Debt - Summary of Components of Long-Term Borrowings and Capital Lease Obligations (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Borrowings [Line Items]
Total long-term borrowings and capital lease obligations, including current portion	$ 68.6	$ 92.1
Less: Current maturities	7.5	7.0
Less: Current capital lease obligations	0.4	0.4
Total long-term borrowings and capital lease obligations, net	60.7	84.7
Capital Lease Obligations
Borrowings [Line Items]
Total long-term borrowings and capital lease obligations, including current portion	1.1	1.3
Senior Secured Credit Facility | Revolving Credit Facility
Borrowings [Line Items]
Total long-term borrowings and capital lease obligations, including current portion	0	20.0
Senior Secured Credit Facility | Term Loan
Borrowings [Line Items]
Total long-term borrowings and capital lease obligations, including current portion	$ 67.5	$ 70.8