Investments in Unconsolidated Entities - Combined Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
OPERATING EXPENSES:
Income from Unconsolidated Entities	$ 100,828	$ 92,017	$ 190,854	$ 161,101
Equity Method Investees excluding Klepierre, Aeropostale and HBS | Unconsolidated properties
REVENUE:
Minimum rent	483,976	465,705	959,931	916,760
Overage rent	51,067	46,447	110,728	97,816
Tenant reimbursements	220,426	212,465	443,916	428,246
Other income	78,378	71,753	159,487	136,079
Total revenue	833,847	796,370	1,674,062	1,578,901
OPERATING EXPENSES:
Property operating	139,553	132,028	285,845	265,013
Depreciation and amortization	166,299	159,748	326,134	313,202
Real estate taxes	68,576	63,977	136,843	130,560
Repairs and maintenance	20,736	20,471	43,933	40,701
Advertising and promotion	20,884	21,836	45,108	44,034
Provision for credit losses	5,577	2,789	12,078	6,566
Other	49,885	45,030	99,617	88,384
Total operating expenses	471,510	445,879	949,558	888,460
Operating Income	362,337	350,491	724,504	690,441
Interest expense	(190,751)	(146,440)	(341,684)	(288,647)
Gain on sale or disposal of, or recovery on, assets and interests in unconsolidated entities, net	25,792		25,792
Net Income	197,378	204,051	408,612	401,794
Third-Party Investors’ Share of Net Income	96,240	104,265	202,424	203,950
Our Share of Net Income	101,138	99,786	206,188	197,844
Amortization of Excess Investment	(21,395)	(22,979)	(42,921)	(45,436)
Our Share of Gain on Sale or Disposal of, or Recovery on, Assets and Interests in Unconsolidated Entities, net	(9,672)		(9,672)
Income from Unconsolidated Entities	$ 70,071	$ 76,807	$ 153,595	$ 152,408