Per Share and Per Unit Data (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Per Share And Per Unit Data
Net Income attributable to Common Stockholders - Basic	$ 556,267	$ 513,783	$ 1,723,925	$ 1,373,509
Net Income attributable to Common Stockholders - Diluted	$ 556,267	$ 513,783	$ 1,723,925	$ 1,373,509
Weighted Average Shares Outstanding — Basic and Diluted	309,294,045	310,853,299	309,739,557	311,740,360
Simon Property Group, L.P.
Per Share And Per Unit Data
Net Income attributable to Common Stockholders - Basic	$ 640,402	$ 591,872	$ 1,984,527	$ 1,581,864
Net Income attributable to Common Stockholders - Diluted	$ 640,402	$ 591,872	$ 1,984,527	$ 1,581,864
Weighted Average Shares Outstanding — Basic and Diluted	356,073,080	358,115,572	356,562,262	359,029,893