v3.3.0.814
Fair Value Measurements Fair Value Measurements - Fair Values - Reported (Details) - USD ($)
$ in Millions
Sep. 30, 2015
Dec. 31, 2014
Fair Value [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt $ 711.1 $ 635.6
Carrying Value [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt $ 748.3 $ 635.0