The number of properties consolidated and accounted for as step acquisition during the period.

No definition available.

Name:	spg_NumberOfOperatingPropertiesConsolidatedStepAcquisition
Namespace Prefix:	spg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of real estate properties in which additional interests were acquired during the period, resulting of the consolidation of the properties.

+ References

No definition available.

+ Details

Name:	spg_NumberOfRealEstatePropertiesAcquired
Namespace Prefix:	spg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the number of real estate properties that were disposed of during the period.

+ References

No definition available.

+ Details

Name:	spg_NumberOfRealEstatePropertiesDisposed
Namespace Prefix:	spg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

no definition

+ References

No definition available.

+ Details

Name:	spg_RealEstateAcquisitionsAbstract
Namespace Prefix:	spg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

no definition

+ References

No definition available.

+ Details

Name:	spg_RealEstateDispositionsAbstract
Namespace Prefix:	spg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

+ Details

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

- Definition

Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472

+ Details

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

- Definition

In a business combination achieved in stages, this element represents the amount of gain recognized by the entity as a result of remeasuring to fair value the equity interest in the acquiree it held before the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)(2)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

+ Details

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

- 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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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

- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2443-110228

+ Details

Name:	us-gaap_GainLossOnDispositionOfAssets1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the applicable amount of income taxes or benefit realized on the gain (loss) on sale of properties during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 974
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-15.(a)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=6875705&loc=d3e641549-123027

+ Details

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

- 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

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

+ Details

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

- Definition

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

+ Details

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

- Definition

The cash inflow from the sale of real estate held-for-investment and real estate joint ventures.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=spg_ResidentialAndRetailPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=spg_ShopsAtCrystalsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=spg_DesignerOutletPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=spg_EuropeanJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=spg_OutletCenterInOchtrupGermanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=spg_OutletCenterInItalyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=spg_OutletCenterInRoosendaalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_OtherIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=spg_IncomeAndOtherTaxesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=spg_RetailPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Real Estate Acquisitions and Dispositions (Details) € in Millions, $ in Millions					1 Months Ended		3 Months Ended
	Apr. 21, 2017 USD ($)	Jul. 25, 2016 EUR (€) property	Jul. 25, 2016 USD ($) property	Jan. 01, 2016 USD ($) property	Feb. 29, 2016 USD ($)	Jan. 31, 2016 USD ($) property	Sep. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2017 property	Dec. 31, 2016 property	Apr. 14, 2016
Residential and Retail Properties \| Disposed by Sales
Dispositions
Proceeds from sale or disposal of real estate assets						$ 72.4
The Shops at Crystals
Acquisitions
Ownership interests acquired (as a percent)											50.00%
Designer Outlet properties \| European Joint Venture
Acquisitions
Number of properties \| property				6					7	7
Non-cash gain on step acquisition				$ 12.1				$ 12.1
Number of consolidated properties under step acquisition \| property				2
Outlet Center In Ochtrup \| European Joint Venture
Acquisitions
Ownership interest (as a percent)					75.00%
Payments to acquire equity method investment					$ 38.3
Outlet Centers In Italy \| European Joint Venture
Acquisitions
Ownership interests acquired (as a percent)		33.00%	33.00%
Non-cash gain on step acquisition			$ 29.3				$ 29.3
Number of consolidated properties under step acquisition \| property		2	2
Cash purchase price for acquisition \| €		€ 145.5
Number of properties in which additional interest is acquired \| property		2	2
Outlet Center In Roosendaal \| European Joint Venture
Acquisitions
Ownership interests acquired (as a percent)	100.00%
Cash purchase price for acquisition	$ 69.8
Mortgage debt assumed	$ 40.1
Unconsolidated properties \| Residential properties \| Disposed by Sales
Dispositions
Number of properties disposed of during the period \| property						2
Unconsolidated properties \| Residential properties \| Disposed by Sales \| Other income.
Dispositions
Gain (loss) on disposition of interest in properties						$ 36.9
Unconsolidated properties \| Residential properties \| Disposed by Sales \| Income and other taxes
Dispositions
Gain from sale of properties, tax effect						$ 7.2
Consolidated properties \| Retail properties \| Disposed by Sales
Dispositions
Number of properties disposed of during the period \| property						1
Gain (loss) on disposition of interest in properties						$ 10.6