Investments In Unconsolidated Joint Ventures (Summary Of The Results Of Financial Position) (Details) (USD $)
In Thousands
Jun. 30, 2011
Dec. 31, 2010
Rental property, net $ 148,073 $ 152,372
Other assets 72,723 75,992
Total assets 220,796 228,364
Mortgages, loans payable and other obligations 143,425 146,731
Other liabilities 6,804 7,305
Partners'/members' capital (deficit) 70,567 74,328
Total liabilities and partners'/members' capital (deficit) 220,796 228,364
Company's investment in unconsolidated joint ventures, net 32,673 34,220
Plaza VIII & IX Associates [Member]
    
Rental property, net 8,641 8,947
Other assets 1,253 906
Total assets 9,894 9,853
Other liabilities 529 529
Partners'/members' capital (deficit) 9,365 9,324
Total liabilities and partners'/members' capital (deficit) 9,894 9,853
Company's investment in unconsolidated joint ventures, net 4,605 4,584
Harborside South Pier [Member]
    
Rental property, net 62,179 64,964
Other assets 13,428 11,681
Total assets 75,607 76,645
Mortgages, loans payable and other obligations 71,639 72,168
Other liabilities 5,044 4,356
Partners'/members' capital (deficit) (1,076) 121
Total liabilities and partners'/members' capital (deficit) 75,607 76,645
Company's investment in unconsolidated joint ventures, net 568 1,161
Red Bank Corporate Plaza [Member]
    
Rental property, net 23,214 23,594
Other assets 2,621 6,422
Total assets 25,835 30,016
Mortgages, loans payable and other obligations 18,520 20,424
Other liabilities 50 89
Partners'/members' capital (deficit) 7,265 9,503
Total liabilities and partners'/members' capital (deficit) 25,835 30,016
Company's investment in unconsolidated joint ventures, net 3,495 4,598
Gramercy Agreement [Member]
    
Rental property, net 39,732 40,786
Other assets 5,983 6,261
Total assets 45,715 47,047
Mortgages, loans payable and other obligations 50,978 50,978
Other liabilities 1,105 1,719
Partners'/members' capital (deficit) (6,368) (5,650)
Total liabilities and partners'/members' capital (deficit) 45,715 47,047
Princeton Forrestal Village [Member]
    
Other assets 196 1,435
Total assets 196 1,435
Other liabilities 76 612
Partners'/members' capital (deficit) 120 823
Total liabilities and partners'/members' capital (deficit) 196 1,435
Gale Kimball [Member]
    
Other assets 46 51
Total assets 46 51
Partners'/members' capital (deficit) 46 51
Total liabilities and partners'/members' capital (deficit) 46 51
12 Vreeland [Member]
    
Rental property, net 14,307 14,081
Other assets 497 734
Total assets 14,804 14,815
Mortgages, loans payable and other obligations 2,288 3,161
Partners'/members' capital (deficit) 12,516 11,654
Total liabilities and partners'/members' capital (deficit) 14,804 14,815
Company's investment in unconsolidated joint ventures, net 9,969 9,860
Boston-Downtown Crossing [Member]
    
Other assets 46,111 46,062
Total assets 46,111 46,062
Partners'/members' capital (deficit) 46,111 46,062
Total liabilities and partners'/members' capital (deficit) 46,111 46,062
Company's investment in unconsolidated joint ventures, net 12,998 13,022
Gale Jefferson [Member]
    
Other assets 2,588 2,440
Total assets 2,588 2,440
Partners'/members' capital (deficit) 2,588 2,440
Total liabilities and partners'/members' capital (deficit) 2,588 2,440
Company's investment in unconsolidated joint ventures, net $ 1,038 $ 995