Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) segment shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2013 USD ($) shares
Property, Plant and Equipment [Line Items]
Allowance for uncollectible accounts	$ 400,000	$ 400,000
Allowance for uncollectable deferred rent receivables	$ 909,000	841,000
Cash and cash equivalents maximum benchmark (in months)	3 months
Minimum expenditure costs subject to capitalization and depreciation	$ 2,000
Minimum expected future benefit period on expenditures cost to be capitalized and depreciated (in years)	2 years
Minimum transaction cost subject to capitalization and depreciation	$ 1,000
Minimum expected future benefit period on transaction cost to be capitalized and depreciated (in years)	1 year
Maximum transaction costs subject to being expensed as incurred	$ 1,000
Maximum length of lease period for transaction costs to be expensed as incurred	1 year
Length of time criteria for expected sale of assets to be classified as properties held for disposition	12 months
Increase (decrease) in rental income due to amortization of net intangible assets or liabilities	$ 1,251,000	901,000	$ (118,000)
Value of in-place leases resulting in a net intangible asset	1,700,000	2,500,000
Accumulated amortization - intangible assets	$ 8,600,000	7,800,000
Intangible assets, weighted average amortization period (in years)	8 years 8 months 12 days
Value of in-place leases resulting in a net intangible liability	$ 1,800,000	3,900,000
Accumulated amortization - intangible liabilities	$ 9,000,000	$ 6,900,000
Intangible liability, weighted average amortization period (in years)	5 years 4 months 24 days
Distribution of taxable income requirement	90.00%
Income tax provision	$ 0
Odds of a particular tax position will be sustained upon examination or audit	50.00%
Anti-dilutive share options to purchase | shares	32,000	16,000	14,000
Number of operating segments | segment	1
Maximum [Member] | Building And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	30 years
Minimum [Member] | Building And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	5 years