Equity - Changes in Equity, Simon Property Group, L.P. (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Increase (Decrease) in Stockholders' Equity
Redemption of limited partner units	$ (6,267)
Purchase and disposition of noncontrolling interests, net and other	(13,207)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and a $2,109 loss attributable to noncontrolling redeemable interests in properties	724,474
Comprehensive income attributable to preferred interests	479
Comprehensive loss attributable to noncontrolling redeemable interests in properties	619
Simon Property Group, L.P.
Increase (Decrease) in Stockholders' Equity
Balance	4,238,764
Treasury unit purchase	(227,901)
Redemption of limited partner units	(6,267)
LTIP Units	8,307
Purchase and disposition of noncontrolling interests, net and other	(13,207)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(698,098)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and a $2,109 loss attributable to noncontrolling redeemable interests in properties	724,474
Balance	4,033,336
Comprehensive income attributable to preferred interests	479
Comprehensive loss attributable to noncontrolling redeemable interests in properties	619
Simon Property Group, L.P. | Preferred Stock
Increase (Decrease) in Stockholders' Equity
Balance	43,077
Purchase and disposition of noncontrolling interests, net and other	(83)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(834)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and a $2,109 loss attributable to noncontrolling redeemable interests in properties	834
Balance	42,994
Simon Property Group, L.P. | Simon (Managing General Partner)
Increase (Decrease) in Stockholders' Equity
Balance	3,643,091
Limited partner units exchanged to units	70
Treasury unit purchase	(227,901)
Redemption of limited partner units	(5,793)
Purchase and disposition of noncontrolling interests, net and other	(13,148)
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	36,221
Distributions to limited partners, excluding preferred interests classified as temporary equity	(605,252)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and a $2,109 loss attributable to noncontrolling redeemable interests in properties	628,360
Balance	3,462,912
Simon Property Group, L.P. | Limited Partners
Increase (Decrease) in Stockholders' Equity
Balance	548,858
Limited partner units exchanged to units	(70)
Redemption of limited partner units	(474)
LTIP Units	8,307
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	(36,221)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(91,523)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and a $2,109 loss attributable to noncontrolling redeemable interests in properties	94,753
Balance	523,630
Simon Property Group, L.P. | Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity
Balance	3,738
Purchase and disposition of noncontrolling interests, net and other	24
Distributions to limited partners, excluding preferred interests classified as temporary equity	(489)
Comprehensive income, excluding $1,436 attributable to preferred interests in the Operating Partnership and a $2,109 loss attributable to noncontrolling redeemable interests in properties	527
Balance	3,800
Simon Property Group, L.P. | Accounting Standards Update 2016-01
Increase (Decrease) in Stockholders' Equity
Cumulative effect of accounting change	7,264
Simon Property Group, L.P. | Accounting Standards Update 2016-01 | Simon (Managing General Partner)
Increase (Decrease) in Stockholders' Equity
Cumulative effect of accounting change	$ 7,264