Summary of Significant Accounting Policies (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2011 Y D counts
Revenue Recognition
Maximum period over which loan is to be considered as non-performing (in days)	60
Maximum period over which a lease is to be considered as non-performing (in days)	60
Methods used for calculation of annual increases over the rents of the prior year	4
Specified annual increase over the prior year's rent, low end of range (as a percent)	2.00%
Specified annual increase over the prior year's rent, high end of range (as a percent)	3.00%
Federal Income Taxes
Period considered for calculation of depreciation for federal tax purpose (in years)	27.5
Period considered for determining the taxability of distributions to shareholders (in years)	40
Excess of book basis of net depreciable assets over tax basis	$ 85,100,000
Discontinued Operations
Maximum period within which sale of property is probable (in years)	1