Debt instrument maturity year range end.

No definition available.

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Namespace Prefix:	cdr_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument maturity year range start.

+ References

No definition available.

+ Details

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Namespace Prefix:	cdr_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

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 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 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

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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.

+ References

Reference 1: 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(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: 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 3: 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

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ 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 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=cdr_TermLoanTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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- Details

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- Details

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- Details

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Mortgage Loans Payable and Credit Facility (Schedule of Debt Related to Continuing Operations) (Details) - USD ($)		9 Months Ended
	Sep. 08, 2017	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Mortgage loans payable		$ 135,815,000	$ 138,243,000
Unsecured revolving credit facility		95,000,000	$ 72,000,000
Term Loan Two [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date	Feb. 28, 2021
Unsecured revolving credit facility	$ 75,000,000
Term Loan Three [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date	Feb. 28, 2022
Unsecured revolving credit facility	$ 50,000,000
Term Loan Four [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date	Sep. 30, 2022
Unsecured revolving credit facility	$ 50,000,000
Term Loan Six [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date	Sep. 30, 2024
Unsecured revolving credit facility	$ 75,000,000
Continuing Operations [Member]
Debt Instrument [Line Items]
Total debt gross		630,888,000
Unamortized premium		570,000
Unamortized debt issuance costs		(3,788,000)
Total debt		$ 627,670,000
Weighted average contractual interest rate		3.40%
Continuing Operations [Member] \| Fixed-Rate Mortgages [Member]
Debt Instrument [Line Items]
Maturity date range, start		2021
Maturity date range, end		2029
Mortgage loans payable		$ 135,888,000
Weighted average contractual interest rate		4.60%
Continuing Operations [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Two [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date		Feb. 28, 2021
Unsecured revolving credit facility		$ 75,000,000
Weighted average contractual interest rate		3.60%
Continuing Operations [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Three [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date		Feb. 28, 2022
Unsecured revolving credit facility		$ 50,000,000
Weighted average contractual interest rate		3.00%
Continuing Operations [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Four [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date		Sep. 30, 2022
Unsecured revolving credit facility		$ 50,000,000
Weighted average contractual interest rate		2.80%
Continuing Operations [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Five [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date		Apr. 30, 2023
Unsecured revolving credit facility		$ 100,000,000
Weighted average contractual interest rate		3.20%
Continuing Operations [Member] \| Fixed-Rate Mortgages [Member] \| Term Loan Six [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date		Sep. 30, 2024
Unsecured revolving credit facility		$ 75,000,000
Weighted average contractual interest rate		3.30%
Continuing Operations [Member] \| Variable-Rate Mortgage [Member] \| Revolving Credit Facility [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date		Sep. 30, 2021
Unsecured revolving credit facility		$ 95,000,000
Weighted average contractual interest rate		2.70%
Continuing Operations [Member] \| Variable-Rate Mortgage [Member] \| Term Loan [Member] \| Unsecured credit facility [Member]
Debt Instrument [Line Items]
Maturity date		Sep. 30, 2022
Unsecured revolving credit facility		$ 50,000,000
Weighted average contractual interest rate		2.60%