Mortgage Loans Payable And Unsecured Credit Facilities (Schedule Of Debt Related To Continuing Operations) (Details) - USD ($)	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Mortgage loans payable	$ 299,022,000	$ 393,388,000	$ 516,292,000
Credit facilities	$ 78,000,000	$ 72,000,000
Continuing Operations [Member]
Debt Instrument [Line Items]
Weighted average interest rate	3.70%	4.30%
Total debt	$ 677,022,000	$ 665,388,000
Continuing Operations [Member] \| Fixed-Rate Mortgages [Member]
Debt Instrument [Line Items]
Mortgage loans payable	$ 299,022,000	$ 393,388,000
Weighted average interest rate	5.00%	5.40%
Interest rate, minimum	3.10%	3.10%
Interest rate, maximum	7.50%	7.50%
Continuing Operations [Member] \| Variable-Rate Mortgage [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Weighted average interest rate	1.70%	1.90%
Credit facilities	$ 78,000,000	$ 72,000,000
Continuing Operations [Member] \| Unsecured Credit Facility [Member] \| Term Loan Two [Member]
Debt Instrument [Line Items]
Weighted average interest rate	2.90%	3.20%
Credit facilities	$ 75,000,000	$ 75,000,000
Continuing Operations [Member] \| Unsecured Credit Facility [Member] \| Term Loan Three [Member]
Debt Instrument [Line Items]
Weighted average interest rate	2.80%
Credit facilities	$ 50,000,000
Continuing Operations [Member] \| Unsecured Credit Facility [Member] \| Term Loan Four [Member]
Debt Instrument [Line Items]
Weighted average interest rate	4.00%	4.10%
Credit facilities	$ 75,000,000	$ 75,000,000
Continuing Operations [Member] \| Unsecured Credit Facility [Member] \| Term Loan Five [Member]
Debt Instrument [Line Items]
Weighted average interest rate	3.30%
Credit facilities	$ 50,000,000
Continuing Operations [Member] \| Unsecured Credit Facility [Member] \| Variable-Rate Mortgage [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Weighted average interest rate	1.70%	1.90%
Credit facilities	$ 50,000,000	$ 50,000,000

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

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)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20
-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

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- Definition

When presenting a range of interest rates, the highest effective rate for funds borrowed under the debt agreement as of the balance sheet date.

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When presenting a range of interest rates, the lowest effective rate for funds borrowed under the debt agreement as of the balance sheet date.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

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- Definition

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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