Mortgage Loans Payable And Unsecured Credit Facilities (Schedule Of Debt Related To Continuing Operations) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Mortgage loans payable	$ 138,243,000	$ 298,089,000
Credit facilities	72,000,000	78,000,000
Total debt gross	610,288,000
Unamortized premium	667,000
Unamortized debt issuance costs	(3,210,000)
Total debt	607,745,000
Term Loan [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs	(2,300,000)
Unsecured credit facility [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt gross	72,000,000
Unsecured credit facility [Member] \| Variable-Rate Mortgage [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facilities	$ 72,000,000	$ 78,000,000
Weighted average contractual interest rate	2.10%	1.70%
Continuing Operations [Member]
Debt Instrument [Line Items]
Weighted average contractual interest rate	3.30%	3.30%
Total debt gross	$ 610,288,000	$ 676,779,000
Unamortized premium	667,000	243,000
Unamortized debt issuance costs	(3,210,000)	(3,202,000)
Total debt	607,745,000	673,820,000
Continuing Operations [Member] \| Fixed-Rate Mortgages [Member]
Debt Instrument [Line Items]
Mortgage loans payable	$ 138,288,000	$ 298,779,000
Weighted average contractual interest rate	4.60%	5.40%
Continuing Operations [Member] \| Minimum [Member] \| Fixed-Rate Mortgages [Member]
Debt Instrument [Line Items]
Interest rate	3.90%	3.90%
Continuing Operations [Member] \| Maximum [Member] \| Fixed-Rate Mortgages [Member]
Debt Instrument [Line Items]
Interest rate	7.50%	7.50%
Continuing Operations [Member] \| Unsecured credit facility [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Two [Member]
Debt Instrument [Line Items]
Credit facilities	$ 75,000,000	$ 75,000,000
Weighted average contractual interest rate	2.90%	2.90%
Continuing Operations [Member] \| Unsecured credit facility [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Three [Member]
Debt Instrument [Line Items]
Credit facilities	$ 50,000,000	$ 50,000,000
Weighted average contractual interest rate	2.80%	2.80%
Continuing Operations [Member] \| Unsecured credit facility [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Four [Member]
Debt Instrument [Line Items]
Credit facilities	$ 75,000,000	$ 75,000,000
Weighted average contractual interest rate	4.00%	4.00%
Continuing Operations [Member] \| Unsecured credit facility [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Five [Member]
Debt Instrument [Line Items]
Credit facilities	$ 50,000,000	$ 50,000,000
Weighted average contractual interest rate	3.30%	3.30%
Continuing Operations [Member] \| Unsecured credit facility [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Six [Member]
Debt Instrument [Line Items]
Credit facilities	$ 100,000,000
Weighted average contractual interest rate	3.20%
Continuing Operations [Member] \| Unsecured credit facility [Member] \| Variable-Rate Mortgage [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Credit facilities	$ 50,000,000	$ 50,000,000
Weighted average contractual interest rate	2.10%	1.70%

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Amount, after accumulated amortization, of debt premium.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Weighted average interest rate of long-term debt outstanding.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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