Debt - Additional Information (Detail) - Term Loan Facility [Member] - Berkshire Hathaway [Member] - USD ($)		6 Months Ended
Jul. 31, 2018	Jun. 30, 2019
Debt Instrument [Line Items]
Date of senior secured term loan agreement	Jul. 31, 2018
Principal amount outstanding	$ 2,000,000,000.0	$ 1,600,000,000
Line of credit, maturity date		Jul. 31, 2023
Prepayment annual fee	4,000,000.0
Minimum rental income to achieve from tenants on annual basis to access incremental funding facility	200,000,000
Minimum rental income to achieve from tenants for succeeding four consecutive fiscal quarters to access incremental funding facility	200,000,000
Minimum net worth required for loan documentation	$ 1,200,000,000
Default interest rate on overdue amounts excess of base interest rate	2.00%
Debt issuance costs	$ 2,100,000
Unamortized debt issuance costs		$ 1,700,000
Minimum [Member]
Debt Instrument [Line Items]
Fixed charge coverage ratio for each fiscal quarter till June 30, 2021	1.00%
Fixed charge coverage ratio for each fiscal quarter after June 30, 2021	1.20%
Unencumbered fixed charge coverage ratio for each fiscal quarter till June 30, 2021	1.05%
Unencumbered fixed charge coverage ratio to each fiscal quarter after June 30, 2021	1.30%
Maximum [Member]
Debt Instrument [Line Items]
Unencumbered fixed charge coverage ratio	60.00%
Maximum leverage ratio	65.00%
Initial Funding [Member]
Debt Instrument [Line Items]
Principal amount outstanding	$ 1,600,000,000
Debt instrument, base annual interest rate	7.00%
Incremental Funding Facility [Member]
Debt Instrument [Line Items]
Principal amount outstanding	$ 400,000,000
Debt instrument, base annual interest rate	1.00%

Date of senior secured term loan agreement.

No definition available.

Name:	srg_DateOfSeniorSecuredTermLoanAgreement
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Period Type:	duration

- Definition

Default interest rate on overdue amounts excess of base interest rate.

+ References

No definition available.

+ Details

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Namespace Prefix:	srg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed charge coverage ratio to each fiscal quarter after three years.

+ References

No definition available.

+ Details

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Namespace Prefix:	srg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Fixed charge coverage ratio to each fiscal quarter for next three years.

+ References

No definition available.

+ Details

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Namespace Prefix:	srg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility leverage ratio.

+ References

No definition available.

+ Details

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Namespace Prefix:	srg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum net worth required for loan documentation.

+ References

No definition available.

+ Details

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

- Definition

Minimum rental income to achieve from tenants for succeeding four consecutive fiscal quarters to access incremental funding facility.

+ References

No definition available.

+ Details

Name:	srg_MinimumRentalIncomeToAchieveFromTenantsForSucceedingFourConsecutiveFiscalQuartersToAccessIncrementalFundingFacility
Namespace Prefix:	srg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum rental income to achieve from tenants on annual basis to access incremental funding facility.

+ References

No definition available.

+ Details

Name:	srg_MinimumRentalIncomeToAchieveFromTenantsOnAnnualBasisToAccessIncrementalFundingFacility
Namespace Prefix:	srg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Prepayment annual fee.

+ References

No definition available.

+ Details

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

- Definition

Unencumbered fixed charge coverage ratio.

+ References

No definition available.

+ Details

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Namespace Prefix:	srg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Unencumbered fixed charge coverage ratio to each fiscal quarter for after three years.

+ References

No definition available.

+ Details

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Namespace Prefix:	srg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Unencumbered fixed charge coverage ratio to each fiscal quarter for next three years.

+ References

No definition available.

+ Details

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Namespace Prefix:	srg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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

Reference 2: 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 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(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

+ Details

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

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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