Annual report pursuant to Section 13 and 15(d)

Employee Benefit 401(k) Plans And Deferred Retirement Compensation Agreements (Details)

v2.4.1.9
Employee Benefit 401(k) Plans And Deferred Retirement Compensation Agreements (Details) (USD $)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Minimum employee subscription rate, percentage of compensation 1.00%cli_SavingsRetirementPlanEmployeeMinimumSubscriptionRate    
Maximum employee subscription rate, percentage of compensation 60.00%cli_SavingsRetirementPlanEmployeeMaximumSubscriptionRate    
Employee pre-tax contributions vested percentage 100.00%cli_EmployeePreTaxContributionsVestedPercent    
Vesting rate 20.00%cli_VestingRate    
Percentage vested after total service period 100.00%cli_PercentVestedAfterTotalServicePeriod    
Employees' vesting rights Participants are always 100 percent vested in their pre-tax contributions and will begin vesting in any matching or profit sharing contributions made on their behalf after two years of service with the Company at a rate of 20 percent per year, becoming 100 percent vested after a total of six years of service with the Company.    
Expenses for employee benefit plan $ 0us-gaap_EmployeeBenefitsAndShareBasedCompensation $ 117,000us-gaap_EmployeeBenefitsAndShareBasedCompensation $ 7,000us-gaap_EmployeeBenefitsAndShareBasedCompensation
Shares granted 376,719us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod [1],[2],[3] 168,841us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod [4],[5] 70,758us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod [6]
Shares issued for accrued dividends 966us-gaap_StockDividendsShares    
Period upon which stock units become payable following a triggering event 30 days    
Minimum [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Employer contribution vesting period 2 years    
Maximum [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Employer contribution vesting period 6 years    
Messr Lefkowitz And Messr Thomas [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Expenses for employee benefit plan 1,200,000us-gaap_EmployeeBenefitsAndShareBasedCompensation
/ us-gaap_TitleOfIndividualAxis
= cli_MessieurLefkowitzAndMessieurThomasMember 		   
Messr Hersh [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Amount of annual employer contribution to deferred retirement compensation 500,000cli_DefinedBenefitPlanAnnualEmployerContribution
/ us-gaap_TitleOfIndividualAxis
= cli_MessieurHershMember 		   
Deferred Retirement Compensation Units [Member]      
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]      
Expenses for employee benefit plan $ 2,957,000us-gaap_EmployeeBenefitsAndShareBasedCompensation
/ us-gaap_AwardTypeAxis
= cli_DeferredRetirementCompensationUnitsMember 		$ 595,000us-gaap_EmployeeBenefitsAndShareBasedCompensation
/ us-gaap_AwardTypeAxis
= cli_DeferredRetirementCompensationUnitsMember 		$ 0us-gaap_EmployeeBenefitsAndShareBasedCompensation
/ us-gaap_AwardTypeAxis
= cli_DeferredRetirementCompensationUnitsMember
Shares granted 36,347us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= cli_DeferredRetirementCompensationUnitsMember 		   
[1] Included in the 376,719 Restricted Stock Awards granted in 2014 were 8,211 awards granted to the Company’s two executive officers Anthony Krug and Gary Wagner.
[2] Includes 42,000 Performance Shares which were legally granted in 2013 for which the 2014 performance goals were set by the Committee on March 31, 2014. Also includes 87,734 shares which were additionally considered granted for accounting purposes to two executive officers in connection with their departure effective March 31, 2014, which vested on April 1, 2014.
[3] Includes 126,000 Performance Shares which were legally granted in 2013 for which future performance goals had not yet been set by the Committee. These awards were not considered granted for accounting purposes until these goals are set. These were considered granted in 2014 for accounting purposes in connection with the announcement of the departure of Mitchell E. Hersh in the fourth quarter 2014.
[4] Included in the 168,841 Restricted Stock Awards granted in 2013 were 106,933 awards granted to the Company’s four executive officers, Mitchell E. Hersh, Barry Lefkowitz, Roger W. Thomas and Anthony Krug.
[5] Includes 63,933 Performance Shares which were legally granted in 2013 for which the 2013 performance goals were not met, which may be earned if subsequent years’ performance goals are met.
[6] Included in the 70,758 Restricted Stock Awards granted in 2012 were 42,273 awards granted to the Company’s three executive officers, Mitchell E. Hersh, Barry Lefkowitz and Roger W. Thomas.