Real Estate Investments - Summary of Properties Classified as Held for Sale Included in Continuing Operations (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
ASSETS HELD FOR SALE
Total assets held for sale, net	$ 6,262	$ 41,718
LIABILITIES HELD FOR SALE
Total liabilities held for sale	387	$ 81
Held for Sale Properties Included in Continuing Operations [Member] \| Other Segment - Retail [Member]
ASSETS HELD FOR SALE
Operating properties	5,576
Accumulated depreciation	(79)
Operating real estate investments, net	5,497
Land held for development	0
Total real estate investments, net	5,497
Other assets	765
Total assets held for sale, net	6,262
LIABILITIES HELD FOR SALE
Other liabilities	387
Total liabilities held for sale	$ 387

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