In a business combination achieved in stages, this element represents the amount of gain or loss recognized by the entity as a result of re-measuring to fair value the equity interest in the acquiree it held before the business combination. Also includes the difference between the carrying value and the sales price for consolidated investment property and equity method investments.

No definition available.

Real Estate Acquisitions and Dispositions (Details) $ in Thousands									1 Months Ended	3 Months Ended				6 Months Ended	12 Months Ended
	Jul. 25, 2016 USD ($) property	Jan. 01, 2016 USD ($) property	Jan. 15, 2015 USD ($)	Sep. 26, 2014 USD ($)	Apr. 16, 2014 USD ($) property	Apr. 10, 2014	Jan. 30, 2014 USD ($) a shares	Jan. 10, 2014 USD ($) property item	Feb. 29, 2016 USD ($)	Dec. 31, 2016 USD ($) property	Sep. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2014 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2016 USD ($) property	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($) property	Apr. 14, 2016
Real Estate Properties
Discontinued operations transaction expenses																	$ 38,163
Dispositions
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net															$ 84,553	$ 250,516	158,308
Simon Property Group L.P.
Real Estate Properties
Discontinued operations transaction expenses																	38,163
Dispositions
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net															84,553	250,516	158,308
Outlet Center In Ochtrup
Acquisitions
Ownership interest (as a percent)									75.00%
Payments to acquire equity method investment									$ 38,300
Klepierre
Dispositions
Number of properties disposed of during the period \| property					126
Gain (loss) on disposition					$ 133,900
Ashford Designer Outlets \| European Joint Venture
Acquisitions
Additional noncontrolling interest purchased						22.50%
Joint venture ownership percentage after transactions						45.00%
Strip Center Business and Small Malls \| Spinoff
Real Estate Properties
Discontinued operations transaction expenses														$ 38,200			$ 38,200
Hotel, Estero, Florida \| Disposed by Sales \| Other income.
Dispositions
Gain (loss) on disposition of interest in properties				$ 4,500
Residential and Retail Properties \| Disposed by Sales
Dispositions
Proceeds from sale or disposal of real estate assets															$ 81,800
Scandinavian Properties \| Disposed by Sales \| Klepierre
Dispositions
Gain (loss) on disposition of interest in properties										$ 8,100
Outlet Centers In Italy
Acquisitions
Ownership interests acquired (as a percent)	33.00%
Number of consolidated properties under step acquisition \| property	2
Non-cash gain on step acquisition	$ 29,300										$ 29,300
Cash purchase price for acquisition	$ 145,500
The Shops at Crystals
Acquisitions
Ownership interests acquired (as a percent)																		50.00%
Jersey Gardens and University Park Village
Real Estate Properties
Acquisition related transaction costs																$ 4,400
Acquisitions
Ownership interests acquired (as a percent)			100.00%
Cash purchase price for acquisition			$ 677,900
Mortgage debt assumed			405,000
Investment properties			1,100,000
Mortgage debt premiums			17,900
Jersey Gardens and University Park Village \| Lease related intangibles
Acquisitions
Lease related intangibles			$ 3,600
Jersey Gardens and University Park Village \| Maximum
Acquisitions
Estimated life of investment property			40 years
Arizona Mills
Acquisitions
Ownership interests acquired (as a percent)							50.00%
Mortgage debt assumed							$ 166,900
Area of Real Estate Property \| a							39
Consideration paid							$ 145,800
Gain due to acquisition of controlling interest													$ 2,700
Ownership interest after acquisition (as a percent)							100.00%
Arizona Mills \| Simon Property Group L.P.
Acquisitions
Number of units issued in connection with acquisition of the remaining interest in Arizona Mills \| shares							555,150
Portfolio of ten properties
Acquisitions
Consideration paid								$ 114,400
Number of partner's interest acquired \| item								1
Number of properties in which additional interest is acquired \| property								10
Designer Outlet properties \| European Joint Venture
Acquisitions
Number of properties \| property		6														6
Designer Outlet properties \| European Joint Venture
Acquisitions
Number of consolidated properties under step acquisition \| property		2
Non-cash gain on step acquisition		$ 12,100										$ 12,100
Unconsolidated properties \| Maximum
Acquisitions
Estimated life of investment property															40 years
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															$ 36,200
Unconsolidated properties \| Residential properties \| Disposed by Sales \| Income and other taxes
Dispositions
Gain from sale of properties, tax effect															$ 7,200
Unconsolidated properties \| Retail properties \| Disposed by Sales
Dispositions
Number of properties disposed of during the period \| property															4	3
Gain (loss) on disposition of interest in properties															$ 22,600	$ 43,600
Unconsolidated properties \| Residential properties \| Disposed by Sales
Dispositions
Number of properties disposed of during the period \| property															2
Consolidated properties \| Retail properties \| Disposed by Sales
Dispositions
Number of properties disposed of during the period \| property															3		3
Gain (loss) on disposition															$ 12,400		$ 21,800
Consolidated properties \| Portfolio of ten properties
Acquisitions
Number of properties in which additional interest is acquired \| property								7
Consolidated properties \| Designer Outlet properties
Acquisitions
Number of properties \| property										4					4