Number of real estate properties damaged during the period.

No definition available.

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

- Definition

Amount of aggregate cash inflow for proceeds from settlement of insurance claim.

+ References

No definition available.

+ Details

Name:	spg_ProceedsFromInsuranceSettlement
Namespace Prefix:	spg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

- Definition

Amount of cash inflow for proceeds from settlement of insurance claim, classified as investing activities. Excludes insurance settlement classified as operating activities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21B
-URI http://asc.fasb.org/extlink&oid=121586364&loc=SL94080549-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

+ Details

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

- Definition

Amount of cash inflow for proceeds from settlement of insurance claim, classified as operating activities. Excludes insurance settlement classified as investing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 16
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3337-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21B
-URI http://asc.fasb.org/extlink&oid=121586364&loc=SL94080549-108585

+ Details

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

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_LossFromCatastrophesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_PR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=us-gaap_WhollyOwnedPropertiesMember
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:

Commitments and Contingencies - Hurricane Impacts (Details) $ in Thousands	3 Months Ended			6 Months Ended		30 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Sep. 30, 2017 property	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2020 USD ($)
Hurricane Impact
Insurance proceeds for property restoration				$ 1,058	$ 2,938
Loss from Catastrophes \| PUERTO RICO \| Wholly owned properties
Hurricane Impact
Number of properties significantly damaged \| property			2
Total insurance proceeds received						$ 77,600
Insurance proceeds for property restoration						$ 46,500
Loss from Catastrophes \| PUERTO RICO \| Wholly owned properties \| Other income
Hurricane Impact
Insurance proceeds for business interruption	$ 1,600	$ 3,200		$ 2,700	$ 7,600