Document and Entity Information - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
Entity Registrant Name	SIMON PROPERTY GROUP, INC.
Entity Central Index Key	0001063761
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2019
Entity File Number	001-14469
Entity Tax Identification Number	04-6268599
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	225 West Washington Street
Entity Address, City or Town	Indianapolis
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46204
City Area Code	317
Local Phone Number	636-1600
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 48,849
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Common stock
Title of 12(b) Security	Common stock, $0.0001 par value
Trading Symbol	SPG
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		306,860,960
Entity Listing, Par Value Per Share	$ 0.0001
Class B common stock
Entity Common Stock, Shares Outstanding		8,000
Entity Listing, Par Value Per Share	$ 0.0001
Series J Preferred stock
Title of 12(b) Security	83/8% Series J Cumulative Redeemable Preferred Stock, $0.0001 par value
Trading Symbol	SPGJ
Security Exchange Name	NYSE
Simon Property Group, L.P.
Entity Registrant Name	SIMON PROPERTY GROUP, L.P.
Entity Central Index Key	0001022344
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2019
Entity File Number	001-36110
Entity Tax Identification Number	34-1755769
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	225 West Washington Street
Entity Address, City or Town	Indianapolis
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46204
City Area Code	317
Local Phone Number	636-1600
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Simon Property Group, L.P. | Senior Unsecured 2.375% due 2020
Title of 12(b) Security	2.375% Senior Unsecured Notes due 2020
Trading Symbol	SPG/20
Security Exchange Name	NYSE