Debt - Summary of Components of Long-Term Borrowings and Capital Lease Obligations (Detail) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Borrowings [Line Items]    
Total long-term borrowings and capital lease obligations, including current portion $ 50.1 $ 50.2
Less: Current maturities 5.8 5.8
Less: Current capital lease obligations 0.4 0.4
Total long-term borrowings and capital lease obligations, net 43.9 44.0
Capital Lease Obligations    
Borrowings [Line Items]    
Total long-term borrowings and capital lease obligations, including current portion 0.9 1.0
Senior Secured Credit Facility | Revolving Credit Facility    
Borrowings [Line Items]    
Total long-term borrowings and capital lease obligations, including current portion 0 0
Senior Secured Credit Facility | Term Loan    
Borrowings [Line Items]    
Total long-term borrowings and capital lease obligations, including current portion $ 49.2 $ 49.2