Investment in Unconsolidated Entities (Details 7) $ in Thousands		6 Months Ended
	May. 28, 2014 property	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Assets:
Investment properties, at cost		$ 32,898,773	$ 31,318,532
Less - accumulated depreciation		9,409,100	8,950,747
Investment properties, net		23,489,673	22,367,785
Cash and cash equivalents		565,657	612,282
Tenant receivables and accrued revenue, net		537,172	580,197
Deferred costs and other assets		1,333,944	1,806,789
Liabilities and Partners' Deficit:
Mortgages and unsecured indebtedness		22,070,777	20,852,993
Accounts payable, accrued expenses, intangibles, and deferred revenues		1,215,444	1,259,681
Other liabilities		248,596	275,451
Total liabilities		24,878,845	23,555,288
Partners' deficit		(4,274,289)	(4,208,183)
Total liabilities and equity		30,083,531	29,532,330
Our Share of:
Our net investment in unconsolidated entities, at equity		2,353,339	2,378,800
Unconsolidated properties
Our Share of:
Number of properties merged under spin off into Washington Prime, an independent publicly traded REIT | property	10
Equity Method Investments | Unconsolidated properties
Assets:
Investment properties, at cost		16,790,264	16,087,282
Less - accumulated depreciation		5,611,016	5,457,899
Investment properties, net		11,179,248	10,629,383
Cash and cash equivalents		885,430	993,178
Tenant receivables and accrued revenue, net		333,033	362,201
Investment in unconsolidated entities, at equity			11,386
Deferred costs and other assets		533,447	536,600
Total assets		12,931,158	12,532,748
Liabilities and Partners' Deficit:
Mortgages and unsecured indebtedness		13,801,561	13,272,557
Accounts payable, accrued expenses, intangibles, and deferred revenues		940,309	1,015,334
Other liabilities		386,277	493,718
Total liabilities		15,128,147	14,781,609
Preferred units		67,450	67,450
Partners' deficit		(2,264,439)	(2,316,311)
Total liabilities and equity		12,931,158	12,532,748
Our Share of:
Partners' deficit		(820,782)	(663,700)
Add: Excess investment		1,830,093	1,875,337
Our net investment in unconsolidated entities, at equity		$ 1,009,311	$ 1,211,637
Equity Method Investments | Unconsolidated properties | Maximum
Our Share of:
Life of joint ventures with excess investment		40 years