Fair Value (Carrying Amount And Estimated Fair Values Of Financial Instruments) (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Current portion of long-term debt $ 0  
Current Portion of Long Term Debt, Fair Value 0  
Long-term debt, Carrying Amount 630.9  
Long-term debt, Estimated Fair Value 630.9  
Predecessor [Member]    
Debt Instrument [Line Items]    
Current portion of long-term debt   115.9
Current Portion of Long Term Debt, Fair Value   120.0
Long-term debt, Carrying Amount   1,472.8
Long-term debt, Estimated Fair Value   $ 1,550.4