Equity - Shares or Units Activity (Details) $ / shares in Units, $ in Millions			3 Months Ended
	Mar. 21, 2018 USD ($) shares	Feb. 13, 2017 USD ($)	Mar. 31, 2018 item $ / shares shares	Mar. 31, 2017 $ / shares shares
Equity
Stock repurchase program, extension period		2 years
Common stock authorized for repurchase | $		$ 2,000.0
Shares repurchased (in shares)			1,473,588	870,692
Average share price repurchased (in dollars per share) | $ / shares			$ 154.66	$ 174.22
Limited Partners
Equity
Exchange of limited partner units, (in shares)			6,000
Number of limited partners who received common stock | item			1
Simon Property Group, L.P. | Limited Partners
Equity
Redemption of units	40,503
Value of units redeemed | $	$ 6.3