Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.1
Recent Transactions (Rockpoint Transaction) (Narrative) (Details)
$ in Thousands
 3 Months Ended 12 Months Ended
Jun. 30, 2019
USD ($)
Jun. 26, 2019
USD ($)
property
Mar. 10, 2017
USD ($)
Feb. 27, 2017
USD ($)
Mar. 31, 2020
USD ($)
Mar. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Preferred Units [Line Items]              
Payment for borrowings         $ 121,000 $ 204,000  
Investment Agreement [Member] | Minimum [Member]              
Preferred Units [Line Items]              
Incremental closing payments, Limited Partnership interest             $ 105,000
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] | Maximum [Member]              
Preferred Units [Line Items]              
Contributed amount to obtain equity units       $ 300,000   $ 300,000  
Preferred Units, Contribution To Obtain Equity Units       $ 300,000      
Add On Investment Agreement [Member] | Maximum [Member]              
Preferred Units [Line Items]              
Preferred Units, Contribution To Obtain Equity Units $ 154,000            
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       100,000    
Add On Investment Agreement [Member] | Rockpoint [Member] | Maximum [Member]              
Preferred Units [Line Items]              
Preferred Units, Contribution To Obtain Equity Units         $ 154,000