Equity - Changes in Equity, Simon Property Group, Inc. (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Increase (Decrease) in Stockholders' Equity
Balance			$ 5,216,369
LTIP Units			24,162
Purchase and disposition of noncontrolling interests, net and other			(9,574)
Distributions to common shareholders and limited partners, excluding Operating Partnership preferred interests			(1,159,575)
Distributions to other noncontrolling interest partners			(1,202)
Comprehensive income, excluding $957 attributable to preferred distributions on temporary equity preferred units and a $44 loss attributable to noncontrolling redeemable interests in properties			1,247,197
Balance	$ 5,317,377		5,317,377
Comprehensive income attributable to preferred interests			957
Comprehensive income attributable to noncontrolling redeemable interests in properties			44
Preferred Stock or Units
Increase (Decrease) in Stockholders' Equity
Balance			43,733
Purchase and disposition of noncontrolling interests, net and other			(164)
Balance	43,569		43,569
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 $957 attributable to preferred distributions on temporary equity preferred units and a $44 loss attributable to noncontrolling redeemable interests in properties			132,771
Balance	(119,915)		(119,915)
Capital in Excess of Par Value
Increase (Decrease) in Stockholders' Equity
Balance			9,384,450
Exchange of limited partner units for common shares			70,004
Purchase and disposition of noncontrolling interests, net and other			(7,557)
Adjustment to limited partners' interest from change in ownership in the Operating Partnership			18,965
Balance	9,465,862		9,465,862
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity
Balance			(4,266,930)
Purchase and disposition of noncontrolling interests, net and other			(12,106)
Distributions to common shareholders and limited partners, excluding Operating Partnership preferred interests			(1,000,333)
Comprehensive income, excluding $957 attributable to preferred distributions on temporary equity preferred units and a $44 loss attributable to noncontrolling redeemable interests in properties			938,053
Balance	(4,341,316)		(4,341,316)
Common Stock Held in Treasury
Increase (Decrease) in Stockholders' Equity
Balance			(437,134)
Purchase and disposition of noncontrolling interests, net and other			9,993
Balance	(427,141)		(427,141)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity
Balance	771,957	$ 858,611	744,905	$ 858,328
Exchange of limited partner units for common shares	(69,989)	(56)	(70,005)	(7,905)
LTIP Units			24,162
Purchase and disposition of noncontrolling interests, net and other	260	415	260	598
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	(13,822)	(75,905)	(18,965)	(81,503)
Distributions to common shareholders and limited partners, excluding Operating Partnership preferred interests			(159,242)
Distributions to other noncontrolling interest partners			(1,202)
Comprehensive income, excluding $957 attributable to preferred distributions on temporary equity preferred units and a $44 loss attributable to noncontrolling redeemable interests in properties			176,373
Balance	$ 696,286	$ 766,261	$ 696,286	$ 766,261