Investments in Unconsolidated Entities and International Investments - Combined Balance Sheets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Our Share of:
Our net Investment in unconsolidated entities, at equity	$ 1,628,343	$ 1,731,649
Unconsolidated properties | Maximum
Our Share of:
Estimated life of investment property	40 years
Equity Method Investees excluding Klepierre, Aeropostale, ABG, HBS, RGG and Forever 21 | Unconsolidated properties
Assets:
Investment properties, at cost	$ 19,500,080	19,525,665
Less - accumulated depreciation	7,493,263	7,407,627
Investment properties at cost, net	12,006,817	12,118,038
Cash and cash equivalents	844,940	1,015,864
Tenant receivables and accrued revenue, net	445,799	510,157
Right-of-use assets, net	180,638	185,302
Deferred costs and other assets	371,875	384,663
Total assets	13,850,069	14,214,024
Liabilities and Partners' Deficit:
Mortgages	15,328,574	15,391,781
Accounts payable, accrued expenses, intangibles, and deferred revenue	789,129	977,112
Lease liabilities	182,465	186,594
Other liabilities	362,323	338,412
Total liabilities	16,662,491	16,893,899
Preferred units	67,450	67,450
Partners' deficit	(2,879,872)	(2,747,325)
Total liabilities and partners' deficit	13,850,069	14,214,024
Our Share of:
Partners' deficit	(1,248,877)	(1,196,926)
Add: Excess Investment	1,504,586	1,525,903
Our net Investment in unconsolidated entities, at equity	$ 255,709	$ 328,977