Equity - Changes in Equity, 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
Increase (Decrease) in Stockholders' Equity
Balance			$ 5,216,369
LTIP Units			36,243
Purchase and disposition of noncontrolling interests, net and other			(1,947)
Distributions to common shareholders and limited partners, excluding Operating Partnership preferred interests			(1,756,660)
Distributions to other noncontrolling interest partners			(1,842)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and $4,666 attributable to noncontrolling redeemable interests in properties			1,834,650
Balance	$ 5,326,813		5,326,813
Comprehensive income attributable to preferred interests			1,436
Comprehensive income attributable to noncontrolling redeemable interests in properties			4,666
Preferred Stock or Units
Increase (Decrease) in Stockholders' Equity
Balance			43,733
Purchase and disposition of noncontrolling interests, net and other			(246)
Balance	43,487		43,487
Common Stock
Increase (Decrease) in Stockholders' Equity
Balance			31
Exchange of limited partner units for common shares			1
Balance	32		32
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity
Balance			(252,686)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and $4,666 attributable to noncontrolling redeemable interests in properties			136,854
Balance	(115,832)		(115,832)
Capital in Excess of Par Value
Increase (Decrease) in Stockholders' Equity
Balance			9,384,450
Exchange of limited partner units for common shares			70,100
Purchase and disposition of noncontrolling interests, net and other			(4,639)
Adjustment to limited partners' interest from change in ownership in the Operating Partnership			28,398
Balance	9,478,309		9,478,309
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity
Balance			(4,266,930)
Purchase and disposition of noncontrolling interests, net and other			(7,583)
Distributions to common shareholders and limited partners, excluding Operating Partnership preferred interests			(1,518,823)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and $4,666 attributable to noncontrolling redeemable interests in properties			1,443,631
Balance	(4,349,705)		(4,349,705)
Common Stock Held in Treasury
Increase (Decrease) in Stockholders' Equity
Balance			(437,134)
Purchase and disposition of noncontrolling interests, net and other			9,840
Balance	(427,294)		(427,294)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity
Balance	696,286	$ 766,261	744,905	$ 858,328
Exchange of limited partner units for common shares	(96)	(2)	(70,101)	(7,907)
LTIP Units			36,243
Purchase and disposition of noncontrolling interests, net and other	421	165	681	763
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	(9,433)	(9,791)	(28,398)	(91,294)
Distributions to common shareholders and limited partners, excluding Operating Partnership preferred interests			(237,837)
Distributions to other noncontrolling interest partners			(1,842)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and $4,666 attributable to noncontrolling redeemable interests in properties			254,165
Balance	$ 697,816	$ 758,031	$ 697,816	$ 758,031