Assets Held By Unconsolidated Affiliates

No definition available.

Name:	sret_AssetsHeldByUnconsolidatedAffiliates
Namespace Prefix:	sret_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cash Contributions To Limited Liability Company

+ References

No definition available.

+ Details

Name:	sret_CashContributionsToLimitedLiabilityCompany
Namespace Prefix:	sret_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The approximate development project budget.

+ References

No definition available.

+ Details

Name:	sret_DevelopmentProjectBudget
Namespace Prefix:	sret_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Mortgage Notes Held By Unconsolidated Affiliates

+ References

No definition available.

+ Details

Name:	sret_MortgageNotesHeldByUnconsolidatedAffiliates
Namespace Prefix:	sret_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of real estate properties classified as held for sale as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	sret_NumberOfRealEstatePropertiesClassifiedAsHeldForSale
Namespace Prefix:	sret_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage Of Interest

+ References

No definition available.

+ Details

Name:	sret_PercentageOfInterest
Namespace Prefix:	sret_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of interest acquired

+ References

No definition available.

+ Details

Name:	sret_PercentageOfInterestAcquired
Namespace Prefix:	sret_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Residential Multi Tenant Apartment Complex Units

+ References

No definition available.

+ Details

Name:	sret_ResidentialMultiTenantApartmentComplexUnits
Namespace Prefix:	sret_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Area of a real estate property.

+ References

No definition available.

+ Details

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

- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ 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(11))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(12))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Impairment losses measured as the amount by which the carrying amount of the business or real estate partnerships exceeds the fair value of the business or partnership.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2921-110230

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: 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(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=sret_SingleAssetLimitedLiabilityCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=sret_SeMapleGroveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=sret_GrandForksMarketplaceRetailCenterMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=sret_TenantInCommonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=sret_SESavageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_RealEstatePropertiesAxis=sret_GlenPondDevelopmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=sret_GoldmarkOfficeParkDevelopmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Principal Activity and Significant Accounting Policies - Held for Sale and Unconsolidated Affiliates (Details) $ in Thousands		12 Months Ended
	May 01, 2017 item	Dec. 31, 2019 USD ($) ft² property item	Dec. 31, 2018 USD ($) property	Dec. 31, 2017 USD ($)
Significant Accounting Policies
Number of real estate properties classified as held for sale \| property		0	0
Impairment losses related to the unconsolidated affiliates		$ 0	$ 0	$ 0
Total assets held by unconsolidated affiliates		31,261	22,954
Mortgage notes held by unconsolidated affiliates		16,690	17,091
Assets		$ 699,686	714,467
Single Asset Limited Liability Company - owns apartment complex, Bismarck, North Dakota
Significant Accounting Policies
Residential Multi Tenant Apartment Complex Units \| item	144	144
Percentage of interest acquired	59.74%
SE Maple Grove
Significant Accounting Policies
Assets		$ 3,455
Operating Partnership \| Single Asset Limited Liability Company - owns apartment complex, Bismarck, North Dakota
Significant Accounting Policies
Investment in unconsolidated affiliates		40.26%
Operating Partnership \| Grand Forks Marketplace Retail Center
Significant Accounting Policies
Investment in unconsolidated affiliates		50.00%
Percentage of interest		100.00%
Area of commercial property \| ft²		183,000
Operating Partnership \| Tenant in common - Office building, Fargo, North Dakota
Significant Accounting Policies
Investment in unconsolidated affiliates		66.67%
Area of commercial property \| ft²		75,000
Operating Partnership \| SE Savage
Significant Accounting Policies
Number of units \| property		190
Investment in unconsolidated affiliates		60.00%
Cash contribution		$ 3,277
Operating Partnership \| SE Maple Grove
Significant Accounting Policies
Number of units \| property		160
Investment in unconsolidated affiliates		60.00%
Cash contribution		$ 2,073
SE Savage
Significant Accounting Policies
Assets		5,464
Mortgages \| Grand Forks Marketplace Retail Center
Significant Accounting Policies
Mortgage carrying amount		10,264	10,483
Mortgages \| Tenant in common - Office building, Fargo, North Dakota
Significant Accounting Policies
Mortgage carrying amount		6,426	$ 6,608
Mortgages \| SE Maple Grove
Significant Accounting Policies
Mortgage carrying amount		0
Mortgages \| SE Savage
Significant Accounting Policies
Mortgage carrying amount		$ 0
Glen Pond Development
Significant Accounting Policies
Number of units \| item		114
Development project budget		$ 15,598
Goldmark Office Park 1715 Building
Significant Accounting Policies
Development project budget		$ 2,000