Summary of Significant Accounting Policies - Discontinued Operations (Details) $ in Thousands		6 Months Ended	12 Months Ended
	May 28, 2014 USD ($) property	Jun. 30, 2014 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 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
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			38,200
Summarized financial information for discontinued operations
TOTAL REVENUE					262,652
Property Operating					43,175
Depreciation and amortization					76,992
Real estate taxes					32,474
Repairs and maintenance					10,331
Advertising and promotion					3,340
Provision for credit losses					1,494
Other					2,028
Total operating expenses					169,834
OPERATING INCOME					92,818
Interest expense					(26,076)
Income and other taxes					(112)
Income from unconsolidated entities					652
Gain upon acquisition of controlling interests, sale or disposal of assets and interests in unconsolidated entities, and impairment charge on investment in unconsolidated entities, net					242
CONSOLIDATED NET INCOME					67,524
Net income attributable to noncontrolling interests					9,781
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS					57,743
Additional disclosures
Capital expenditures on a cash basis					31,900
Washington Prime Group Inc | Transitional Services
Additional disclosures
Transition services fees earned			$ 1,700	$ 5,700	$ 3,200
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 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