Equity - Shares or Units Activity (Details) $ / shares in Units, $ in Millions				3 Months Ended			6 Months Ended
	Jun. 29, 2020 $ / shares	Feb. 11, 2019 USD ($)	Feb. 13, 2017 USD ($)	Mar. 31, 2020 $ / shares shares	Jun. 30, 2019 $ / shares shares	Mar. 31, 2019 shares	Jun. 30, 2020 USD ($) item $ / shares shares	Jun. 30, 2019 $ / shares shares
Equity
Redemption of units				116,072		774
Exchange of limited partner units, (in shares)				132,946		24,000
Common stock authorized for repurchase | $		$ 2,000.0	$ 2,000.0
Period common stock is authorized to repurchase		2 years
Stock repurchase program, extension period			2 years
Shares repurchased (in shares)				1,245,654	1,046,580	46,377	1,245,654	1,092,957
Average share price repurchased (in dollars per share) | $ / shares							$ 122.50	$ 165.84
Common stock dividends paid (in dollars per share) | $ / shares				$ 2.10	$ 2.05			$ 4.10
Dividends declared per common share (in dollars per share) | $ / shares	$ 1.30
Limited Partners
Equity
Exchange of limited partner units, (in shares)							132,946
Number of limited partners who received common stock | item							4
2017 Share Repurchase Program
Equity
Shares repurchased (in shares)								46,377
Average share price repurchased (in dollars per share) | $ / shares								$ 164.49
Simon Property Group, L.P.
Equity
Redemption of units				116,072		774
Distributions paid per unit (in dollars per unit) | $ / shares				$ 2.10	$ 2.05			$ 4.10
Simon Property Group, L.P. | Limited Partners
Equity
Redemption of units							116,072
Number of limited partners who received common stock | item							2
Value of units redeemed | $							$ 16.1