Unconsolidated Affiliates, Redeemable Interests, Noncontrolling Interests and Cost Method Investments (Redeemable Interests, Noncontrolling Interests, Cost Method Investment and Variable Interest Entities) (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	May 31, 2016 USD ($)	Sep. 30, 2016 USD ($) shares	Jun. 30, 2016 USD ($) shareholder shares	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Mar. 31, 2016	Feb. 29, 2016	Dec. 31, 2015 USD ($)
Noncontrolling Interest [Line Items]
Percentage of equity interest in real estate property		50.00%		50.00%
Interest in note receivable contributed				$ 5,280	$ 0
Jinsheng
Noncontrolling Interest [Line Items]
Percentage ownership interest in qualified subsidiaries		6.20%		6.20%
Carrying amount of investment		$ 5,325		$ 5,325				$ 5,325
Third Party Interests
Noncontrolling Interest [Line Items]
Redeemable interests		19,536		19,536				19,744
Noncontrolling interests		97,393		97,393				109,753
Other Consolidated Subsidiaries
Noncontrolling Interest [Line Items]
Redeemable interests		3,206		3,206				5,586
Noncontrolling interests		12,960		12,960				4,876
Noncontrolling Interests
Noncontrolling Interest [Line Items]
Noncontrolling interests		110,353		$ 110,353				$ 114,629
Common Units
Noncontrolling Interest [Line Items]
Cash paid to common unit holders upon exercise of conversion rights		$ 11,608	$ 146
Number of units converted upon exercise of conversion rights | shares		950,000	14,796
Number of common unitholders who received cash for exercising conversion rights | shareholder			3
Laredo Outlet Shoppes, LLC | Parent Company
Noncontrolling Interest [Line Items]
Percentage of equity interest in real estate property	65.00%	65.00%		65.00%
Contribution amount	$ 7,714			$ 19,846
Cash contributed	2,434
Interest in note receivable contributed	$ 5,280
Capital contribution, percentage until pro rata basis is reached		100.00%		100.00%
Laredo Outlet Shoppes, LLC | Corporate Joint Venture
Noncontrolling Interest [Line Items]
Percentage of equity interest in real estate property	35.00%	35.00%		35.00%
Cash contributed by third party	$ 10,686
Triangle Town Center LLC | Parent Company
Noncontrolling Interest [Line Items]
Percentage of equity interest in real estate property						50.00%	50.00%
Triangle Town Center LLC | Corporate Joint Venture
Noncontrolling Interest [Line Items]
Percentage of equity interest in real estate property							50.00%