Annual report pursuant to Section 13 and 15(d)

Organization And Basis Of Presentation (Narrative) (Details)

v3.19.3.a.u2
Organization And Basis Of Presentation (Narrative) (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2019
USD ($)
ft²
property
item
state
Dec. 19, 2019
ft²
Dec. 31, 2018
USD ($)
item
Real Estate Properties [Line Items]      
Percentage of ownership interest 90.40%   89.80%
Number of properties owned or investment interests 71    
Number of units | item 208   1,317
Number of states where properties are located | state 4    
Consolidated joint ventures, total real estate assets | $ $ 503.1   $ 480.4
Consolidated joint ventures, mortgages | $ 283.7   241.5
Consolidated joint ventures, other liabilities | $ $ 18.9   $ 23.0
Commercial Properties [Member]      
Real Estate Properties [Line Items]      
Number of tenants | item 400    
Multi-Family Properties [Member]      
Real Estate Properties [Line Items]      
Number of properties owned or investment interests 21    
Number of units | item 6,524    
Office [Member]      
Real Estate Properties [Line Items]      
Number of properties owned or investment interests 42    
Aggregate square feet of the property owned or investment interest | ft² 10,700,000    
Area of property (in square feet) | ft²   6,600,000  
Unconsolidated Joint Venture Office Buildings [Member]      
Real Estate Properties [Line Items]      
Number of properties owned or investment interests 2    
Aggregate square feet of the property owned or investment interest | ft² 200,000    
Area of property (in square feet) | ft² 200,000    
Unconsolidated Joint Venture Multi-Family Properties [Member]      
Real Estate Properties [Line Items]      
Number of properties owned or investment interests 7    
Number of units | item 2,611    
Unconsolidated Joint Venture Office/Flex Buildings And Hotel [Member]      
Real Estate Properties [Line Items]      
Number of properties owned or investment interests 3    
Number of units | item 723    
Parking/Retail [Member]      
Real Estate Properties [Line Items]      
Number of properties owned or investment interests 4    
Aggregate square feet of the property owned or investment interest | ft² 108,000    
Unconsolidated Joint Venture Parking/Retail Buildings [Member]      
Real Estate Properties [Line Items]      
Number of properties owned or investment interests 2    
Aggregate square feet of the property owned or investment interest | ft² 81,700    
Land [Member]      
Real Estate Properties [Line Items]      
Number of properties owned or investment interests 1