Property, net - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Aug. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Mar. 01, 2018
Real Estate [Abstract]
Depreciation expense		$ 69,237	$ 69,343	$ 204,031	$ 207,663
Property, Plant and Equipment [Line Items]
Gain (loss) on sale or write down of assets, net		46,516	(11,854)	(514)	37,234
Outside partner interest of the operating partnership						75.00%
Write down of investment					(10,138)
South Park Mall
Property, Plant and Equipment [Line Items]
Impairment loss				36,338
Two freestanding stores
Property, Plant and Equipment [Line Items]
Impairment loss				7,494
Southridge Center
Property, Plant and Equipment [Line Items]
Impairment loss			$ 12,036	1,695	12,036
Promenade at Casa Grande
Property, Plant and Equipment [Line Items]
Gain (loss) on sale or write down of assets, net				(311)
Impairment loss				1,043
Cascade and Northgate Malls
Property, Plant and Equipment [Line Items]
Gain (loss) on disposal					$ 59,698
Joint Venture | Westside Pavilion
Property, Plant and Equipment [Line Items]
Gain on sale	$ 46,242	$ 46,242		$ 46,242
Outside partner interest of the operating partnership	75.00%