Investments in Unconsolidated Entities - Balance Sheets (Details) $ in Thousands		12 Months Ended
	May. 28, 2014 property	Dec. 31, 2015 USD ($) property	Dec. 31, 2013 property	Dec. 31, 2014 USD ($)
Assets:
Investment properties, at cost		$ 33,463,124		$ 31,318,532
Less - accumulated depreciation		9,915,386		8,950,747
Investment properties at cost, net		23,547,738		22,367,785
Cash and cash equivalents		701,134		612,282
Tenant receivables and accrued revenue, net		624,605		580,197
Deferred costs and other assets		1,352,259		1,806,789
Liabilities and Partners' Deficit:
Mortgages		22,502,173		20,852,993
Accounts payable, accrued expenses, intangibles, and deferred revenues		1,323,801		1,259,681
Other liabilities		214,249		275,451
Total liabilities		25,408,767		23,555,288
Partners' deficit		(4,266,930)		(4,208,183)
Total liabilities and equity		30,650,673		29,532,330
Our Share of:
Our net investment in unconsolidated entities, at equity		2,481,574		2,378,800
Unconsolidated properties
Investments in Unconsolidated Entities
Number of unconsolidated properties in the spin-off of Washington Prime | property	10
Equity Method Investments | Unconsolidated properties
Assets:
Investment properties, at cost		17,186,884		16,087,282
Less - accumulated depreciation		5,780,261		5,457,899
Investment properties at cost, net		11,406,623		10,629,383
Cash and cash equivalents		818,805		993,178
Tenant receivables and accrued revenue, net		354,133		362,201
Investment in unconsolidated entities, at equity				11,386
Deferred costs and other assets		545,850		536,600
Total assets		13,125,411		12,532,748
Liabilities and Partners' Deficit:
Mortgages		13,891,041		13,272,557
Accounts payable, accrued expenses, intangibles, and deferred revenues		985,159		1,015,334
Other liabilities		468,005		493,718
Total liabilities		15,344,205		14,781,609
Preferred units		67,450		67,450
Partners' deficit		(2,286,244)		(2,316,311)
Total liabilities and equity		13,125,411		12,532,748
Our Share of:
Partners' deficit		(854,562)		(663,700)
Add: Excess investment		1,788,749		1,875,337
Our net investment in unconsolidated entities, at equity		$ 934,187		$ 1,211,637
Equity Method Investments | Unconsolidated properties | Retail properties
Investments in Unconsolidated Entities
Number of properties disposed of during the period | property		3	3