Significant Accounting Policies - Reclassification Out of AOCI, Simon Property Group, Inc. (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
Net income attributable to noncontrolling interests	$ (82,362)	$ (71,653)	$ (235,472)	$ (244,868)
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
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS	504,744	420,009	1,441,128	1,432,086
Other income	$ 54,370	$ 72,545	198,986	260,736
Currency translation adjustments | 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)
Currency translation adjustments, attributable to noncontrolling interests | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Net income attributable to noncontrolling interests			17,973
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)
Accumulated derivative losses, net | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Interest expense			(9,303)	(8,097)
Accumulated derivative losses, attributable to noncontrolling interests | 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			372
Accumulated derivative losses, attributable to parent | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Net income attributable to noncontrolling interests			1,173	1,161
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS			$ (7,758)	(6,936)
Realized gain on sale of marketable securities, including Portion Attributable to Noncontrolling Interest | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Other income				80,187
Realized gain on sale of marketable securities, attributable to Noncontrolling Interest | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Net income attributable to noncontrolling interests				(11,502)
Realized gain 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