Fair Value (Tables)
12 Months Ended
Dec. 31, 2015
Fair Value Disclosures [Abstract]  
Carrying Amount And Estimated Fair Values Of Financial Instruments
At December 31, (in millions)
Carrying
Amount
2015
 
Estimated
Fair Value
2015
 
Carrying
Amount
2014
 
Estimated
Fair Value
2014
 
 
 
 
 
Predecessor
Current portion of long-term debt-affiliated
$

 
$

 
$
115.9

 
$
120.0

Long-term debt-affiliated
630.9

 
630.9

 
1,472.8

 
1,550.4