Segment Reporting (Schedule Of Selected Results Of Operations And Asset Information) (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Segment Reporting Information [Line Items]          
Total revenues $ 83,744 $ 79,197 $ 241,084 $ 236,999  
Total operating and interest expenses 70,970 86,223 212,190 228,528  
Equity in earnings (loss) of unconsolidated joint ventures (1,724) 1,373 (2,831) (281)  
Net operating income (loss) 11,050 (5,653) 26,063 8,190  
Total assets 4,567,167   4,567,167   $ 5,147,786
Total long-lived assets 4,211,463   4,211,463   4,727,128
Total investments in unconsolidated joint ventures 148,507   148,507   162,382
Commercial And Other Real Estate [Member]          
Segment Reporting Information [Line Items]          
Total revenues 38,978 39,835 119,690 117,239  
Total operating and interest expenses 15,252 16,922 47,679 55,171  
Equity in earnings (loss) of unconsolidated joint ventures 22 493 (111) (1)  
Net operating income (loss) 23,748 23,406 71,900 62,067  
Total assets 1,237,667   1,237,667   1,881,161
Total long-lived assets 1,101,074   1,101,074   1,693,054
Total investments in unconsolidated joint ventures         5,555
Multiple-Family Real Estate & Services [Member]          
Segment Reporting Information [Line Items]          
Total revenues 45,182 37,658 122,778 118,739  
Total operating and interest expenses 27,770 26,772 80,835 71,689  
Equity in earnings (loss) of unconsolidated joint ventures (1,746) 880 (2,720) (280)  
Net operating income (loss) 15,666 11,766 39,223 46,770  
Total assets 3,317,079   3,317,079   3,249,516
Total long-lived assets 3,112,054   3,112,054   3,035,485
Total investments in unconsolidated joint ventures 148,507   148,507   156,827
Corporate & Other [Member]          
Segment Reporting Information [Line Items]          
Total revenues (416) 1,704 (1,384) 1,021  
Total operating and interest expenses 27,948 42,529 83,676 101,668  
Net operating income (loss) (28,364) $ (40,825) (85,060) $ (100,647)  
Total assets 12,421   12,421   17,109
Total long-lived assets $ (1,665)   $ (1,665)   $ (1,411)