Annual report pursuant to Section 13 and 15(d)

Recent Transactions (Schedule Of Disposed Properties) (Details)

v3.10.0.1
Recent Transactions (Schedule Of Disposed Properties) (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
USD ($)
ft²
property
item
Dec. 31, 2017
USD ($)
ft²
item
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Mar. 31, 2018
USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
New mortgage loan/(repayments)   $ 44,695      
Carrying Amount of Mortgages $ 45,242 $ 45,734    
Impairment charge 24,566        
Valuation allowance $ 10,100        
Disposal Group, Not Discontinued Operations [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 30 60      
Rentable Square Feet, Disposed | ft² 2,405,654 4,677,058      
Net Sales Proceeds $ 324,050 $ 399,332      
Net Carrying Value 204,479 384,637      
Realized Gains (losses)/Unrealized Losses, net 119,571 14,695      
Unrealized losses on rental properties held for sale (20,135) (12,331)      
Totals $ 99,436 $ 2,364      
Disposal Group, Not Discontinued Operations [Member] | Cranford Portfolio [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   6      
Rentable Square Feet, Disposed | ft²   435,976      
Net Sales Proceeds   $ 26,598      
Net Carrying Value   22,736      
Realized Gains (losses)/Unrealized Losses, net   $ 3,862      
Disposal Group, Not Discontinued Operations [Member] | 440 Route 22 East [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   198,376      
Net Sales Proceeds   $ 10,074      
Net Carrying Value   10,069      
Realized Gains (losses)/Unrealized Losses, net   $ 5      
Impairment charge     $ 7,700    
Disposal Group, Not Discontinued Operations [Member] | 3 Independence Way [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   111,300      
Net Sales Proceeds   $ 11,549      
Net Carrying Value   9,910      
Realized Gains (losses)/Unrealized Losses, net   $ 1,639      
Disposal Group, Not Discontinued Operations [Member] | 103 Carnegie Center [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   96,000      
Net Sales Proceeds   $ 15,063      
Net Carrying Value   8,271      
Realized Gains (losses)/Unrealized Losses, net   $ 6,792      
Disposal Group, Not Discontinued Operations [Member] | 400 Chestnut Ridge Road [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   89,200      
Net Sales Proceeds   $ 6,891      
Net Carrying Value   7,498      
Realized Gains (losses)/Unrealized Losses, net   $ (607)      
Disposal Group, Not Discontinued Operations [Member] | 140 East Ridgewood Avenue [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   239,680      
Net Sales Proceeds   $ 30,201      
Net Carrying Value   30,737      
Realized Gains (losses)/Unrealized Losses, net   $ (536)      
Disposal Group, Not Discontinued Operations [Member] | Bergen Portfolio [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   5      
Rentable Square Feet, Disposed | ft²   1,061,544      
Net Sales Proceeds   $ 86,973      
Net Carrying Value   135,121      
Realized Gains (losses)/Unrealized Losses, net   (48,148)      
Disposal Group, Not Discontinued Operations [Member] | Bergen Portfolio [Member] | Buyer [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Notes receivable   $ 65,000      
Disposal Group, Not Discontinued Operations [Member] | 377 Summerhill Road [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   40,000      
Net Sales Proceeds   $ 3,221      
Net Carrying Value   2,172      
Realized Gains (losses)/Unrealized Losses, net   1,049      
Disposal Group, Not Discontinued Operations [Member] | 700 Executive Boulevard [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Net Sales Proceeds   5,717      
Net Carrying Value   970      
Realized Gains (losses)/Unrealized Losses, net   $ 4,747      
Disposal Group, Not Discontinued Operations [Member] | Totowa Portfolio [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   13      
Rentable Square Feet, Disposed | ft²   499,243      
Net Sales Proceeds   $ 63,624      
Net Carrying Value   27,630      
Realized Gains (losses)/Unrealized Losses, net   $ 35,994      
Disposal Group, Not Discontinued Operations [Member] | 890 Mountain Avenue [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   80,000      
Net Sales Proceeds   $ 4,852      
Net Carrying Value   6,139      
Realized Gains (losses)/Unrealized Losses, net   $ (1,287)      
Impairment charge       $ 7,000  
Disposal Group, Not Discontinued Operations [Member] | 135 Chestnut Ridge Road [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   66,150      
Net Sales Proceeds   $ 5,844      
Net Carrying Value   2,929      
Realized Gains (losses)/Unrealized Losses, net   2,915      
Impairment charge       $ 4,200  
Net sales proceeds held by qualified intermediary   $ 5,900      
Disposal Group, Not Discontinued Operations [Member] | Moorestown Portfolio [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   26      
Rentable Square Feet, Disposed | ft²   1,260,398      
Net Sales Proceeds   $ 73,393      
Net Carrying Value   56,186      
Realized Gains (losses)/Unrealized Losses, net   17,207      
Net sales proceeds held by qualified intermediary   15,300      
Disposal Group, Not Discontinued Operations [Member] | 1 Enterprise Boulevard [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Net Sales Proceeds   3,230      
Net Carrying Value   1,380      
Realized Gains (losses)/Unrealized Losses, net   $ 1,850      
Disposal Group, Not Discontinued Operations [Member] | 61 South Paramus Road [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   269,191      
Net Sales Proceeds   $ 23,255      
Net Carrying Value   37,184      
Realized Gains (losses)/Unrealized Losses, net   $ (13,929)      
Disposal Group, Not Discontinued Operations [Member] | 300 Tice Boulevard [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item   1      
Rentable Square Feet, Disposed | ft²   230,000      
Net Sales Proceeds   $ 28,847      
Net Carrying Value   25,705      
Realized Gains (losses)/Unrealized Losses, net   3,142      
Disposal Group, Not Discontinued Operations [Member] | 35 Waterview Boulevard [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 1        
Rentable Square Feet, Disposed | ft² 172,498        
Net Sales Proceeds $ 25,994        
Net Carrying Value 25,739        
Realized Gains (losses)/Unrealized Losses, net $ 255        
Valuation allowance   700      
Disposal Group, Not Discontinued Operations [Member] | Hamilton Portfolio [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 6        
Rentable Square Feet, Disposed | ft² 239,262        
Net Sales Proceeds $ 17,546        
Net Carrying Value 17,501        
Realized Gains (losses)/Unrealized Losses, net $ 45        
Valuation allowance   600      
Disposal Group, Not Discontinued Operations [Member] | Wall Portfolio First Closing [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 5        
Rentable Square Feet, Disposed | ft² 179,601        
Net Sales Proceeds $ 14,053        
Net Carrying Value 10,526        
Realized Gains (losses)/Unrealized Losses, net $ 3,527        
Disposal Group, Not Discontinued Operations [Member] | 700 Horizon Drive [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 1        
Rentable Square Feet, Disposed | ft² 120,000        
Net Sales Proceeds $ 33,020        
Net Carrying Value 16,053        
Realized Gains (losses)/Unrealized Losses, net $ 16,967        
Disposal Group, Not Discontinued Operations [Member] | Wall Portfolio Second Closing [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 3        
Rentable Square Feet, Disposed | ft² 217,822        
Net Sales Proceeds $ 30,209        
Net Carrying Value 12,961        
Realized Gains (losses)/Unrealized Losses, net $ 17,248        
Disposal Group, Not Discontinued Operations [Member] | 75 Livingston Avenue [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 1        
Rentable Square Feet, Disposed | ft² 94,221        
Net Sales Proceeds $ 7,983        
Net Carrying Value 5,609        
Realized Gains (losses)/Unrealized Losses, net $ 2,374        
Disposal Group, Not Discontinued Operations [Member] | 20 Waterview Boulevard [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 1        
Rentable Square Feet, Disposed | ft² 225,550        
Net Sales Proceeds $ 12,475        
Net Carrying Value 11,795        
Realized Gains (losses)/Unrealized Losses, net $ 680        
Valuation allowance   $ 11,000      
Disposal Group, Not Discontinued Operations [Member] | 20 Waterview Boulevard [Member] | Notes Receivable 6.0 Interest Rate [Member] | Buyer [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Noncash net sales proceeds         $ 2,800
Disposal Group, Not Discontinued Operations [Member] | Westchester Financial Center [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 2        
Rentable Square Feet, Disposed | ft² 489,000        
Net Sales Proceeds $ 81,769        
Net Carrying Value 64,679        
Realized Gains (losses)/Unrealized Losses, net 17,090        
Disposal Group, Not Discontinued Operations [Member] | Westchester Financial Center [Member] | Notes Receivable 3.0 Interest Rate [Member] | Buyer [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Noncash net sales proceeds $ 4,000        
Disposal Group, Not Discontinued Operations [Member] | 65 Jackson Drive [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 0        
Net Sales Proceeds $ 1,510        
Realized Gains (losses)/Unrealized Losses, net $ 1,510        
Disposal Group, Not Discontinued Operations [Member] | 600 Horizon Drive [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 1        
Rentable Square Feet, Disposed | ft² 95,000        
Net Sales Proceeds $ 15,127        
Net Carrying Value 6,191        
Realized Gains (losses)/Unrealized Losses, net $ 8,936        
Disposal Group, Not Discontinued Operations [Member] | 1 & 3 Barker Avenue [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 2        
Rentable Square Feet, Disposed | ft² 133,300        
Net Sales Proceeds $ 15,140        
Net Carrying Value 13,543        
Realized Gains (losses)/Unrealized Losses, net $ 1,597        
Disposal Group, Not Discontinued Operations [Member] | 120 West Passaic Street [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 1        
Rentable Square Feet, Disposed | ft² 52,000        
Net Sales Proceeds $ 2,667        
Net Carrying Value 2,568        
Realized Gains (losses)/Unrealized Losses, net $ 99        
Disposal Group, Not Discontinued Operations [Member] | Elmsford Distribution Center [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of Buildings, Disposed | item 6        
Rentable Square Feet, Disposed | ft² 387,400        
Net Sales Proceeds $ 66,557        
Net Carrying Value 17,314        
Realized Gains (losses)/Unrealized Losses, net $ 49,243        
Land [Member] | Disposal Group, Not Discontinued Operations [Member] | Hamilton Portfolio [Member]          
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]          
Number of properties disposed | property 2