Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended
	May 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012
Summary Of Significant Accounting Policies [Line Items]
Percentage rents		$ 34,000	$ 32,000
Period of time from the date of development completion		1 year
Due from sale of land		2,500,000
Note receivable, interest rate		12.00%
Asset impairment charges					1,300,000
Impairment recovery of notes receivable	229,000			1,100,000
Proceeds from borrower of notes receivable	1,000,000	42,000
Allowance for uncollectible notes receivable		1,083,000	1,376,000	1,780,000		1,134,000
Minimum [Member] | Buildings [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life in years		39 years
Maximum [Member] | Buildings [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life in years		50 years
Maximum [Member] | Site Improvements [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life in years		20 years
Notes Receivable From Tenants [Member]
Summary Of Significant Accounting Policies [Line Items]
Notes receivables from various tenants		260,000
Allowance for uncollectible notes receivable		29,000				45,000
Bad debt expense		$ 10,000	$ 17,000