Investment in Unconsolidated Entities (Details) (USD $)	3 Months Ended			1 Months Ended			1 Months Ended		6 Months Ended			6 Months Ended
	Dec. 31, 2011	Jun. 30, 2012	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	Jun. 30, 2012 SPG-FCM	Mar. 22, 2012 SPG-FCM property	Jan. 06, 2012 Del Amo Fashion Center	Jun. 30, 2012 Klepierre	May 21, 2012 Klepierre	Mar. 14, 2012 Klepierre	Mar. 22, 2012 The Mills acquisition property	Jun. 30, 2012 United States joint ventures property	Dec. 31, 2011 United States joint ventures property	Jun. 30, 2012 Japan joint ventures property	Dec. 31, 2011 Japan joint ventures	Jun. 30, 2012 Mexico joint venture property	Jun. 30, 2012 South Korea joint ventures property	Dec. 31, 2011 South Korea joint ventures	Jun. 30, 2012 Malaysia joint venture property	Jan. 09, 2012 Italy property
Real Estate Joint Ventures
Number of income-producing properties																79	87	8		1	2		1	45
Interest in income-producing properties, under joint venture arrangements (as a percent)														28.70%
Ownership interest (as a percent)			50.00%			49.00%					50.00%	28.90%	28.90%					40.00%			50.00%
Purchase price of business acquired											$ 50,000,000
Additional Business Acquisition Percentage of Ownership Acquired											25.00%
Contribution to SPG-FCM ventures								50,000,000
Number of properties in which additional interest is acquired										26
Number of remaining unconsolidated properties										16
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	168,300,000								488,700,000
Other than temporary impairment charge									22,400,000
Estimated fair value of newly consolidated properties										4,300,000,000
Number of income-producing properties															9
Joint venture ownership percentage	50.00%
Investment in unconsolidated entities, at equity	1,378,084,000	2,000,509,000																335,900,000	349,500,000		58,300,000	43,800,000
Excess investment in acquisition of joint venture														1,200,000,000
Total revenues of Klepierre												407,700,000
Operating income of Klepierre												154,400,000
Consolidated net income of Klepierre												93,100,000
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
Number of shares owned in acquired entity												57,634,148
Quoted market price of shares owned in acquired entity (in dollars per share)												$ 32.80