threshold

+ References

No definition available.

+ Details

Name:	pstl_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentageThreshold
Namespace Prefix:	pstl_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average maturity date for secured borrowing.

+ References

No definition available.

+ Details

Name:	pstl_WeightedAverageMaturityDateForSecuredBorrowingTerm
Namespace Prefix:	pstl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of assets pledged to secure a debt instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of the required periodic payments including both interest and principal payments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823

+ Details

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

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of the fee for available but unused credit capacity under the credit facility.

+ References

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LoansPayableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pstl_A2021CreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	pstl_LineOfCreditCommitmentFeeThresholdAxis=pstl_CommitmentFeeThresholdOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	pstl_LineOfCreditCommitmentFeeThresholdAxis=pstl_CommitmentFeeThresholdTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
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_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pstl_A2019And2021RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pstl_VisionBankMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_UsTreasuryUstInterestRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pstl_FirstOklahomaBankLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_PrimeRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pstl_VisionBankTwoThousandEighteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pstl_SellerFinancingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pstl_FirstAmendedCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Narrative (Details) $ in Thousands					3 Months Ended			9 Months Ended
Debt - Narrative (Details) $ in Thousands	May 11, 2022 USD ($)	Sep. 30, 2021	Aug. 09, 2021 USD ($) option	Jul. 23, 2021	Sep. 30, 2022 USD ($) payment	Mar. 31, 2022	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) property payment	Sep. 30, 2021 USD ($)
Debt (Details) [Line Items]
Weighted average maturity date for secured borrowing						6 years 6 months		5 years 4 months 24 days
Loan
Debt (Details) [Line Items]
Interest rate					2.80%			2.80%
Fixed interest period								5 years
Remaining discount amortization period								30 years
2021 Credit Facility \| Revolving credit facility \| Line of credit
Debt (Details) [Line Items]
Maximum borrowing facility			$ 150,000
Accordion feature			$ 150,000
Number of options to extend (in options) \| option			2
Extension period			6 months
2021 Credit Facility \| Revolving credit facility \| Line of credit \| Commitment fee threshold one
Debt (Details) [Line Items]
Capacity used (as a percentage)			0.50
Unused facility fee (as a percentage)			0.20%
2021 Credit Facility \| Revolving credit facility \| Line of credit \| Commitment fee threshold two
Debt (Details) [Line Items]
Capacity used (as a percentage)			0.50
Unused facility fee (as a percentage)			0.15%
2021 Credit Facility \| Unsecured debt \| Line of credit
Debt (Details) [Line Items]
Total Principal			$ 50,000
Accordion feature			$ 50,000
2021 Credit Facility \| Base Rate \| Revolving credit facility \| Line of credit \| Minimum
Debt (Details) [Line Items]
Basis spread on variable rate	0.50%
2021 Credit Facility \| Base Rate \| Revolving credit facility \| Line of credit \| Maximum
Debt (Details) [Line Items]
Basis spread on variable rate	1.00%
2021 Credit Facility \| Base Rate \| Unsecured debt \| Line of credit \| Minimum
Debt (Details) [Line Items]
Basis spread on variable rate	0.45%
2021 Credit Facility \| Base Rate \| Unsecured debt \| Line of credit \| Maximum
Debt (Details) [Line Items]
Basis spread on variable rate	0.95%
2021 Credit Facility \| LIBOR \| Unsecured debt \| Line of credit
Debt (Details) [Line Items]
Basis spread on variable rate								1.45%
2021 Credit Facility \| LIBOR \| Unsecured debt \| Line of credit \| Minimum
Debt (Details) [Line Items]
Basis spread on variable rate	1.45%
2021 Credit Facility \| LIBOR \| Unsecured debt \| Line of credit \| Maximum
Debt (Details) [Line Items]
Basis spread on variable rate	1.95%
2021 Credit Facility \| SOFR \| Revolving credit facility \| Line of credit
Debt (Details) [Line Items]
Decrease in margin	(0.0002)
2021 Credit Facility \| SOFR \| Revolving credit facility \| Line of credit \| Minimum
Debt (Details) [Line Items]
Basis spread on variable rate	1.50%
2021 Credit Facility \| SOFR \| Revolving credit facility \| Line of credit \| Maximum
Debt (Details) [Line Items]
Basis spread on variable rate	2.00%
2021 Credit Facility \| SOFR \| Unsecured debt \| Line of credit
Debt (Details) [Line Items]
Variable rate adjustment	0.0010
Variable rate floor	0
2019 and 2021 Revolving Credit Facility \| Revolving credit facility \| Line of credit
Debt (Details) [Line Items]
Unused facility fee					$ 60		$ 50	$ 200	$ 200
Vision Bank \| Loan
Debt (Details) [Line Items]
Interest rate					3.69%			3.69%
Percentage collateralized under loan					50.00%			50.00%
Fixed interest rate period								5 years
Number of properties collateralized under loan (in properties) \| property								5
Vision Bank \| Loan \| Minimum
Debt (Details) [Line Items]
Minimum annual rate					2.75%			2.75%
Vision Bank \| US Treasury (UST) Interest Rate \| Loan
Debt (Details) [Line Items]
Basis spread on variable rate		2.75%
First Oklahoma Bank loan
Debt (Details) [Line Items]
Interest rate				3.625%
Fixed interest rate period				5 years
First Oklahoma Bank loan \| Loan
Debt (Details) [Line Items]
Interest rate					3.625%			3.625%
Number of properties collateralized under loan (in properties) \| property								4
First Oklahoma Bank loan \| Prime Rate \| Minimum
Debt (Details) [Line Items]
Interest rate				3.625%
Vision Bank – 2018
Debt (Details) [Line Items]
Fixed interest rate period								5 years
Minimum annual rate					2.75%			2.75%
Vision Bank – 2018 \| Loan
Debt (Details) [Line Items]
Interest rate					3.69%			3.69%
Number of properties collateralized under loan (in properties) \| property								1
Vision Bank – 2018 \| US Treasury (UST) Interest Rate
Debt (Details) [Line Items]
Basis spread on variable rate		2.75%
Seller Financing \| Loan
Debt (Details) [Line Items]
Interest rate					6.00%			6.00%
Collateral amount					$ 400			$ 400
Number of annual principal payments (in payments) \| payment					5			5
Periodic payment								$ 100
First Amended Credit Facility \| Unsecured debt \| Line of credit
Debt (Details) [Line Items]
Maximum borrowing facility	$ 75,000
Accordion feature	$ 75,000