Acquisition, Development, and Disposition Activity Income from Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Property revenue		$ 2,179		$ 6,240
EXPENSES
Property operating and maintenance		955		2,906
Depreciation and amortization		499		1,170
Total expense		1,454		4,076
Operating income		725		2,164
Operating income, net of interest expense	0	725	0	2,164
Gain on disposition of properties		0		8,796
Income from discontinued operations		$ 725		$ 10,960