Investments in Unconsolidated Entities and International Investments - Unconsolidated Property Transactions (Details) - USD ($) $ in Thousands		3 Months Ended					6 Months Ended
	Sep. 07, 2023	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Investment in Unconsolidated Entities
Payments for acquisitions								$ 27,712
Total revenue		$ 1,458,266				$ 1,369,601	$ 2,900,856	2,720,450
Operating income (loss) before other items		754,101				657,925	1,489,281	1,320,648
Consolidated net income (loss)		569,435				557,505	1,410,591	1,076,760
Gain (loss) on disposal, exchange, or revaluation of equity interests						36,437	414,769	36,437
TRG
Investment in Unconsolidated Entities
Total revenue		164,104				163,097	341,529	332,825
Operating income (loss) before other items		60,115				61,916	134,067	136,694
Consolidated net income (loss)		24,892				25,722	149,818	70,675
Share of net income, net of tax		20,789				20,216	125,579	55,064
Amortization of excess investment		(57,206)				(47,390)	(162,782)	(94,780)
Other Platform Investments
Investment in Unconsolidated Entities
Total revenue		2,660,987				3,192,530	5,418,071	6,149,251
Operating income (loss) before other items		(31,530)				103,118	(277,327)	85,250
Consolidated net income (loss)		(77,036)				(9,401)	(397,710)	(128,366)
Share of net income, net of tax		(10,776)				8,053	(97,821)	(29,736)
Amortization of excess investment		(692)				(1,665)	(1,384)	(3,329)
Simon Property Group, L.P.
Investment in Unconsolidated Entities
Payments for acquisitions								27,712
Total revenue		1,458,266				1,369,601	2,900,856	2,720,450
Operating income (loss) before other items		754,101				657,925	1,489,281	1,320,648
Consolidated net income (loss)		$ 569,435				557,505	1,410,591	1,076,760
Gain (loss) on disposal, exchange, or revaluation of equity interests						36,437	$ 414,769	36,437
Jamestown
Investment in Unconsolidated Entities
Ownership interest (as a percent)		50.00%					50.00%
TRG
Investment in Unconsolidated Entities
Ownership interest (as a percent)	84.00%	84.00%					84.00%
Payments for acquisitions	$ 199,600
Ownership interest acquired (as a percent)	4.00%
Aggregate investment in ventures		$ 2,930,647		$ 3,049,719			$ 2,930,647
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		$ 2,930,647		3,049,719			$ 2,930,647
JC Penney
Investment in Unconsolidated Entities
Ownership interest (as a percent)		41.67%					41.67%
SPARC Group
Investment in Unconsolidated Entities
Ownership interest (as a percent)		33.30%			33.30%		33.30%
Loans to related party		$ 50,000	$ 100,000				$ 50,000
Proceeds from reimbursement of loans funded		50,000
Aggregate investment in ventures		65,400		$ 169,200			65,400
Guarantee provided		$ 50,000					$ 50,000
Gain (loss) on disposal, exchange, or revaluation of equity interests					$ 145,800
Deferred Taxes					$ 36,900
Phoenix Retail, LLC
Investment in Unconsolidated Entities
Ownership interest (as a percent)		39.40%					39.40%
Payments for acquisitions		$ 0
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		$ 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%					45.00%