Discontinued Operations and Assets Held for Sale (Table Illustration of Discontinued Operations in Income Statement) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Discontinued Operations
Revenues	$ 32,115	$ 30,072
Operating Expenses	(12,386)	(12,403)
Depreciation and amortization, discontinued operations	(3,517)	(9,966)
Operating Income (Loss)	16,212	7,703
Interest Expense	(6,034)	(6,378)
Income (loss) before gain on sales	10,178	1,325
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	28,553	21,077
Discontinued Operation, Tax Effect of Discontinued Operation	0	(2,977)
Income (loss) from discontinued operations	28,553	18,100
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	18,375	19,752
Payments For Second Generation Tenant Improvements Leasing Costs And Building Improvements	17,496	19,631
Discontinued Operations [Member]
Discontinued Operations
Payments For Second Generation Tenant Improvements Leasing Costs And Building Improvements	8,600	3,800
Medical Office [Member]
Discontinued Operations
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	$ 1,252