Quarterly report pursuant to Section 13 or 15(d)

Discontinued Operations (Narrative) (Details)

v3.20.2
Discontinued Operations (Narrative) (Details)
$ in Thousands
3 Months Ended 6 Months Ended 18 Months Ended
Jul. 22, 2020
USD ($)
ft²
property
Jun. 30, 2020
USD ($)
ft²
property
Jun. 30, 2019
USD ($)
Jun. 30, 2020
USD ($)
ft²
property
item
Jun. 30, 2019
USD ($)
Jun. 30, 2020
USD ($)
ft²
property
Dec. 19, 2019
ft²
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Unrealized losses on disposition of rental property   $ (11,929) $ (5,802) $ (56,997) $ (5,802)    
Suburban Office Portfolio [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Area of property (in square feet) | ft²             6,600,000
Four Disposal Group [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Number of disposal groups | item       7      
Properties | property       21      
Unrealized losses on disposition of rental property   $ 11,900   $ 57,000      
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Suburban Office Portfolio [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Number of disposal groups | item       13      
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Properties Disposed One [Member] | Suburban Office Portfolio [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Number of real estate properties | property   34   34   34  
Area of property (in square feet) | ft²   5,900,000   5,900,000   5,900,000  
Disposal Group, Not Discontinued Operations [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Number of properties sold | item       1      
Sales proceeds       $ 35,065      
Gain (loss) on sale of property       $ 17,322      
Disposal Group, Not Discontinued Operations [Member] | Suburban Office Properties [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Sales proceeds           $ 87,200  
Number of properties sold | property           3  
Area of property (in square feet) | ft²   697,000   697,000   697,000  
Disposal Group, Not Discontinued Operations [Member] | Properties Disposed Two [Member] | Suburban Office Portfolio [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Number of real estate properties | property   17   17   17  
Area of property (in square feet) | ft²   2,700,000   2,700,000   2,700,000  
Gain (loss) on sale of property       $ 305,400      
Subsequent Event [Member] | Disposal Group, Not Discontinued Operations [Member] | Suburban Office Properties [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Number of properties sold | property 1            
Subsequent Event [Member] | Disposal Group, Not Discontinued Operations [Member] | Properties Disposed Three [Member] | Suburban Office Portfolio [Member]              
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]              
Area of property (in square feet) | ft² 141,000            
Gain (loss) on sale of property $ 7,900