Investments in Unconsolidated Entities and International Investments - Unconsolidated Property Transactions (Details) - USD ($) $ in Thousands		3 Months Ended
	Sep. 07, 2023	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023
Investment in Unconsolidated Entities
Payments for acquisitions						$ 27,712
Total revenue		$ 1,442,590				1,350,849
Operating income (loss) before other items		735,180				662,723
Consolidated net income (loss)		841,155				519,255
Gain (loss) on disposal, exchange, or revaluation of equity interests		414,769
TRG
Investment in Unconsolidated Entities
Total revenue		177,425				169,728
Operating income (loss) before other items		73,952				74,778
Consolidated net income (loss)		124,926				44,953
Our share of net income (loss)		104,790				34,848
Amortization of excess investment		(105,576)				(47,390)
Other Platform Investments
Investment in Unconsolidated Entities
Total revenue		2,757,083				2,956,722
Operating income (loss) before other items		(237,072)				(17,869)
Consolidated net income (loss)		(320,674)				(118,966)
Our share of net income (loss)		(87,046)				(37,789)
Amortization of excess investment		(692)				(1,665)
Simon Property Group, L.P.
Investment in Unconsolidated Entities
Payments for acquisitions						27,712
Total revenue		1,442,590				1,350,849
Operating income (loss) before other items		735,180				662,723
Consolidated net income (loss)		841,155				$ 519,255
Gain (loss) on disposal, exchange, or revaluation of equity interests		$ 414,769
Jamestown
Investment in Unconsolidated Entities
Ownership interest (as a percent)		50.00%
TRG
Investment in Unconsolidated Entities
Ownership interest (as a percent)	84.00%	84.00%
Payments for acquisitions	$ 199,600
Ownership interest acquired (as a percent)	4.00%
Aggregate investment in ventures		$ 3,004,129	$ 3,049,719
TRG | Series A Cumulative Preferred Shares
Investment in Unconsolidated Entities
Preferred stock stated dividend rate (as a percent)	6.38%
Issuance of preferred units	$ 362,500
TRG | Simon Property Group, L.P.
Investment in Unconsolidated Entities
Number of units issued in connection with acquisition (in units)	1,725,000
Aggregate investment in ventures		$ 3,004,129	3,049,719
JC Penney
Investment in Unconsolidated Entities
Ownership interest (as a percent)		41.67%
SPARC Group
Investment in Unconsolidated Entities
Ownership interest (as a percent)		33.30%		33.30%
Loans to related party		$ 100,000
Aggregate investment in ventures		94,400	$ 169,200
Guarantee provided		50,000
Gain (loss) on disposal, exchange, or revaluation of equity interests				$ 145,800
Deferred Taxes				$ 36,900
ABG
Investment in Unconsolidated Entities
Ownership interest (as a percent)			9.60%	11.70%
Gain (loss) on disposal, exchange, or revaluation of equity interests			$ 10,300	$ 12,400	$ 36,400
Deferred Taxes			2,600	$ 3,100	$ 9,100
Proceeds from sale or disposal of real estate assets		1,200,000	300,200
Pre-tax gain		414,800	157,100
Tax expense		$ 103,700	$ 39,300
RGG
Investment in Unconsolidated Entities
Ownership interest (as a percent)		45.00%