Investments in Unconsolidated Entities and International Investments - Unconsolidated Entity Transactions (Details) $ / shares in Units, $ in Thousands					1 Months Ended	3 Months Ended				12 Months Ended			20 Months Ended	32 Months Ended
	Oct. 16, 2019 USD ($)	Sep. 25, 2018 $ / shares shares	Jun. 07, 2018 USD ($)	Sep. 15, 2016 item	Apr. 30, 2018 USD ($)	Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Sep. 19, 2019	May 31, 2017
Investment in Unconsolidated Entities
Gain upon acquisition of controlling interests, sale or disposal of, or recovery on, assets and interests in unconsolidated entities and impairment, net										$ 14,883	$ 288,827	$ 3,647
Insurance proceeds recorded as business interruption										5,662	19,083
Gain on interest in unconsolidated entities											35,621
Share of net income, net of amortization of our excess investment excluding impairment										444,349	475,250	400,270
Hotel
Investment in Unconsolidated Entities
Ownership interests acquired (as a percent)															50.00%
Ownership interest after acquisition (as a percent)															100.00%
Outlets at Orange
Investment in Unconsolidated Entities
Ownership interests acquired (as a percent)		50.00%
Ownership interest after acquisition (as a percent)		100.00%
Simon Property Group, L.P.
Investment in Unconsolidated Entities
Gain upon acquisition of controlling interests, sale or disposal of, or recovery on, assets and interests in unconsolidated entities and impairment, net										14,883	288,827	3,647
Insurance proceeds recorded as business interruption										5,662	19,083
Gain on interest in unconsolidated entities											35,621
Share of net income, net of amortization of our excess investment excluding impairment										444,349	475,250	400,270
Simon Property Group, L.P. | Outlets at Orange
Investment in Unconsolidated Entities
Number of units issued in connection with acquisition of the remaining interest in orange outlet | shares		475,183
Business acquisition price (in dollars per share) | $ / shares		$ 176.99
Aventura Mall
Investment in Unconsolidated Entities
Loan defeasance charge			$ 30,900
Write off of deferred debt issuance cost			6,500
Colorado Mills
Investment in Unconsolidated Entities
Impairment charges									$ 32,500
Insurance proceeds recorded as business interruption													$ 65,900	$ 67,900
Gain on business interruption										3,000	33,400
Mortgages | Aventura Mall
Investment in Unconsolidated Entities
Debt refinanced			1,200,000
Construction loan | Aventura Mall
Investment in Unconsolidated Entities
Debt refinanced			200,800
4.12% fixed interest rate mortgage maturing July 2028 | Aventura Mall
Investment in Unconsolidated Entities
Debt issued			$ 1,750,000
Fixed interest rate (as a percent)			4.12%
Aventura Mall
Investment in Unconsolidated Entities
Ownership interest (as a percent)			33.30%
Share of early debt repayment charge			$ 12,500
Colorado Mills
Investment in Unconsolidated Entities
Ownership interest (as a percent)																37.50%
Gain upon acquisition of controlling interests, sale or disposal of, or recovery on, assets and interests in unconsolidated entities and impairment, net										$ 1,100	$ 12,500
Aeropostale
Investment in Unconsolidated Entities
Number of joint ventures | item				2
Aeropostale Retail Operations
Investment in Unconsolidated Entities
Ownership interest (as a percent)						44.95%				44.95%				44.95%
Authentic Brands Group LLC
Investment in Unconsolidated Entities
Ownership interest (as a percent)						5.40%				5.40%				5.40%
Gain on interest in unconsolidated entities					$ 35,600
HBS
Investment in Unconsolidated Entities
Ownership interest (as a percent)						11.70%		11.70%		11.70%	11.70%		11.70%	11.70%
Impairment charge to reduce investment to its estimated fair value						$ 47,200
Share of net income, net of amortization of our excess investment excluding impairment										$ (16,200)	$ 15,100
Total revenues										133,400	326,300
Total operating income before other items										26,500	196,300
Consolidated net income										(24,700)	$ 105,900
HBS | Germany
Investment in Unconsolidated Entities
Gain upon acquisition of controlling interests, sale or disposal of, or recovery on, assets and interests in unconsolidated entities and impairment, net								$ 91,100
RGG
Investment in Unconsolidated Entities
Ownership interest (as a percent)	45.00%
Contribution to form joint venture	$ 276,800
Unconsolidated properties | Disposed by Sales | Retail properties
Investment in Unconsolidated Entities
Gain (loss) on disposition of interest in properties												$ (1,300)
Unconsolidated properties | Disposed by Sales | Residential properties
Investment in Unconsolidated Entities
Proceeds from sale or disposal of real estate assets							$ 17,900			17,900
Gain (loss) on disposition of interest in properties							$ 16,200			$ 16,200