Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Expense (Benefit) [Abstract]
Annual dividends distribution percentage to shareholders to qualify as a REIT	90.00%
Income tax related to gain on sale of available-for-sale investments		$ 1,000,000
Significant temporary differences or tax credits associated with our taxable REIT subsidiaries	0
Operating Loss Carryforwards	30,200,000
Statement [Line Items]
Difference Between Carry Value Of Net Assets And Tax Basis Of Net Assets	953,700,000
Income tax expense	1,208,000	2,220,000	1,581,000
Uncertain tax positions or unrecognized tax benefits	$ 0
Minimum [Member]
Statement [Line Items]
Operating Loss Carryforwards, Expiration Dates	2019
Maximum [Member]
Statement [Line Items]
Operating Loss Carryforwards, Expiration Dates	2032