Quarterly report pursuant to Section 13 or 15(d)

Redeemable Noncontrolling Interests (Narrative) (Details)

v3.21.2
Redeemable Noncontrolling Interests (Narrative) (Details)
 3 Months Ended 9 Months Ended 12 Months Ended
Jun. 30, 2019
USD ($)
Jun. 28, 2019
USD ($)
Jun. 26, 2019
USD ($)
item
property
Mar. 10, 2017
USD ($)
Feb. 28, 2017
USD ($)
$ / shares
shares
Feb. 27, 2017
USD ($)
Feb. 03, 2017
USD ($)
$ / shares
shares
Sep. 30, 2021
USD ($)
$ / shares
Sep. 30, 2020
USD ($)
$ / shares
Mar. 31, 2019
USD ($)
Sep. 30, 2021
USD ($)
$ / shares
Sep. 30, 2020
USD ($)
$ / shares
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Jun. 25, 2019
item
Apr. 30, 2017
shares
Redeemable Noncontrolling Interest [Line Items]                                
General and administrative               $ 11,292,000 $ 26,361,000   $ 43,347,000 $ 59,423,000        
Payment for borrowings                     $ 37,000,000 364,000,000        
Minimum [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Percentage of interest in venture               20.00%     20.00%          
Maximum [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Percentage of interest in venture               85.00%     85.00%          
Mack-Cali Realty LP [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
General and administrative               $ 11,292,000 $ 26,361,000   $ 43,347,000 $ 59,423,000        
Common unit distribution per unit declared | $ / shares               $ 0 $ 0   $ 0 $ 0.40        
Payment for borrowings                     $ 37,000,000 $ 364,000,000        
RRT [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Number Of Board Members | item     7                       6  
RRT [Member] | Designated By Mack Cali [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Number Of Board Members | item     5                          
RRT [Member] | Designated By Rockpoint [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Number Of Board Members | item     2                          
Series A Units [Member] | Mack-Cali Realty LP [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Preferred units shares issued | shares             42,800                  
Preferred unit annual rate             3.50%                  
Percentage of interest in venture             37.50%                  
Preferred unit in operating partnership             $ 1,000                  
Convertible preferred units | shares             28.15                  
Expiration period             5 years                  
Shares that may be converted to common units | shares             1,204,820                  
Common unit distribution per unit declared | $ / shares             $ 35.52                  
Series A-1 Units [Member] | Mack-Cali Realty LP [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Preferred units shares issued | shares         9,213                     91
Preferred unit annual rate         3.50%                      
Percentage of interest in venture         13.80%                      
Preferred unit in operating partnership         $ 1,000                      
Convertible preferred units | shares         27.936                      
Expiration period         5 years           5 years          
Shares that may be converted to common units | shares         257,375                      
Common unit distribution per unit declared | $ / shares         $ 35.80                      
Monaco (BLVD 495 N/S) [Member] | Series A-1 Units [Member] | Mack-Cali Realty LP [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Preferred units shares issued | shares         9,122                      
Investment Agreement [Member] | Minimum [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Incremental closing payments, Limited Partnership interest                           $ 105,000,000    
RRLP [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Annual return on the equity value                     6.00%          
RRLP [Member] | Investment Agreement [Member] | Cash Flow From Capital Events, Distribution Four [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Capital base return                     5.00%          
RRLP [Member] | Credit Enhancement Note [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Maximum borrowing capacity               $ 50,000,000     $ 50,000,000          
Increased line of credit               25,000,000     $ 25,000,000          
Spread over LIBOR                     50.00%          
Rockpoint [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Estimated redemption value                     $ 466,300,000          
Rockpoint [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Invested capital               400,000,000     400,000,000          
Rockpoint [Member] | Cash Flow From Capital Events, Distribution Five [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Invested capital               400,000,000     400,000,000          
Rockpoint [Member] | Cash Flow From Capital Events, Distribution Six [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Invested capital               $ 400,000,000     $ 400,000,000          
Rockpoint [Member] | Distribution One [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Purchase price   $ 173,500,000                            
Purchase price, less distributions   198,500,000                            
Rockpoint [Member] | Distribution Two [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Purchase price, less distributions   $ 1,500,000                            
Rockpoint [Member] | Preferred Units [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     10.947%          
Rockpoint [Member] | Preferred Units [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     21.89%          
Rockpoint [Member] | Preferred Units [Member] | Cash Flow From Capital Events, Distribution Five [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     21.89%          
Rockpoint [Member] | Investment Agreement [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Contributed equity value       $ 1,230,000,000                        
Incremental closing payments, Limited Partnership interest     $ 46,000,000 $ 150,000,000           $ 45,000,000            
Rockpoint [Member] | Investment Agreement [Member] | Maximum [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Contributed amount to obtain equity units           $ 300,000,000                    
Rockpoint [Member] | Add On Investment Agreement [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Contributed amount to obtain equity units     $ 100,000,000                          
Number of properties in which additional interest was acquired during period | property     2                          
Right of first refusal to invest                     $ 100,000,000          
General and administrative                         $ 371,000      
Payment for borrowings $ 100,000,000                              
Rockpoint [Member] | Add On Investment Agreement [Member] | Maximum [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Contributed amount to obtain equity units                     $ 154,000,000          
Rockpoint [Member] | RRLP [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Annual return                     6.00%          
Base return                     4.64%          
Rockpoint [Member] | RRLP [Member] | Cash Flow From Capital Events, Distribution Three [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Base return                     4.64%          
Rockpoint [Member] | RRLP [Member] | Cash Flow From Capital Events, Distribution Four [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Capital base return                     4.64%          
Rockpoint [Member] | RRLP [Member] | Cash Flow From Capital Events, Distribution Five [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Internal rate of return                     11.00%          
Rockpoint [Member] | RRLP [Member] | Cash Flow From Capital Events, Distribution Six [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata share                     50.00%          
Rockpoint [Member] | RRLP [Member] | Investment Agreement [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Base return                     5.00%          
Rockpoint [Member] | RRLP [Member] | Investment Agreement [Member] | Cash Flow From Capital Events, Distribution Three [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Base return                     95.00%          
RRT [Member] | Preferred Units [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     2.65%          
RRT [Member] | Preferred Units [Member] | Cash Flow From Capital Events, Distribution Five [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     2.65%          
RRT [Member] | Preferred Units [Member] | Cash Flow From Capital Events, Distribution Six [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     1.325%          
RRT [Member] | Common Units [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     75.46%          
RRT [Member] | Common Units [Member] | Cash Flow From Capital Events, Distribution Five [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     75.46%          
RRT [Member] | Common Units [Member] | Cash Flow From Capital Events, Distribution Six [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Pro rata distribution                     87.728%          
RRT [Member] | RRLP [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Loan-to-value ratio     65.00%                          
Equity capitalization percent                     10.00%          
RRT [Member] | RRLP [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Base return                     95.36%          
RRT [Member] | RRLP [Member] | Cash Flow From Capital Events, Distribution Three [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Base return                     95.36%          
RRT [Member] | RRLP [Member] | Cash Flow From Capital Events, Distribution Four [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Capital base return                     95.36%          
RRT [Member] | RRLP [Member] | Investment Agreement [Member] | Cash Flow From Operations [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Base return                     95.00%          
RRT [Member] | RRLP [Member] | Investment Agreement [Member] | Cash Flow From Capital Events, Distribution Three [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Base return                     5.00%          
RRT [Member] | RRLP [Member] | Investment Agreement [Member] | Cash Flow From Capital Events, Distribution Four [Member]                                
Redeemable Noncontrolling Interest [Line Items]                                
Capital base return                     95.00%