Significant Accounting Policies (Details 8) $ in Thousands		3 Months Ended		6 Months Ended
	May. 28, 2014 USD ($) property	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)
Discontinued Operations
Amount of retained proceeds from recently completed unsecured debt and mortgage debt as part of the spin-off					$ 1,003,135
Transaction Expenses
Discontinued operations transaction expenses			$ 38,163		38,163
Spinoff | Strip Center Business and Small Malls
Discontinued Operations
Number of properties merged under spin off into Washington Prime, an independent publicly traded REIT | property	98
Amount of retained proceeds from recently completed unsecured debt and mortgage debt as part of the spin-off	$ 1,000,000
Transaction Expenses
Discontinued operations transaction expenses					38,200
Summarized financial information for discontinued operations
TOTAL REVENUE			104,683		262,652
Property operating			17,035		43,175
Depreciation and amortization			31,024		76,992
Real estate taxes			12,526		32,474
Repairs and maintenance			3,181		10,331
Advertising and promotion			1,388		3,340
Provision for credit losses			708		1,494
Other			910		2,028
Total operating expenses			66,772		169,834
OPERATING INCOME			37,911		92,818
Interest expense			(12,159)		(26,076)
Income and other taxes			(37)		(112)
Income from unconsolidated entities			307		652
Gain upon acquisition of controlling interests and sale or disposal of assets and interest in unconsolidated entities, net					242
CONSOLIDATED NET INCOME			26,022		67,524
Net income attributable to noncontrolling interests			3,792		9,781
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS			22,230		57,743
Additional disclosures
Capital expenditures on a cash basis			$ 7,100		$ 31,900
Washington Prime Group Inc | Transitional Services
Additional disclosures
Transition services fees earned		$ 1,600		$ 2,900
Washington Prime Group Inc | Spinoff | Strip Center Business and Small Malls
Additional disclosures
Term of property management agreement	2 years
Renewal term of property management agreement	1 year
Termination period of property management agreement	2 years
Period of prior written notice for termination of property management agreement	180 days
Termination period of transition services agreement	2 years
Minimum notice period for transition services agreement	180 days
Minimum notice period as percentage of original service period	50.00%
Exchange ratio of common shares for entity's stockholders to receive under spin off	0.50
Washington Prime Group Inc | Minimum
Additional disclosures
Annual fixed rate property management fees (as a percent)				2.50%
Washington Prime Group Inc | Maximum
Additional disclosures
Annual fixed rate property management fees (as a percent)				4.00%
Washington Prime Group LP | Spinoff | Strip Center Business and Small Malls
Additional disclosures
Exchange ratio of common units for entity's stockholders to receive under spin off	0.50