Per Share and Per Unit Data (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Per Share And Per Unit Data
Net Income attributable to Common Stockholders - Basic	$ 620,654	$ 477,736
Net Income attributable to Common Stockholders - Diluted	$ 620,654	$ 477,736
Weighted Average Shares Outstanding — Basic and Diluted	310,583,643	312,809,981
Simon Property Group, L.P.
Per Share And Per Unit Data
Net Income attributable to Common Stockholders - Basic	$ 714,303	$ 550,006
Net Income attributable to Common Stockholders - Diluted	$ 714,303	$ 550,006
Weighted Average Shares Outstanding — Basic and Diluted	357,446,988	360,130,442