Annual report pursuant to Section 13 and 15(d)

Organization And Basis Of Presentation (Details)

v3.3.1.900
Organization And Basis Of Presentation (Details)
$ in Millions
12 Months Ended
Dec. 31, 2015
USD ($)
ft²
state
property
item
Dec. 31, 2014
USD ($)
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 275  
Aggregate square feet of the property owned or investment interest | ft² 29,900,000  
Number of states where properties are located | state 7  
Consolidated joint ventures, total real estate assets | $ $ 273.4 $ 242.9
Consolidated joint ventures, mortgages | $ 89.5 94.3
Consolidated joint ventures, other liabilities | $ $ 17.5 $ 15.7
Commercial Properties [Member]    
Real Estate Properties [Line Items]    
Number of tenants | item 1,900  
Multi-Family Properties [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 19  
Number of units | item 5,644  
Office [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 147  
Aggregate square feet of the property owned or investment interest | ft² 24,600,000  
Office Flex Buildings [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 94  
Aggregate square feet of the property owned or investment interest | ft² 4,800,000  
Flex Properties [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 109  
Unconsolidated Joint Venture Office Buildings [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 36  
Aggregate square feet of the property owned or investment interest | ft² 5,600,000  
Unconsolidated Joint Venture Multi-Family Properties [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 13  
Number of units | item 4,343  
Unconsolidated Joint Venture Office/Flex Buildings And Hotel [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 1  
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  
Unconsolidated Joint Venture Hotel [Member]    
Real Estate Properties [Line Items]    
Number of units | item 350  
Office Flex And Industrial Warehouse Facilities [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 6  
Aggregate square feet of the property owned or investment interest | ft² 387,400  
Office Flex And Parking/Retail [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 5  
Aggregate square feet of the property owned or investment interest | ft² 121,700  
Office Flex And Land [Member]    
Real Estate Properties [Line Items]    
Number of properties owned or investment interests 3