Discontinued Operations and Assets Held for Sale (Table Illustration of Discontinued Operations in Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Discontinued Operations
Revenues	$ 7	$ 29,709	$ 32,171	$ 89,112
Operating Expenses	(50)	(12,145)	(12,449)	(35,651)
Depreciation and amortization, discontinued operations	0	(9,228)	(3,517)	(28,335)
Operating Income (Loss)	(43)	8,336	16,205	25,126
Interest Expense	0	(6,059)	(5,659)	(18,557)
Income (loss) before gain on sales	(43)	2,277	10,546	6,569
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	66	564	417,795	22,864
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	23	2,841	428,341	29,433
Discontinued Operation, Tax Effect of Discontinued Operation	45	555	(3,175)	(2,969)
Income from discontinued operations	$ 68	$ 3,396	425,166	26,464
Payments For Second Generation Tenant Improvements Leasing Costs And Building Improvements			45,688	69,475
Discontinued Operations [Member]
Discontinued Operations
Payments For Second Generation Tenant Improvements Leasing Costs And Building Improvements			$ 7,400	$ 23,900