Disposals and Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended	1 Months Ended	3 Months Ended	1 Months Ended		3 Months Ended	1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2014	Jun. 30, 2014	May 31, 2014	Jun. 30, 2014	Oct. 31, 2014	Dec. 31, 2011	Jan. 31, 2014	Dec. 31, 2013	Apr. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price Gross			$ 18,615
Sales Price Net			17,886
Gain			937
Loss on impairment	0	17,150
Note receivable from sale of mall	19,609		19,811
Gain on Extinguishment of Debt	0	42,660
Pemberton Plaza
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price Gross				1,975
Sales Price Net				1,886
Gain				0
Loss on impairment					497
Foothills Plaza Expansion
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price Gross						2,640
Sales Price Net						2,387
Gain						937
Lakeshore Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price Gross							14,000
Sales Price Net							13,613
Gain							0
Loss on impairment		5,100						106
Columbia Place
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment										50,683
Balance of Non-recourse Debt									27,265
Gain on Extinguishment of Debt									27,171
Noncash or Part Noncash Divestiture, Interest Expense										3,181
Chapel Hill Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment			12,050
Balance of Non-recourse Debt				68,563
Gain on Extinguishment of Debt				18,296
Noncash or Part Noncash Divestiture, Interest Expense			1,514
Citadel Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment												20,453
Balance of Non-recourse Debt											68,169
Gain on Extinguishment of Debt											43,932
Notes Receivable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Note receivable from sale of mall	10,488		10,488
Notes Receivable | Lakeshore Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Note receivable from sale of mall							10,000
Cash | Lakeshore Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price Net							4,000
Fair Value, Inputs, Level 3 | Lakeshore Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Fair value of real estate investments													13,780
Columbia Place Chapel Hill and Citadel Mall
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Balance of Non-recourse Debt			163,997
Gain on Extinguishment of Debt			$ 89,399