Investments in Unconsolidated Entities - Combined Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
OPERATING EXPENSES:
Income from Unconsolidated Entities	$ 134,408	$ 116,110	$ 325,263	$ 277,212
Equity Method Investees excluding Klepierre, Aeropostale and HBS | Unconsolidated properties
REVENUE:
Minimum rent	483,685	466,601	1,443,617	1,383,361
Overage rent	52,417	52,560	163,144	150,376
Tenant reimbursements	222,153	215,774	666,068	644,020
Other income	73,259	74,208	232,747	210,287
Total revenue	831,514	809,143	2,505,576	2,388,044
OPERATING EXPENSES:
Property operating	151,873	145,288	437,718	410,301
Depreciation and amortization	161,964	156,682	488,098	469,884
Real estate taxes	60,654	54,668	197,497	185,228
Repairs and maintenance	20,035	18,811	63,968	59,512
Advertising and promotion	20,318	19,837	65,425	63,871
Provision for credit losses	1,300	1,063	13,378	7,629
Other	43,916	45,174	143,533	133,558
Total operating expenses	460,060	441,523	1,409,617	1,329,983
Operating Income	371,454	367,620	1,095,959	1,058,061
Interest expense	(163,855)	(149,746)	(505,540)	(438,393)
Gain on sale or disposal of, or recovery on, assets and interests in unconsolidated entities, net			25,792
Net Income	207,599	217,874	616,211	619,668
Third-Party Investors’ Share of Net Income	101,750	110,581	304,174	314,531
Our Share of Net Income	105,849	107,293	312,037	305,137
Amortization of Excess Investment	(21,526)	(22,608)	(64,447)	(68,045)
Our Share of Gain on Sale or Disposal of, or Recovery on, Assets and Interests in Unconsolidated Entities, net			(9,672)
Income from Unconsolidated Entities	$ 84,323	$ 84,685	$ 237,918	$ 237,092