Investment in Unconsolidated Entities (Details) (USD $)	3 Months Ended		9 Months Ended				1 Months Ended			1 Months Ended		9 Months Ended		6 Months Ended				3 Months Ended	1 Months Ended	3 Months Ended		9 Months Ended	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Dec. 09, 2011	Jan. 31, 2012 GCI	Jan. 09, 2012 GCI	Dec. 31, 2011 GCI	Mar. 31, 2012 SPG-FCM	Jan. 31, 2012 SPG-FCM	Sep. 30, 2012 SPG-FCM	Mar. 22, 2012 SPG-FCM property	Sep. 30, 2012 Klepierre	May 21, 2012 Klepierre	Mar. 14, 2012 Klepierre	Jan. 06, 2012 Del Amo Fashion Center	Sep. 30, 2012 Malls property	Jun. 30, 2011 Other Retail Property property	Sep. 30, 2012 Other Retail Property property	Mar. 31, 2012 Other Retail Property property	Sep. 30, 2011 Other Retail Property property	Dec. 31, 2011 Dissolved Joint Venture Partnership	Mar. 22, 2012 The Mills acquisition property	Sep. 30, 2012 United States joint ventures property	Dec. 31, 2011 United States joint ventures property	Sep. 30, 2012 Japan joint ventures property	Dec. 31, 2011 Japan joint ventures	Sep. 30, 2012 South Korea joint ventures property	Dec. 31, 2011 South Korea joint ventures	Sep. 30, 2012 Mexico joint venture property	Sep. 30, 2012 Malaysia joint venture property	Jan. 09, 2012 Italy property
Real Estate Joint Ventures
Number of income-producing properties																									75	87	8		2		1	1	45
Additional Business Acquisition Percentage of Ownership Acquired																	25.00%
Interest in income-producing properties, under joint venture arrangements (as a percent)																28.70%
Ownership interest (as a percent)						50.00%			49.00%					28.90%	28.90%		50.00%										40.00%		50.00%
Purchase price of business acquired																	$ 50,000,000
Contribution to SPG-FCM ventures											50,000,000
Number of properties in which additional interest is acquired													26
Number of remaining unconsolidated properties													16
Previously unconsolidated properties																								9
Cost of acquisition including assumption of debt													1,500,000,000			2,000,000,000
Debt obligation related to consolidated properties disposed of													562,100,000
Trust preferred securities retired										100,000,000
Related party debt obligations extinguished during the period										558,400,000
Mortgage indebtedness assumed													2,600,000,000
Gain due to acquisition of controlling interest												488,700,000											168,300,000
Other than temporary impairment charge												22,400,000
Estimated fair value of newly consolidated properties													4,300,000,000
Excess investment in acquisition of joint venture																1,200,000,000
Total revenues of Klepierre														748,900,000
Operating income of Klepierre														292,200,000
Consolidated net income of Klepierre														187,100,000
Income from unconsolidated entities	37,129,000	17,120,000	96,613,000	49,561,000										4,700,000
Number of shares owned in acquired entity														57,634,148
Quoted market price of shares owned in acquired entity (in dollars per share)														$ 35.08
Proceeds from sale of interest in joint venture							375,800,000
Gain on sale of or disposal of assets and interests in unconsolidated entities, net							28,800,000
Accumulated losses reclassified								39,500,000
Investment in unconsolidated entities, at equity	$ 2,013,651,000		$ 2,013,651,000		$ 1,378,084,000																						$ 341,100,000	$ 349,500,000	$ 60,000,000	$ 43,800,000
Joint venture ownership percentage																							50.00%
Number of properties disposed																		1	1	3	1	3