Disclosure Of Fair Value Of Assets And Liabilities (Narrative) (Details)
|
12 Months Ended |
|
Dec. 31, 2018
USD ($)
property
item
|
Dec. 31, 2017
USD ($)
property
|
| Fair Value Measurement Inputs and Valuation Techniques [Line Items] |
|
|
| Fair value of Company's long-term debt |
$ 2,711,712,000
|
$ 2,764,033,000
|
| Principal balance outstanding |
2,792,651,000
|
2,809,568,000
|
| Aggregate carrying value |
108,848,000
|
171,578,000
|
| Land impairments |
24,566,000
|
|
| Office [Member] | Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member] |
|
|
| Fair Value Measurement Inputs and Valuation Techniques [Line Items] |
|
|
| Unrealized losses on rental properties held for sale |
20,100,000
|
|
| Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Parsippany, Paramus, Rochelle Park, Hamilton And Wall, New Jersey And White Plains, New York [Member] |
|
|
| Fair Value Measurement Inputs and Valuation Techniques [Line Items] |
|
|
| Aggregate carrying value |
|
$ 171,578,000
|
| Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member] |
|
|
| Fair Value Measurement Inputs and Valuation Techniques [Line Items] |
|
|
| Aggregate carrying value |
$ 108,848,000
|
|
| Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member] | Parsippany, Paramus, Rochelle Park, Hamilton And Wall, New Jersey And White Plains, New York [Member] |
|
|
| Fair Value Measurement Inputs and Valuation Techniques [Line Items] |
|
|
| Number of properties held for sale | property |
|
21
|
| Aggregate carrying value |
|
$ 171,600,000
|
| Estimated expected sales proceeds |
|
$ 223,000,000
|
| Number of properties not expected to recover from estimated net sales proceeds | property |
|
7
|
| Unrealized losses on rental properties held for sale |
|
$ 12,300,000
|
| Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Office [Member] | Fort Lee, Newark, Paramus, Bridgewater, Morris Plains And Rahway, New Jersey [Member] |
|
|
| Fair Value Measurement Inputs and Valuation Techniques [Line Items] |
|
|
| Number of properties held for sale | property |
6
|
|
| Aggregate carrying value |
$ 108,800,000
|
|
| Estimated expected sales proceeds |
$ 124,000,000
|
|
| Number of properties not expected to recover from estimated net sales proceeds | property |
4
|
|
| Unrealized losses on rental properties held for sale |
$ 20,100,000
|
|
| Number of real estate properties | item |
159
|
|
| Disposal Group, Not Discontinued Operations [Member] |
|
|
| Fair Value Measurement Inputs and Valuation Techniques [Line Items] |
|
|
| Unrealized losses on rental properties held for sale |
$ (20,135,000)
|
$ (12,331,000)
|