Investments in Unconsolidated Entities and International Investments - Unconsolidated Entity Transactions (Details) $ / shares in Units, $ in Thousands					1 Months Ended		3 Months Ended
	Dec. 20, 2021 USD ($)	Jun. 01, 2021 USD ($)	Dec. 29, 2020 USD ($) property $ / shares shares	Feb. 19, 2020 USD ($) item	Jan. 31, 2020 USD ($)	Dec. 31, 2016 item	Mar. 31, 2022 USD ($) property	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($) item	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)
Investment in Unconsolidated Entities
Payments for acquisitions											$ 56,250
Income from unconsolidated entities							$ 81,184				15,069
Total revenue							1,295,922				1,239,951
Operating Income							620,391				604,612
Consolidated net income							488,310				510,460
Simon Property Group, L.P.
Investment in Unconsolidated Entities
Payments for acquisitions											56,250
Income from unconsolidated entities							81,184				15,069
Total revenue							1,295,922				1,239,951
Operating Income							620,391				604,612
Consolidated net income							488,310				510,460
TRG | TRG
Investment in Unconsolidated Entities
Total revenue							162,600				135,400
Operating Income							61,900				36,800
Consolidated net income							$ 38,700				8,700
TRG
Investment in Unconsolidated Entities
Ownership interest (as a percent)			80.00%				80.00%
Share price (in dollars per share) | $ / shares			$ 43.00
Payments for acquisitions			$ 3,500,000
Income from unconsolidated entities							$ (18,500)				(24,800)
Aggregate investment in ventures							3,276,296	$ 3,305,102
Amortization of Excess Investment							49,000				$ 31,600
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							$ 3,276,296	3,305,102
TRG | TRG
Investment in Unconsolidated Entities
Number of regional, super regional and outlet malls | property			24				24
Eddie Bauer
Investment in Unconsolidated Entities
Ownership interest (as a percent)		49.00%
Payments for acquisitions		$ 100,800
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
Number of joint ventures | item						2
SPARC Group Retail Operations
Investment in Unconsolidated Entities
Ownership interest (as a percent)							50.00%
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%
Gain on exchange of equity interests									$ 159,800
Deferred Taxes									$ 47,900
Pre-tax gain	$ 18,800
Tax expense	8,000
Purchase price of business acquired	$ 100,000
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