The number of properties owned via an International joint venture.

No definition available.

Name:	spg_InternationalJointVentureProperties
Namespace Prefix:	spg_
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:	spg_JointVenturePropertiesManagedByOthers
Namespace Prefix:	spg_
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:	spg_JointVenturePropertiesManagedNumber
Namespace Prefix:	spg_
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:	spg_JointVenturePropertiesNumber
Namespace Prefix:	spg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

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

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

Name:	us-gaap_RangeAxis=us-gaap_WeightedAverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

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

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

Basis of Presentation (Details)	Mar. 31, 2015 property	Dec. 31, 2014	Mar. 31, 2014
Real Estate Properties
Total number of joint venture properties	82spg_JointVenturePropertiesNumber
Number of joint venture properties managed by the entity	58spg_JointVenturePropertiesManagedNumber
Number of International joint venture properties	19spg_InternationalJointVentureProperties
Number of joint venture properties managed by others	24
Ownership interest:
Ownership percentage in the Operating Partnership	85.50%	85.50%
McArthurGlen Group
Real Estate Properties
Number of properties	5
Weighted average
Ownership interest:
Ownership percentage in the Operating Partnership	85.50%		85.60%
Wholly owned properties
Real Estate Properties
Number of properties	135
Partially owned properties
Real Estate Properties
Number of properties	13