Debt - Summary of Long-term Debt (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Line of Credit Facility [Line Items]
Total debt	$ 78.7	$ 62.0	$ 72.5
Less current portion	0.8	1.2	0.4
Long-term debt	77.9	60.8	72.1
Revolving credit facility [Member]
Line of Credit Facility [Line Items]
Total debt	76.9	59.8	72.0
Other obligations [Member]
Line of Credit Facility [Line Items]
Total debt	$ 1.8	$ 2.2	$ 0.5