Annual report pursuant to Section 13 and 15(d)

Real Estate Transactions (Schedule Of Purchase Price Allocation) (Details)

v2.4.1.9
Real Estate Transactions (Schedule Of Purchase Price Allocation) (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2014
Aug. 22, 2013
Business Acquisition [Line Items]      
Land 32,258us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand   $ 5,585us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
Buildings and improvements 195,258us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings    
Furniture, fixtures and equipment 3,290us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment    
Above market leases 24cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAboveMarketLeases    
In-place lease values 6,322cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases [1]    
Total assets acquired 237,152us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets    
Less: Below market lease values 593cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases [1]    
Non-controlling interest     1,252us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue
Total liabilities assumed 593us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities    
Net cash paid at acquisition 236,559us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet    
Maximum [Member]      
Business Acquisition [Line Items]      
Amortization period 1 year    
Andover Place [Member]      
Business Acquisition [Line Items]      
Land   8,535us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
/ us-gaap_BusinessAcquisitionAxis
= cli_AndoverPlaceMember 		 
Buildings and improvements   27,609us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings
/ us-gaap_BusinessAcquisitionAxis
= cli_AndoverPlaceMember 		 
Furniture, fixtures and equipment   459us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment
/ us-gaap_BusinessAcquisitionAxis
= cli_AndoverPlaceMember 		 
In-place lease values   1,118cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_AndoverPlaceMember 		[2]  
Total assets acquired   37,721us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= cli_AndoverPlaceMember 		 
Less: Below market lease values   25cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_AndoverPlaceMember 		[2]  
Net cash paid at acquisition   37,696us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= cli_AndoverPlaceMember 		 
Andover Place [Member] | Maximum [Member]      
Business Acquisition [Line Items]      
Amortization period   1 year  
Alterra At Overlook Ridge IA [Member]      
Business Acquisition [Line Items]      
Land 9,042us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIMember 		   
Buildings and improvements 50,671us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIMember 		   
Furniture, fixtures and equipment 801us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIMember 		   
In-place lease values 931cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIMember 		[1]    
Total assets acquired 61,445us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIMember 		   
Less: Below market lease values 195cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIMember 		[1]    
Total liabilities assumed 195us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIMember 		   
Net cash paid at acquisition 61,250us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIMember 		   
Alterra At Overlook Ridge IB [Member]      
Business Acquisition [Line Items]      
Land 12,055us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIBMember 		   
Buildings and improvements 71,409us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIBMember 		   
Furniture, fixtures and equipment 1,474us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIBMember 		   
In-place lease values 3,148cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIBMember 		[1]    
Total assets acquired 88,086us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIBMember 		   
Less: Below market lease values 136cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIBMember 		[1]    
Total liabilities assumed 136us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIBMember 		   
Net cash paid at acquisition 87,950us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= cli_AlterraAtOverlookRidgeIBMember 		   
Park Square [Member]      
Business Acquisition [Line Items]      
Land 4,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		   
Buildings and improvements 40,670us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		   
Furniture, fixtures and equipment 610us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		   
Above market leases 24cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAboveMarketLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		   
In-place lease values 1,249cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		[1]    
Total assets acquired 46,553us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		   
Less: Below market lease values 177cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		[1]    
Total liabilities assumed 177us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		   
Net cash paid at acquisition 46,376us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= cli_ParkSquareMember 		   
Richmond Court [Member]      
Business Acquisition [Line Items]      
Land 2,992us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
/ us-gaap_BusinessAcquisitionAxis
= cli_RichmondCourtMember 		   
Buildings and improvements 13,534us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings
/ us-gaap_BusinessAcquisitionAxis
= cli_RichmondCourtMember 		   
Furniture, fixtures and equipment 177us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment
/ us-gaap_BusinessAcquisitionAxis
= cli_RichmondCourtMember 		   
In-place lease values 356cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_RichmondCourtMember 		[1]    
Total assets acquired 17,059us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= cli_RichmondCourtMember 		   
Less: Below market lease values 36cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_RichmondCourtMember 		[1]    
Total liabilities assumed 36us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
/ us-gaap_BusinessAcquisitionAxis
= cli_RichmondCourtMember 		   
Net cash paid at acquisition 17,023us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= cli_RichmondCourtMember 		   
Riverwatch Commons [Member]      
Business Acquisition [Line Items]      
Land 4,169us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
/ us-gaap_BusinessAcquisitionAxis
= cli_RiverwatchCommonsMember 		   
Buildings and improvements 18,974us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBuildings
/ us-gaap_BusinessAcquisitionAxis
= cli_RiverwatchCommonsMember 		   
Furniture, fixtures and equipment 228us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEquipment
/ us-gaap_BusinessAcquisitionAxis
= cli_RiverwatchCommonsMember 		   
In-place lease values 638cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInPlaceLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_RiverwatchCommonsMember 		[1]    
Total assets acquired 24,009us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= cli_RiverwatchCommonsMember 		   
Less: Below market lease values 49cli_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBelowMarketLeases
/ us-gaap_BusinessAcquisitionAxis
= cli_RiverwatchCommonsMember 		[1]    
Total liabilities assumed 49us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
/ us-gaap_BusinessAcquisitionAxis
= cli_RiverwatchCommonsMember 		   
Net cash paid at acquisition 23,960us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= cli_RiverwatchCommonsMember 		   
[1] In-place lease values and above/below market lease values will be amortized over one year or less.
[2] In-place lease values and below market lease values will be amortized over one year or less.