Investments in Unconsolidated Entities - International Investments (Details) $ / shares in Units, $ in Thousands, € in Millions								1 Months Ended	3 Months Ended				12 Months Ended
	Jul. 25, 2016 USD ($) property	Jan. 01, 2016 USD ($) property	May 11, 2015 USD ($) shares	Mar. 19, 2015 USD ($)	Jan. 15, 2015	Apr. 16, 2014 EUR (€) property	Apr. 16, 2014 USD ($) property	Feb. 29, 2016 USD ($)	Dec. 31, 2016 USD ($) property $ / shares shares	Sep. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) property $ / shares shares	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($)
Investment in Unconsolidated Entities
Equity investment									$ 2,367,583				$ 2,367,583	$ 2,481,574
Distribution from joint venture financing proceeds													331,627	271,998	$ 202,269
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net													84,553	250,516	158,308
Income from unconsolidated entities													$ 353,334	$ 284,806	$ 226,774
Ownership interest (as a percent)									86.90%				86.90%	85.70%
Cost method investments included in deferred costs and other assets									$ 210,500				$ 210,500	$ 181,400
Outlet Centers In Italy
Investment in Unconsolidated Entities
Cash purchase price for acquisition	$ 145,500
Gain due to acquisition of controlling interest	$ 29,300									$ 29,300
Number of consolidated properties under step acquisition | property	2
Ownership interests acquired (as a percent)	33.00%
Designer Outlet properties | European Joint Venture
Investment in Unconsolidated Entities
Gain due to acquisition of controlling interest		$ 12,100									$ 12,100
Number of consolidated properties under step acquisition | property		2
Designer Outlet properties | Minimum | European Joint Venture
Investment in Unconsolidated Entities
Ownership interest (as a percent)									45.00%				45.00%
Designer Outlet properties | Maximum | European Joint Venture
Investment in Unconsolidated Entities
Ownership interest (as a percent)									90.00%				90.00%
Klepierre
Investment in Unconsolidated Entities
Number of properties disposed of during the period | property						126	126
Total gross consideration | €						€ 1,980
Group's share of total consideration | €						€ 1,650
Gain upon acquisition of controlling interests and sale or disposal of assets and interest in unconsolidated entities, net							$ 133,900
Klepierre | Corio
Investment in Unconsolidated Entities
Ordinary share conversion ratio					1.14
Klepierre | Disposed by Sales | Scandinavian Properties
Investment in Unconsolidated Entities
Gain (loss) on disposition of interest in properties									$ 8,100
European Joint Venture | Designer Outlet properties
Investment in Unconsolidated Entities
Number of properties | property		6												6
Outlet Center In Ochtrup
Investment in Unconsolidated Entities
Ownership percentage								75.00%
Payments to acquire equity method investment								$ 38,300
Europe | Disposed by Sales | Pre-Development Europe Projects Joint Venture
Investment in Unconsolidated Entities
Aggregate proceeds received				$ 19,000
Gain on sale or disposal of assets and interests in unconsolidated entities, net				$ 8,300
Europe | Designer Outlet properties
Investment in Unconsolidated Entities
Number of properties | property									6				6
Europe | Klepierre
Investment in Unconsolidated Entities
Shares owned | shares									63,924,148				63,924,148
Ownership percentage			20.30%						20.30%			18.30%	20.30%		28.90%
Quoted market price per share (in dollars per share) | $ / shares									$ 39.50				$ 39.50
Gain upon acquisition of controlling interests and sale or disposal of assets and interests in unconsolidated entities, net												$ 206,900		$ 206,900
Additional shares acquired (in shares) | shares			6,290,000
Payments to acquire equity method investment			$ 279,400
Income from unconsolidated entities													$ 41,500	6,700	$ 131,500
Total assets									$ 19,800,000				19,800,000	20,800,000
Total liabilities									11,800,000				11,800,000	12,400,000
Noncontrolling interests equity									$ 1,400,000				1,400,000	1,400,000
Total revenues													1,500,000	1,500,000	1,200,000
Total operating income													449,900	414,800	432,100
Consolidated net income													$ 310,900	181,200	$ 1,300,000
Europe | Value Retail PLC
Investment in Unconsolidated Entities
Number of luxury outlets owned and operated | property									9				9
Number of outlets in which the entity has a minority direct ownership | property									3				3
Cost method investments included in deferred costs and other assets									$ 140,800				$ 140,800	$ 115,400