Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Derivative Instruments and Hedging Activities (Details)

v3.8.0.1
Long-Term Debt - Derivative Instruments and Hedging Activities (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Derivatives, Fair Value [Line Items]      
Incremental interest expense $ 0.1 $ 1.2  
Net benefit expected to be reclassified 1.0    
Interest rate swap and interest rate cap | Derivative instruments and hedging activities      
Derivatives, Fair Value [Line Items]      
Derivative asset, fair value of interest rate swap and cap positions 6.7    
Net cash proceeds 4.8    
Interest rate swap | Derivative instruments and hedging activities      
Derivatives, Fair Value [Line Items]      
Fair value of outstanding interest rate swap and interest rate cap     $ 4.7
Other assets | Interest rate swap and interest rate cap | Derivative instruments and hedging activities      
Derivatives, Fair Value [Line Items]      
Derivative asset, fair value of interest rate swap and cap positions 6.1   5.1
Other current assets | Interest rate swap and interest rate cap | Derivative instruments and hedging activities      
Derivatives, Fair Value [Line Items]      
Derivative asset, fair value of interest rate swap and cap positions $ 0.6    
Other current assets | Interest rate swap | Derivative instruments and hedging activities      
Derivatives, Fair Value [Line Items]      
Derivative liability, fair value of interest rate swap and cap positions     0.9
Other long-term liabilities | Interest rate swap | Derivative instruments and hedging activities      
Derivatives, Fair Value [Line Items]      
Derivative liability, fair value of interest rate swap and cap positions     0.3
Other accrued liabilities | Interest rate swap | Derivative instruments and hedging activities      
Derivatives, Fair Value [Line Items]      
Derivative liability, fair value of interest rate swap and cap positions     $ 1.0