Annual report pursuant to Section 13 and 15(d)

Unsecured Revolving Credit Facility And Term Loans (Schedule Of Interest Rate On Outstanding Borrowings Payable) (Details)

v3.8.0.1
Unsecured Revolving Credit Facility And Term Loans (Schedule Of Interest Rate On Outstanding Borrowings Payable) (Details) - 2016 Term Loan [Member]
 12 Months Ended
Dec. 31, 2017
Line of Credit Facility [Line Items]  
Interest Rate - Applicable Basis Points Above LIBOR 1.40%
Mack-Cali Realty LP [Member] | No Ratings Or Less Than Baa3 [Member] | No Ratings Or Less Than BBB- [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings No ratings or less than BBB-/Baa3
Interest Rate - Applicable Basis Points Above LIBOR 1.85%
Mack-Cali Realty LP [Member] | Baa3 [Member] | BBB- [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB- or Baa3 (current interest rate based on Company's election)
Interest Rate - Applicable Basis Points Above LIBOR 1.40%
Mack-Cali Realty LP [Member] | Baa2 [Member] | BBB [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB or Baa2
Interest Rate - Applicable Basis Points Above LIBOR 1.15%
Mack-Cali Realty LP [Member] | Baa1 [Member] | BBB+ [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings BBB+ or Baa1
Interest Rate - Applicable Basis Points Above LIBOR 1.00%
Mack-Cali Realty LP [Member] | A3 Or Higher [Member] | A- Or Higher [Member]  
Line of Credit Facility [Line Items]  
Unsecured Debt Ratings A- or A3 or higher
Interest Rate - Applicable Basis Points Above LIBOR 0.90%