Fair Value (Carrying Amount And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Millions |
Sep. 30, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Debt Instrument [Line Items] | ||
| Current portion of long-term debt-affiliated | $ 0.0 | |
| Current Portion of Long Term Debt-affiliated, Fair Value | 0.0 | |
| Long-term debt-affiliated, Carrying Amount | 630.9 | |
| Long-term debt-affiliated, Estimated Fair Value | $ 630.9 | |
| Predecessor | ||
| Debt Instrument [Line Items] | ||
| Current portion of long-term debt-affiliated | $ 115.9 | |
| Current Portion of Long Term Debt-affiliated, Fair Value | 120.0 | |
| Long-term debt-affiliated, Carrying Amount | 1,472.8 | |
| Long-term debt-affiliated, Estimated Fair Value | $ 1,550.4 |