Quarterly report pursuant to Section 13 or 15(d)

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

v3.8.0.1
Recent Transactions (Rockpoint Transaction) (Narrative) (Details) - USD ($)
$ in Millions
 9 Months Ended
Mar. 10, 2017
Feb. 27, 2017
Sep. 30, 2017
Dec. 31, 2016
RRLP [Member]        
Preferred Units [Line Items]        
Assets     $ 1.8 $ 1.3
Mortgages and loans payable     698.8 480.7
Other liabilities     87.3 $ 40.1
Investment Agreement [Member] | Rockpoint [Member]        
Preferred Units [Line Items]        
Incremental closing payments, Limited Partnership interest $ 150.0      
Investment Agreement [Member] | Rockpoint [Member] | Minimum [Member]        
Preferred Units [Line Items]        
Incremental closing payments, Limited Partnership interest     $ 10.0  
Investment Agreement [Member] | Rockpoint [Member] | Maximum [Member]        
Preferred Units [Line Items]        
Contributed amount to obtain equity units   $ 300.0