Summary of Significant Accounting Policies - Rollforward Of Noncontrolling Interest, Simon Group Property L.P. (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Noncontrolling interests:
Net income attributable to noncontrolling nonredeemable interests	$ 289,594	$ 309,740	$ 241,023
Distributions to noncontrolling nonredeemable interest holders	(319,193)	(318,780)	(290,705)
Contributions by noncontrolling interests, net, and other	1,506	4,537	12,081
Simon Property Group L.P.
Noncontrolling interests:
Noncontrolling nonredeemable interests (deficit) in properties, beginning of period	3,456	(229)	4,264
Net income attributable to noncontrolling nonredeemable interests	2,917	2,984	2,491
Distributions to noncontrolling nonredeemable interest holders	(2,765)	(3,836)	(19,065)
Contributions by noncontrolling interests, net, and other	1,508	4,537	12,081
Noncontrolling nonredeemable interests (deficit) in properties, end of period	$ 5,116	$ 3,456	$ (229)