Discontinued Operations and Assets Held for Sale (Table Illustration of Discontinued Operations in Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Discontinued Operations
Revenues	$ 229	$ 32,115
Operating Expenses	8	(12,386)
Depreciation and amortization, discontinued operations	0	(3,517)
Operating Income (Loss)	237	16,212
Interest Expense	0	(6,034)
Income before gain on sales	237	10,178
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	(86)	18,375
Income from discontinued operations	151	28,553
Payments For Second Generation Tenant Improvements Leasing Costs And Building Improvements	$ 14,401	17,496
Discontinued Operations [Member]
Discontinued Operations
Payments For Second Generation Tenant Improvements Leasing Costs And Building Improvements		$ 8,600