Acquisitions, Dispositions and Held for Sale (Details) - USD ($) $ in Thousands		1 Months Ended								3 Months Ended				6 Months Ended			12 Months Ended
		May 31, 2016	Apr. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Nov. 30, 2015	Jul. 31, 2015	Jun. 30, 2015	Apr. 30, 2015	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2015	Jun. 18, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross														$ 85,060			$ 104,860
Sales Price, Net														82,528			103,537
Gain														3,421			21,331
Loss on impairment										$ 43,493			$ 2,781	63,178		$ 2,781
Held for sale	[1]				$ 0					$ 65,300		$ 0		$ 65,300	$ 0		0
Real estate held-for-sale as a percentage of total assets										1.00%				1.00%
Liabilities related to assets held for sale					0					$ 38,237		0		$ 38,237	0		$ 0
River Ridge Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of equity interest in real estate property				25.00%						25.00%	25.00%			25.00%
Bonita Lakes Mall and Crossing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross		$ 27,910
Sales Price, Net		27,770
Gain		$ 140
Loss on impairment											$ 5,323
The Crossings at Marshalls Creek
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross			$ 23,650
Sales Price, Net			21,799
Gain			$ 3,281
River Ridge Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross				$ 33,500
Sales Price, Net				32,959
Gain				$ 0
Loss on impairment											$ 9,510
Ownership percentage sold				75.00%										75.00%
Mayfaire Community Center
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross					56,300
Sales Price, Net					55,955
Gain					0
Loss on impairment												397
Chapel Hill Crossing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross					2,300
Sales Price, Net					2,178
Gain					$ 0
Loss on impairment												1,914
Waynesville Commons
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross						$ 14,500
Sales Price, Net						14,289
Gain						$ 5,071
Madison Plaza
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross							$ 5,700
Sales Price, Net							5,472
Gain							$ 2,769
Eastgate Crossing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross								$ 21,060
Sales Price, Net								20,688
Gain								13,491
Earn out proceeds, amount earned										$ 508		625
Proceeds from lease of tenant space										$ 478		$ 574
Mortgage loan assumed at sale								$ 14,570
Madison Square
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price, Gross									$ 5,000
Sales Price, Net									4,955
Gain									$ 0
Loss on impairment													$ 2,620
Mayfaire Community Center
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business combination, ownership percentage																		100.00%
Sales price																		$ 191,988
Revenue from acquiree included in consolidated financial statements															8,982
Income from acquiree included in consolidated financial statements															$ 410

[1] As of June 30, 2016, includes $601,652 of assets related to consolidated variable interest entities that can be used only to settle obligations of the consolidated variable interest entities and $470,789 of liabilities of consolidated variable interest entities for which creditors do not have recourse to the general credit of the Company. See Note 5.