Concentration risk annualized base rent percentage.

No definition available.

Name:	srg_ConcentrationRiskAnnualizedBaseRentPercentage
Namespace Prefix:	srg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Distribution of taxable income to qualify as REIT.

+ References

No definition available.

+ Details

Name:	srg_DistributionOfTaxableIncomeToQualifyAsReit
Namespace Prefix:	srg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Impairment of unconsolidated joint venture.

+ References

No definition available.

+ Details

Name:	srg_ImpairmentOfUnconsolidatedJointVenture
Namespace Prefix:	srg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

(Increase) decrease in rental revenue.

+ References

No definition available.

+ Details

Name:	srg_IncreaseDecreaseInRentalRevenue
Namespace Prefix:	srg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of consolidated properties acquired.

+ References

No definition available.

+ Details

Name:	srg_NumberOfConsolidatedPropertiesAcquired
Namespace Prefix:	srg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of entities acquired.

+ References

No definition available.

+ Details

Name:	srg_NumberOfEntitiesAcquired
Namespace Prefix:	srg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of tenant.

+ References

No definition available.

+ Details

Name:	srg_NumberOfTenant
Namespace Prefix:	srg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of variable interest entity consolidated.

+ References

No definition available.

+ Details

Name:	srg_NumberOfVariableInterestEntityConsolidated
Namespace Prefix:	srg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of revenue earned from unconsolidated joint ventures.

+ References

No definition available.

+ Details

Name:	srg_PercentageOfRevenueEarnedFromUnconsolidatedJointVentures
Namespace Prefix:	srg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Summary of Significant Accounting Policies [Line Items]

+ References

No definition available.

+ Details

Name:	srg_SummaryOfSignificantAccountingPoliciesLineItems
Namespace Prefix:	srg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of assets held-for-sale that are not part of a disposal group.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 15
-Paragraph 4
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=123398962&loc=d3e400-110220

+ Details

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

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644

Reference 2: 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(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The charge against earnings in the period to reduce the carrying amount of real property to fair value.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-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_ImpairmentOfRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8672-108599

+ Details

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

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

For banks, amount of all liabilities for which a financial institution is required to include in its calculation of net investment in real estate assets held for development or sale.

+ References

No definition available.

+ Details

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

- Definition

Description of method used to recognize revenue for performance obligation that is satisfied over time. Includes, but not is limited to, output or input method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130563-203045

+ Details

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

- Definition

Difference between actual rental income due and rental income recognized on a straight-line basis.

+ 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
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

+ Details

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

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=us-gaap_ManagementServiceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=srg_AllowanceForDeferralAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=srg_OperatingPartnershipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2022 USD ($) Tenant Entity Property JointVenture State Segment shares	Mar. 31, 2021 USD ($) shares	Dec. 31, 2021 Property
Summary Of Significant Accounting Policies [Line Items]
Number of VIEs consolidated \| Entity	2
Number of reportable segments \| Segment	1
Number of properties classified \| Property	11		0
Impairment of real estate assets	$ 991,000	$ 1,700,000
Real estate held for sale, assets	92,078,000
Real estate held for sale, liabilities	0
Impairment loss	0	0
Increase to rental income	200,000	200,000
Reversal of straight line rent	$ 100,000	$ 1,000,000.0
Revenue performance obligation satisfied over time method used description	Management determined that property and asset management and construction and development management services each represent a series of stand-ready performance obligations satisfied over time with each day of service being a distinct performance obligation.
Number of tenant \| Tenant	1
Annualized based rent	13.20%
Number of consolidated properties acquired \| Property	136
Number of entities acquired \| JointVenture	25
Number of states in properties located \| State	38
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Distribution of taxable income to qualify as REIT, percent	90.00%
Class C Common Shares [Member]
Summary Of Significant Accounting Policies [Line Items]
Common shares, outstanding \| shares	0
Class B Common Shares [Member]
Summary Of Significant Accounting Policies [Line Items]
Common shares, outstanding \| shares	0	0
Management and Other Fee Income [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue earned from unconsolidated joint ventures	100.00%
Allowance for Deferral Agreements [Member]
Summary Of Significant Accounting Policies [Line Items]
Increase to rental income	$ 100,000	$ 100,000
Operating Partnership [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of operating partnership interest held by parent	77.90%