Annual report pursuant to Section 13 and 15(d)

Deferred Charges, Goodwill And Other Assets (Summary Of Scheduled Amortization) (Details)

v2.4.1.9
Deferred Charges, Goodwill And Other Assets (Summary Of Scheduled Amortization) (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]      
2015 $ 226,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths    
2016 82,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo    
2017 103,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree    
2018 77,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour    
2019 (53,000)us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive    
Acquired Above-Market Lease Intangibles [Member]      
Finite-Lived Intangible Assets [Line Items]      
2015 (338,000)us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_AboveMarketLeasesMember
   
2016 (288,000)us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_AboveMarketLeasesMember
   
2017 (261,000)us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_AboveMarketLeasesMember
   
2018 (233,000)us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_AboveMarketLeasesMember
   
2019 (209,000)us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_AboveMarketLeasesMember
   
Acquired Below-Market Lease Intangibles [Member]      
Finite-Lived Intangible Assets [Line Items]      
2015 564,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= cli_BelowMarketLeaseIntangiblesMember
   
2016 370,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= cli_BelowMarketLeaseIntangiblesMember
   
2017 364,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= cli_BelowMarketLeaseIntangiblesMember
   
2018 310,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= cli_BelowMarketLeaseIntangiblesMember
   
2019 156,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= cli_BelowMarketLeaseIntangiblesMember
   
In-Place Leases [Member]      
Finite-Lived Intangible Assets [Line Items]      
2015 1,231,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeasesAcquiredInPlaceMember
   
2016 1,224,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeasesAcquiredInPlaceMember
   
2017 918,000us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeasesAcquiredInPlaceMember
   
Amortization expense $ 6,900,000us-gaap_AmortizationOfIntangibleAssets
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeasesAcquiredInPlaceMember
$ 10,700,000us-gaap_AmortizationOfIntangibleAssets
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeasesAcquiredInPlaceMember
$ 10,200,000us-gaap_AmortizationOfIntangibleAssets
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeasesAcquiredInPlaceMember