Name:	sqft_NumberOfLimitedLiabilityThatPurchaseAndLeasebackModelHomesFromDevelopersInWhichCompanyIsLimitedPartner
Namespace Prefix:	sqft_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of limited partnerships in which the company is the sole General Partner.

No definition available.

Name:	sqft_NumberOfLimitedPartnershipsInWhichCompanyIsSoleGeneralPartner
Namespace Prefix:	sqft_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of partnerships that purchase and lease back model homes from developers in which the company is a limited partner.

No definition available.

Name:	sqft_NumberOfPartnershipsThatPurchaseAndLeaseBackModelHomesFromDevelopersInWhichCompanyIsLimitedPartner
Namespace Prefix:	sqft_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Percentage of outside interest purchased.

No definition available.

Name:	sqft_PercentageOfOutsideInterestPurchased
Namespace Prefix:	sqft_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Area of a real estate property.

No definition available.

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

Description of key provisions in the operating or partnership agreement of the limited liability company or limited partnership, including liability, voting matters, distributions, and other provisions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

Name:	us-gaap_KeyProvisionsOfOperatingOrPartnershipAgreementDescription
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Data Type:	xbrli:stringItemType
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Period Type:	duration

The number of real estate properties owned as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

No definition available.

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

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.

No definition available.

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

Name:	dei_LegalEntityAxis=sqft_NetreitGardenGatewayLpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=sqft_OfficeIndustrialPropertiesAndMedicalBuildingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_RetailSiteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=sqft_RetailSitesAndMixedUsePropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=sqft_MixedUsePropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: