Real Estate Investments - Discontinued Operations and Assets Held for Sale - Income Statement (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Revenues
Real Estate Revenue, Net	$ 87,829	$ 75,880
Revenues	91,899	80,273
Expenses
Property operating	33,431	29,452
General and administrative	5,978	6,540
Depreciation	24,134	21,180
Amortization	2,759	2,666
Total Expenses	66,349	59,826
Other Income (Expense)
Interest expense	(17,918)	(19,771)
Interest and other income, net	100	231
Total other income (expense)	(17,818)	(19,540)
Discontinued Operations
Income from discontinued operations	(344)	1,705
Impairments	3,425	3,630
INCOME (LOSS) FROM DISCONTINUED OPERATIONS	(3,769)	(1,925)
Discontinued Operations [Member]
Revenues
Real Estate Revenue, Net	258	3,163
Revenues	258	3,163
Expenses
Property operating	512	689
General and administrative	2	2
Depreciation	88	721
Amortization	0	23
Total Expenses	602	1,435
Other Income (Expense)
Interest expense	0	(24)
Interest and other income, net	0	1
Total other income (expense)	0	(23)
Discontinued Operations
Income from discontinued operations	(344)	1,705
Impairments	(3,425)	(3,630)
INCOME (LOSS) FROM DISCONTINUED OPERATIONS	$ (3,769)	$ (1,925)