Investment in Unconsolidated Entities (Details 7) (USD $) In Thousands, unless otherwise specified					12 Months Ended	9 Months Ended	12 Months Ended				9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011	Dec. 31, 2012 Mall property	Sep. 30, 2013 Retail Properties property	Dec. 31, 2012 Retail Properties property	Mar. 22, 2012 TMLP 2012 acquisition Consolidated property interests property	Sep. 30, 2013 Equity Method Investments Unconsolidated property interests	Dec. 31, 2012 Equity Method Investments Unconsolidated property interests	Sep. 30, 2013 Equity Method Investments Unconsolidated property interests Maximum
Schedule of Equity Method Investments
Number of properties								9
Number of joint venture interests sold					1	2	3
Assets:
Investment properties, at cost	$ 34,764,669	$ 34,252,521							$ 14,828,264	$ 14,607,291
Less - accumulated depreciation	9,804,069	9,068,388							5,144,189	4,926,511
Investment properties, net	24,960,600	25,184,133							9,684,075	9,680,780
Cash and cash equivalents	1,099,321	1,184,518	452,712	798,650					653,185	619,546
Tenant receivables and accrued revenue, net	529,893	521,301							270,770	252,774
Investment in unconsolidated entities, at equity									38,669	39,589
Deferred costs and other assets	1,558,465	1,570,734							442,831	438,399
Total assets									11,089,530	11,031,088
Liabilities and Partners' Deficit:
Mortgages and unsecured indebtedness	22,729,654	23,113,007							11,979,021	11,584,863
Accounts payable, accrued expenses, intangibles, and deferred revenue	1,328,089	1,374,172							723,143	672,483
Other liabilities	227,319	303,588							394,461	447,132
Total liabilities	25,127,124	25,515,511							13,096,625	12,704,478
Preferred units	44,472	44,719							67,450	67,450
Partners' deficit									(2,074,545)	(1,740,840)
Total liabilities and equity	32,111,409	32,586,606							11,089,530	11,031,088
Our Share of:
Partners' deficit									(943,037)	(799,911)
Add: Excess Investment									2,092,875	2,184,133
Our net Investment in unconsolidated entities, at equity	$ 1,991,900	$ 2,108,966							$ 1,149,838	$ 1,384,222
Life of joint ventures with excess investment											40 years