Real Estate Acquisitions and Dispositions (Details) (USD $)	0 Months Ended				3 Months Ended	1 Months Ended		0 Months Ended			0 Months Ended		12 Months Ended	9 Months Ended			9 Months Ended		12 Months Ended		9 Months Ended	12 Months Ended	0 Months Ended
	May 21, 2012 Klepierre	Mar. 14, 2012 Klepierre	Jan. 06, 2012 Del Amo Fashion Center	May 03, 2012 The Domain, Austin, TX property	Sep. 30, 2013 Office property, Boston, Massachusetts	May 31, 2013 Outlet center, Portland OR	May 30, 2013 Outlet center, Portland OR sqft	Dec. 04, 2012 Grand Prairie and Livermore properties	Dec. 04, 2012 Grand Prairie Premium Outlets, Grand Prairie (Dallas), TX	Dec. 04, 2012 Livermore Premium Outlets, Livermore (San Francisco), CA	Jun. 04, 2012 Outlet center, Destin, FL sqft	Mar. 22, 2012 TMLP 2012 acquisition	Dec. 31, 2012 Retail properties	Sep. 30, 2013 Real estate property interests property	Mar. 22, 2012 Real estate property interests TMLP 2012 acquisition property	Mar. 22, 2012 Unconsolidated properties TMLP 2012 acquisition property	Sep. 30, 2013 Unconsolidated properties Community Centers property	Sep. 30, 2013 Unconsolidated properties Retail properties property	Dec. 31, 2012 Unconsolidated properties Retail properties property	Mar. 22, 2012 Consolidated properties TMLP 2012 acquisition property	Sep. 30, 2013 Consolidated properties Retail properties property	Dec. 31, 2012 Consolidated properties Retail properties property	Dec. 04, 2012 Consolidated properties Outlet center Grand Prairie and Livermore properties property
Real Estate Acquisitions and Dispositions
Number of properties in which additional interests acquired																	3						2
Number of properties disposed of during the period																	3	2	4		4	9
Gain on disposition				$ 12,400,000	$ 7,900,000								$ 15,500,000	$ 72,600,000
Property interest acquired (as a percent)							100.00%				50.00%
Area of property acquired (in square feet)							390,000				465,000
Property interest acquired						146,700,000					70,500,000
Gain on acquisition of property interests						27,300,000
Number of properties sold				2
Ownership interests acquired (as a percent)									50.00%	50.00%
Ownership interest after acquisition (as a percent)									100.00%	100.00%
Consideration paid								260,900,000
Consideration paid in cash, percentage								90.00%
Consideration paid by issuance of units, percentage								10.00%
Consideration paid								162,500,000
Number of properties														18	26	16				9
Transaction value												1,500,000,000
Joint venture ownership percentage		28.70%
Purchase price of equity method investment acquired		$ 2,000,000,000	$ 50,000,000
Joint venture ownership percentage after transactions	28.90%		50.00%