Investments In Unconsolidated Joint Ventures (Summary Of The Results Of Financial Position) (Details) (USD $)
In Thousands | Sep. 30, 2011 | Dec. 31, 2010 |
|---|
| Rental property, net | $ 145,438 | $ 152,372 |
| Other assets | 70,871 | 76,041 |
| Total assets | 216,309 | 228,413 |
| Mortgages, loans payable and other obligations | 141,974 | 146,731 |
| Other liabilities | 6,592 | 7,305 |
| Partners'/members' capital (deficit) | 67,743 | 74,377 |
| Total liabilities and partners'/members' capital (deficit) | 216,309 | 228,413 |
| Company's investment in unconsolidated joint ventures, net | 31,991 | 34,220 |
Plaza VIII & IX Associates [Member] | | |
| Rental property, net | 8,488 | 8,947 |
| Other assets | 746 | 906 |
| Total assets | 9,234 | 9,853 |
| Other liabilities | 532 | 529 |
| Partners'/members' capital (deficit) | 8,702 | 9,324 |
| Total liabilities and partners'/members' capital (deficit) | 9,234 | 9,853 |
| Company's investment in unconsolidated joint ventures, net | 4,273 | 4,584 |
Harborside South Pier [Member] | | |
| Rental property, net | 60,937 | 64,964 |
| Other assets | 12,430 | 11,681 |
| Total assets | 73,367 | 76,645 |
| Mortgages, loans payable and other obligations | 70,964 | 72,168 |
| Other liabilities | 4,745 | 4,356 |
| Partners'/members' capital (deficit) | (2,342) | 121 |
| Total liabilities and partners'/members' capital (deficit) | 73,367 | 76,645 |
| Company's investment in unconsolidated joint ventures, net | (70) | 1,161 |
Red Bank Corporate Plaza [Member] | | |
| Rental property, net | 23,020 | 23,594 |
| Other assets | 2,791 | 6,422 |
| Total assets | 25,811 | 30,016 |
| Mortgages, loans payable and other obligations | 18,280 | 20,424 |
| Other liabilities | 58 | 89 |
| Partners'/members' capital (deficit) | 7,473 | 9,503 |
| Total liabilities and partners'/members' capital (deficit) | 25,811 | 30,016 |
| Company's investment in unconsolidated joint ventures, net | 3,607 | 4,598 |
Gramercy Agreement [Member] | | |
| Rental property, net | 39,578 | 40,786 |
| Other assets | 5,767 | 6,261 |
| Total assets | 45,345 | 47,047 |
| Mortgages, loans payable and other obligations | 50,978 | 50,978 |
| Other liabilities | 1,196 | 1,719 |
| Partners'/members' capital (deficit) | (6,829) | (5,650) |
| Total liabilities and partners'/members' capital (deficit) | 45,345 | 47,047 |
Princeton Forrestal Village [Member] | | |
| Other assets | 181 | 1,435 |
| Total assets | 181 | 1,435 |
| Other liabilities | 61 | 612 |
| Partners'/members' capital (deficit) | 120 | 823 |
| Total liabilities and partners'/members' capital (deficit) | 181 | 1,435 |
Gale Kimball [Member] | | |
| Other assets | 44 | 51 |
| Total assets | 44 | 51 |
| Partners'/members' capital (deficit) | 44 | 51 |
| Total liabilities and partners'/members' capital (deficit) | 44 | 51 |
12 Vreeland [Member] | | |
| Rental property, net | 13,415 | 14,081 |
| Other assets | 175 | 734 |
| Total assets | 13,590 | 14,815 |
| Mortgages, loans payable and other obligations | 1,752 | 3,161 |
| Partners'/members' capital (deficit) | 11,838 | 11,654 |
| Total liabilities and partners'/members' capital (deficit) | 13,590 | 14,815 |
| Company's investment in unconsolidated joint ventures, net | 10,103 | 9,860 |
Boston-Downtown Crossing [Member] | | |
| Other assets | 46,080 | 46,111 |
| Total assets | 46,080 | 46,111 |
| Partners'/members' capital (deficit) | 46,080 | 46,111 |
| Total liabilities and partners'/members' capital (deficit) | 46,080 | 46,111 |
| Company's investment in unconsolidated joint ventures, net | 13,015 | 13,022 |
Gale Jefferson [Member] | | |
| Other assets | 2,657 | 2,440 |
| Total assets | 2,657 | 2,440 |
| Partners'/members' capital (deficit) | 2,657 | 2,440 |
| Total liabilities and partners'/members' capital (deficit) | 2,657 | 2,440 |
| Company's investment in unconsolidated joint ventures, net | $ 1,063 | $ 995 |