Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Significant Accounting Policies (Schedule Of Rental Property Improvements) (Details) - USD ($)
$ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2018
Dec. 31, 2017
Property, Plant and Equipment [Line Items]    
Land held for development (including pre-development costs, if any) $ 508,342 $ 483,432
Development and construction in progress, including land 405,853 535,971
Total 914,195 1,019,403
Buildings and improvement 220,700 188,100
Development [Member]    
Property, Plant and Equipment [Line Items]    
Land $ 49,600 $ 77,000