Annual report pursuant to Section 13 and 15(d)

Significant Accounting Policies (Schedule Of Rental Property Improvements) (Details)

v3.20.4
Significant Accounting Policies (Schedule Of Rental Property Improvements) (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Property, Plant and Equipment [Line Items]    
Land held for development (including pre-development costs, if any) $ 364,946,000 $ 388,702,000
Development and construction in progress, including land 733,560,000 464,110,000
Total 1,098,506,000 852,812,000
Buildings and improvement 160,300,000 156,500,000
Development [Member]    
Property, Plant and Equipment [Line Items]    
Land 74,900,000 $ 96,600,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Development [Member]    
Property, Plant and Equipment [Line Items]    
Buildings and improvement 8,900,000  
Land $ 31,900,000