Annual report pursuant to Section 13 and 15(d)

Mack-Cali Realty Corporation Stockholders' Equity (Stock Options Plans) (Narrative) (Details)

v2.4.1.9
Mack-Cali Realty Corporation Stockholders' Equity (Stock Options Plans) (Narrative) (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
May 31, 2013
May 31, 2004
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock option terms 10 years        
Weighted average remaining contractual life 4 years 10 months 24 days 8 months 12 days      
Share price $ 1.71us-gaap_SharePrice        
Proceeds from stock options exercised $ 0us-gaap_ProceedsFromStockOptionsExercised $ 0us-gaap_ProceedsFromStockOptionsExercised $ 0us-gaap_ProceedsFromStockOptionsExercised    
Stock options expense $ 4,000us-gaap_StockOptionPlanExpense $ 0us-gaap_StockOptionPlanExpense $ 0us-gaap_StockOptionPlanExpense    
2013 Incentive Stock Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reserved stocks for issuance       4,600,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= cli_TwoThousandThirteenIncentiveStockPlanMember
 
2004 Incentive Stock Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reserved stocks for issuance         2,500,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= cli_TwoThousandFourIncentiveStockPlanMember
Shares issued 0us-gaap_CommonStockSharesIssued
/ us-gaap_PlanNameAxis
= cli_TwoThousandFourIncentiveStockPlanMember
       
Employee And Director Plan [Member] | Minimum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reserved stocks for issuance 2,700,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= cli_EmployeeAndDirectorPlanMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
       
Employee And Director Plan [Member] | Maximum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reserved stocks for issuance 4,350,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= cli_EmployeeAndDirectorPlanMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
       
2000 Employee Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Exercisable time period 5 years        
2000 Employee Plan [Member] | Minimum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reserved stocks for issuance 2,500,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= cli_TwoThousandEmployeePlanMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
       
2000 Employee Plan [Member] | Maximum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reserved stocks for issuance 4,000,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= cli_TwoThousandEmployeePlanMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
       
2000 Director Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Exercisable time period 1 year        
2000 Director Plan [Member] | Minimum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reserved stocks for issuance 200,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= cli_TwoThousandDirectorPlanMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
       
2000 Director Plan [Member] | Maximum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reserved stocks for issuance 350,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= cli_TwoThousandDirectorPlanMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember