Initial Public Offering (Schedule fo Change From Net Income Attributable to the Partnership and Transfers to Noncontrolling Interest) (Details) - USD ($)
$ in Millions
2 Months Ended 3 Months Ended 11 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Dec. 31, 2015
Dec. 31, 2015
Initial Public Offering [Line Items]            
Net Income (Loss) Allocated to Limited Partners $ 13.3 $ 22.4 $ 22.0 $ 16.3 $ 74.0 $ 74.0
Noncontrolling Interest, Increase from Subsidiary Equity Issuance         0.0  
Change from net income attributable to the Partnership and transfers to noncontrolling interest         (350.4)  
Noncontrolling Interest            
Initial Public Offering [Line Items]            
Noncontrolling Interest, Increase from Subsidiary Equity Issuance         $ (424.4)