| Investments In Unconsolidated Joint Ventures (Roseland/Port Imperial Partners, L.P.) (Narrative) (Details) (Roseland/Port Imperial Partners, L.P. [Member], USD $) | 9 Months Ended | |
|---|---|---|
| Sep. 30, 2013 | Oct. 23, 2012
 item | |
| Schedule of Equity Method Investments [Line Items] | ||
| Residual ownership interest | 20.00% | |
| Number of units | 363 | |
| Percentage of operating return on capital | 10.00% | |
| Percentage of return on additional capital contribution | 10.00% | |
| Holding and distribution pattern under operating agreement | The operating agreement of Roseland/PI provides, among other things, for the distribution of net cash flow to the members, as follows:to Prudential and Prudential LLC, in proportion to the excess of their operating return of ten percent on Prudential's Parcel C contribution, as defined, accrued to the date of such distribution over the aggregate amounts previously distributed to such partner for such return; to the partners, to the extent of any excess of such partner's operating return of ten percent on its additional capital contributions over the aggregate amounts previously distributed for such return; andto the partners in accordance with their percentage interests. | |
| Prudential [Member] | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Third party ownership percentage | 79.00% | |
| Prudential-Port Imperial, L.L.C. [Member] | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Third party ownership percentage | 1.00% | |
| Prudential And Prudential-Port Imperial, L.L.C. [Member] | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Accumulated unpaid operating return | $ 23,000 | |
| Capital balance | 584,000 | |
| Parent Company [Member] | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Accumulated unpaid operating return | 6,000 | |
| Capital balance | 146,000 | |
| Land [Member] | Prudential And Prudential-Port Imperial, L.L.C. [Member] | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Capital balance | 57,700,000 | |
| Land [Member] | Parent Company [Member] | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Capital balance | 5,000,000 | |
| Parcel C [Member] | Prudential And Prudential-Port Imperial, L.L.C. [Member] | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Accumulated unpaid operating return | 3,800,000 | |
| Capital balance | 18,200,000 | |
| Parcel C [Member] | Parent Company [Member] | ||
| Schedule of Equity Method Investments [Line Items] | ||
| Capital balance | $ 26,000 | 
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- Definition Accumulated Unpaid Operating Return No definition available. 
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- Definition Holding And Distribution Pattern Under Operating Agreement No definition available. 
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- Definition Percentage Of Operating Return On Capital No definition available. 
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- Definition Percentage Of Return On Additional Capital Contributions No definition available. 
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- Definition Residual Ownership Interest No definition available. 
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- Definition Third Party Ownership Percent No definition available. 
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- Definition The number of units in a real estate property owned as of the balance sheet date. No definition available. 
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- Definition The amount of ownership interest of different classes of partners in limited partnership. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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