Summary of Significant Accounting Policies - Reclassification Out Of AOCI, Simon Property Group, L.P. (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Significant Accounting Policies
Interest expense									$ (857,554)	$ (923,697)	$ (992,601)
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net									84,553	250,516	158,308
Other Income									276,544	325,597	200,781
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS	$ 394,431	$ 504,744	$ 455,389	$ 480,995	$ 392,297	$ 420,009	$ 472,944	$ 539,134	1,835,559	1,824,383	1,405,251
Simon Property Group L.P.
Significant Accounting Policies
Interest expense									(857,554)	(923,697)	(992,601)
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net									84,553	250,516	158,308
Other Income									276,544	325,597	200,781
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS	$ 453,726	$ 581,266	$ 525,447	$ 561,797	$ 457,759	$ 490,344	$ 552,604	$ 630,432	2,122,236	2,131,139	1,643,783
Currency translation adjustments, attributable to parent | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS									(118,858)
Currency translation adjustments, attributable to parent | Simon Property Group L.P. | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net									(136,806)
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS									(136,806)
Accumulated derivative losses, attributable to parent | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS									(11,135)	(9,421)	(9,221)
Accumulated derivative losses, attributable to parent | Simon Property Group L.P. | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Interest expense									(12,230)	(10,998)	(10,789)
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net									(586)
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS									$ (12,816)	(10,998)	$ (10,789)
Net unrealized gains on sale of marketable securities | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS										68,685
Net unrealized gains on sale of marketable securities | Simon Property Group L.P. | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Other Income										80,187
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS										$ 80,187