Quarterly report pursuant to Section 13 or 15(d)

Recent Transactions (Rockpoint Transaction) (Narrative) (Details)

v3.19.3
Recent Transactions (Rockpoint Transaction) (Narrative) (Details)
$ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Jun. 30, 2019
USD ($)
Jun. 26, 2019
USD ($)
property
Mar. 10, 2017
USD ($)
Feb. 27, 2017
USD ($)
Mar. 31, 2019
USD ($)
Sep. 30, 2019
USD ($)
Sep. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
Preferred Units [Line Items]                
Payment for borrowings           $ 398,000 $ 381,000  
Investment Agreement [Member] | Rockpoint [Member]                
Preferred Units [Line Items]                
Incremental closing payments, Limited Partnership interest   $ 46,000 $ 150,000   $ 45,000     $ 105,000
Contributed equity value     $ 1,230,000          
Investment Agreement [Member] | Rockpoint [Member] | Minimum [Member]                
Preferred Units [Line Items]                
Incremental closing payments, Limited Partnership interest               $ 105,000
Investment Agreement [Member] | Rockpoint [Member] | Maximum [Member]                
Preferred Units [Line Items]                
Contributed amount to obtain equity units       $ 300,000 $ 300,000      
Add On Investment Agreement [Member] | Rockpoint [Member]                
Preferred Units [Line Items]                
Contributed amount to obtain equity units   $ 100,000            
Number of properties in which additional interest was acquired during period | property   2            
Payment for borrowings $ 100,000              
Right of first refusal to invest $ 100,000