Property, Plant, and Equipment - Schedule of Loss (Gain) on Sale or Write down of Assets (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Aug. 31, 2018	May 17, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Mar. 01, 2018
Property, Plant and Equipment [Line Items]
Write-down of assets			$ 212	$ 1,786	$ 16,121	$ 50,578
(Loss) gain on sale or write down of assets, net			(131)	46,516	(15,506)	(514)
Outside partner interest of the operating partnership							75.00%
Write-down of assets			(212)	(1,786)	(16,121)	(50,578)
Promenade at Casa Grande
Property, Plant and Equipment [Line Items]
Write-down of assets						1,043
(Loss) gain on sale or write down of assets, net		$ (311)
Loss on sale						(311)
Write-down of assets						(1,043)
South Park Mall
Property, Plant and Equipment [Line Items]
Write-down of assets						36,338
Write-down of assets						(36,338)
Two freestanding stores
Property, Plant and Equipment [Line Items]
Write-down of assets						7,494
Write-down of assets						(7,494)
Southridge Center
Property, Plant and Equipment [Line Items]
Write-down of assets						1,695
Write-down of assets						(1,695)
Westside Pavilion | Joint Venture
Property, Plant and Equipment [Line Items]
Gain on sale	$ 46,242			$ 46,242		$ 46,242
Outside partner interest of the operating partnership	75.00%			75.00%		75.00%
Land
Property, Plant and Equipment [Line Items]
Gain on sale			81	$ 2,060	615	$ 4,133
Property
Property, Plant and Equipment [Line Items]
Gain on sale			$ 0	$ 46,242	$ 0	$ 45,931