Significant Accounting Policies - Reclassification Out Of AOCI, Simon Property Group, L.P. (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Significant Accounting Policies
Interest expense	$ (214,861)	$ (229,654)	$ (648,048)	$ (692,801)
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net	49,561		76,459	223,266
Other Income	54,370	72,545	198,986	260,736
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS	504,744	420,009	1,441,128	1,432,086
Simon Property Group L.P.
Significant Accounting Policies
Interest expense	(214,861)	(229,654)	(648,048)	(692,801)
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net	49,561		76,459	223,266
Other Income	54,370	72,545	198,986	260,736
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS	$ 581,266	$ 490,344	1,668,509	1,673,380
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			(118,833)
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			(7,758)	(6,936)
Accumulated derivative losses, attributable to parent | Simon Property Group L.P. | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Interest expense			(9,303)	(8,097)
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net			372
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS			$ (8,931)	(8,097)
Realized gain 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