Investments in Unconsolidated Entities and International Investments - Unconsolidated Entity Transactions (Details) $ / shares in Units, $ in Thousands						1 Months Ended	3 Months Ended						9 Months Ended		12 Months Ended
	Dec. 20, 2021 USD ($)	Jun. 01, 2021 USD ($)	Dec. 29, 2020 USD ($) property $ / shares shares	Dec. 07, 2020 USD ($)	Feb. 19, 2020 USD ($) item	Jan. 31, 2020 USD ($)	Sep. 30, 2022 USD ($) property	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($) item	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2022 USD ($) property	Sep. 30, 2021 USD ($)	Dec. 31, 2016 item
Investment in Unconsolidated Entities
Mortgages							$ 24,640,370	$ 25,321,022					$ 24,640,370
Payments for acquisitions													29,988	$ 157,080
Our share of net income, net of amortization of our excess investment							163,086		$ 198,524				434,343	562,138
Total revenue							1,315,786		1,296,554				3,891,550	3,790,652
Operating Income							652,196		612,324				1,899,348	1,821,658
Consolidated net income							621,847		778,648				1,679,637	1,994,977
Gain on exchange of equity interests									159,828					159,828
TRG
Investment in Unconsolidated Entities
Total revenue							161,503		152,043				504,034	436,409
Operating Income							57,355		51,893				192,414	137,368
Consolidated net income							35,500		25,224				123,304	55,364
Other Platform Investments
Investment in Unconsolidated Entities
Total revenue							3,543,438		3,560,993				10,247,196	9,675,055
Operating Income							337,119		445,670				596,234	975,286
Consolidated net income							280,999		410,258				454,606	869,766
Simon Property Group, L.P.
Investment in Unconsolidated Entities
Mortgages							24,640,370	25,321,022					24,640,370
Payments for acquisitions													29,988	157,080
Our share of net income, net of amortization of our excess investment							163,086		198,524				434,343	562,138
Total revenue							1,315,786		1,296,554				3,891,550	3,790,652
Operating Income							652,196		612,324				1,899,348	1,821,658
Consolidated net income							$ 621,847		778,648				$ 1,679,637	1,994,977
Gain on exchange of equity interests									159,828					159,828
TRG
Investment in Unconsolidated Entities
Ownership interest (as a percent)			80.00%				80.00%						80.00%
Share price (in dollars per share) | $ / shares			$ 43.00
Payments for acquisitions			$ 3,500,000
Our share of net income, net of amortization of our excess investment							$ (15,953)		(11,477)				$ (44,574)	(49,943)
Aggregate investment in ventures							3,150,169	3,305,102					3,150,169
TRG | Series J Cumulative Preferred Shares
Investment in Unconsolidated Entities
Redemption of preferred shares			$ 192,500
Preferred stock stated dividend rate (as a percent)			6.50%
TRG | Series K Cumulative Preferred Shares
Investment in Unconsolidated Entities
Redemption of preferred shares			$ 170,000
Preferred stock stated dividend rate (as a percent)			6.25%
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 | shares			955,705
Aggregate investment in ventures							$ 3,150,169	3,305,102					$ 3,150,169
TRG | TRG
Investment in Unconsolidated Entities
Number of regional, super regional and outlet malls | property			24				24						24
Eddie Bauer
Investment in Unconsolidated Entities
Ownership interest (as a percent)		49.00%
Payments for acquisitions		$ 100,800
J.C. Penny Department Store
Investment in Unconsolidated Entities
Ownership interest (as a percent)				41.67%
Payments for acquisitions				$ 125,000
Other Platform Investments
Investment in Unconsolidated Entities
Our share of net income, net of amortization of our excess investment							$ 61,462		106,306				$ 146,820	253,826
Forever 21
Investment in Unconsolidated Entities
Ownership interest (as a percent)											50.00%
Payments for acquisitions											$ 56,300
Number of joint ventures | item					2
Aggregate investment in ventures					$ 67,600
Bargain purchase gain												$ 35,000
Additional noncontrolling interest purchased											12.50%
SPARC Group
Investment in Unconsolidated Entities
Ownership interest (as a percent)							50.00%						50.00%
Number of joint ventures | item															2
SPARC Group Retail Operations
Investment in Unconsolidated Entities
Payments for acquisitions						$ 6,700
Additional noncontrolling interest purchased						5.05%
Authentic Brands Group LLC
Investment in Unconsolidated Entities
Payments for acquisitions						$ 33,500
Additional noncontrolling interest purchased						1.37%
ABG
Investment in Unconsolidated Entities
Ownership interest (as a percent)							10.40%						10.40%
Payments for acquisitions	$ 100,000
Aggregate investment in ventures									102,700					102,700
Gain on exchange of equity interests									159,800
Deferred Taxes									$ 47,900					$ 47,900
Pre-tax gain	18,800
Tax expense	$ 8,000
Unconsolidated properties | Disposed by Sales | Retail properties
Investment in Unconsolidated Entities
Proceeds from sale or disposal of real estate assets								3,000
Gain (loss) on disposition of interest in properties								$ 3,400
Unconsolidated properties | Disposed by Sales | Multi family residential property
Investment in Unconsolidated Entities
Proceeds from sale or disposal of real estate assets										$ 27,100
Gain (loss) on disposition of interest in properties										$ 14,900
Number of properties disposed of during the period | item										1
Unconsolidated properties | Discontinued Operations, Disposed of by Means Other than Sale [Member] | Retail properties
Investment in Unconsolidated Entities
Number of properties disposed of during the period | property							1
Gain on interest in unconsolidated entities							$ 19,900
Unconsolidated properties | Discontinued Operations, Disposed of by Means Other than Sale [Member] | Retail properties | Non-recourse $99.6M Mortgage
Investment in Unconsolidated Entities
Mortgages							$ 99,600						$ 99,600