Summary of Significant Accounting Policies - Discontinued Operations (Details) $ in Thousands		6 Months Ended	7 Months Ended	12 Months Ended
	May. 28, 2014 USD ($) property	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
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
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					262,652	$ 626,289
Property Operating					43,175	104,089
Depreciation and amortization					76,992	182,828
Real estate taxes					32,474	76,216
Repairs and maintenance					10,331	22,584
Advertising and promotion					3,340	8,316
Provision for credit losses					1,494	572
Other					2,028	4,664
Total operating expenses					169,834	399,269
OPERATING INCOME					92,818	227,020
Interest expense					(26,076)	(55,058)
Income and other taxes					(112)	(196)
Income (loss) from unconsolidated entities					652	(1,121)
Gain upon acquisition of controlling interests and sale or disposal of assets and interest in unconsolidated entities, net					242	14,152
CONSOLIDATED NET INCOME					67,524	184,797
Net income attributable to noncontrolling interests					9,781	26,571
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS					57,743	158,226
Additional disclosures
Capital expenditures on a cash basis					$ 31,900	$ 93,300
Washington Prime Group Inc | Transitional Services
Additional disclosures
Transition services fees earned			$ 3,200	$ 5,700
Washington Prime Group Inc | Spinoff | Strip Center Business and Small Malls
Discontinued Operations
Exchange ratio of common shares for entity's stockholders to receive under spin off	0.50
Additional disclosures
Term of property management agreement	2 years
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
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
Discontinued Operations
Exchange ratio of common units for entity's stockholders to receive under spin off	0.50