Significant Accounting Policies - Reclassification Out of AOCI, Simon Property Group, Inc. (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Significant Accounting Policies
Interest expense	$ (198,202)	$ (219,190)
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net		22,688
Other income	61,299	84,250
Net income attributable to noncontrolling interests	(72,505)	(82,010)
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS	477,736	480,995
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		19,779
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		(117,027)
Accumulated derivative gains, net | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Interest expense	(2,620)	(2,905)
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net		372
Accumulated derivative gains, attributable to noncontrolling interests | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Net income attributable to noncontrolling interests	345	366
Accumulated derivative gains, attributable to parent | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS or UNITHOLDERS	$ (2,275)	$ (2,167)