Property Transactions (Components of Income (Loss) from Discontinued Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Document Fiscal Year Focus	2015	2014	2013
Components of Income (Loss) from Discontinued Operations
Income (loss) from discontinued operations	$ (35)	$ 1,800	$ 3,299
Gain (loss) on sale from discontinued operations	(551)	19,358	11,489
Discontinued Operations [Member]
Components of Income (Loss) from Discontinued Operations
Rental property revenues	4	2,927	10,552
Other revenues	6	29	40
Third party management and leasing revenues	0	0	76
Third party management and leasing expenses	0	0	(99)
Depreciation and amortization	0	0	(3,083)
Rental property operating expenses	(27)	(28)	(25)
Rental property operating expenses	(18)	(1,128)	(4,162)
Income (loss) from discontinued operations	$ (35)	$ 1,800	$ 3,299