The number of properties owned via an International joint venture.

No definition available.

Name:	simon_InternationalJointVentureProperties
Namespace Prefix:	simon_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of properties owned via a joint venture in which daily operations are managed by groups other than the entity.

No definition available.

Name:	simon_JointVenturePropertiesManagedByOthers
Namespace Prefix:	simon_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of properties owned via a joint venture in which daily operations are managed by the entity.

No definition available.

Name:	simon_JointVenturePropertiesManagedNumber
Namespace Prefix:	simon_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of properties owned via a joint venture and accounted for using the equity method of accounting.

No definition available.

Name:	simon_JointVenturePropertiesNumber
Namespace Prefix:	simon_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

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

No definition available.

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

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

No definition available.

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

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

Basis of Presentation (Details)	Sep. 30, 2013 property	Sep. 30, 2013 Simon Property Group, Inc.	Dec. 31, 2012 Simon Property Group, Inc.	Sep. 30, 2013 Simon Property Group, Inc. Weighted average	Sep. 30, 2012 Simon Property Group, Inc. Weighted average	Sep. 30, 2013 Wholly owned properties property	Sep. 30, 2013 Partially owned properties property
Basis of Presentation and Consolidation
Number of properties included in consolidation						220	18
Total number of joint venture properties	89
Number of joint venture properties managed by the entity	71
Number of International joint venture properties	15
Number of joint venture properties managed by others	18
Ownership percentage in the Operating Partnership		85.60%	85.60%	85.60%	83.30%