Annual report pursuant to Section 13 and 15(d)

Investments In Unconsolidated Joint Ventures (Narrative) (Details)

v3.8.0.1
Investments In Unconsolidated Joint Ventures (Narrative) (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
USD ($)
ft²
property
item
Dec. 31, 2016
USD ($)
Schedule of Equity Method Investments [Line Items]    
Company's net investment in unconsolidated joint ventures $ 252,626 $ 320,047
Amount outstanding 822,288 634,069
Management, leasing, development and other services fees 2,800 3,700
Accounts receivable due from unconsolidated joint ventures 800 $ 700
Maximum exposure to loss 165,500  
Estimated future funding commitments 36,000  
Property Debt, Balance $ 45,734  
Unconsolidated Joint Venture Office Buildings [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of properties | property 4  
Area of property (in square feet) | ft² 500,000  
Unconsolidated Joint Venture Retail Buildings [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of properties | property 2  
Area of mixed use project (in square feet) | ft² 81,700  
Unconsolidated Joint Venture Multi-Family Properties [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of properties | property 8  
Number of units | item 3,275  
Unconsolidated Joint Venture Hotel [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of units | item 350  
Unconsolidated Joint Venture Development Projects [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of units | item 419  
Unconsolidated Joint Venture Land Parcels [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of units | item 3,738  
Unconsolidated Joint Ventures [Member] | Guarantee of Indebtedness of Others [Member]    
Schedule of Equity Method Investments [Line Items]    
Maximum borrowing capacity $ 318,000  
Amount outstanding 200,100  
Unconsolidated Joint Ventures [Member] | Parent Company [Member] | Guarantee of Indebtedness of Others [Member]    
Schedule of Equity Method Investments [Line Items]    
Maximum borrowing capacity 36,000  
Amount outstanding $ 24,000  
Minimum [Member]    
Schedule of Equity Method Investments [Line Items]    
Percentage of interest in venture 12.50%  
Maximum [Member]    
Schedule of Equity Method Investments [Line Items]    
Percentage of interest in venture 85.00%  
Variable Interest Entity [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's net investment in unconsolidated joint ventures $ 129,500  
Number of VIEs | property 4