Derivatives and Fair Value Measurements - Carrying and Estimated Fair Values of Financial Instruments (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Fair Value Assets Liabilities Quantitative Information [Line Items]
Cash and cash equivalents, Carrying Amount	$ 80.7	$ 70.8	$ 54.0	$ 61.3
Restricted Cash, Carrying Amount	4.6	3.9
Receivables less provision for allowances, claims and doubtful accounts, Carrying Amount	423.5	396.7
Accounts payable, Carrying Amount	239.9	196.2
Long-term debt, including current portion, Carrying Amount	1,240.1	1,305.4
Fair Value [Member]
Fair Value Assets Liabilities Quantitative Information [Line Items]
Cash and cash equivalents, Fair Value	80.7	70.8
Restricted Cash, Fair Value	4.6	3.9
Receivables less provision for allowances, claims and doubtful accounts, Fair Value	423.5	396.7
Accounts payable, Fair Value	239.9	196.2
Long-term debt, including current portion, Fair Value	1,275.3	1,296.4
Carrying Amount [Member]
Fair Value Assets Liabilities Quantitative Information [Line Items]
Cash and cash equivalents, Carrying Amount	80.7	70.8
Restricted Cash, Carrying Amount	4.6	3.9
Receivables less provision for allowances, claims and doubtful accounts, Carrying Amount	423.5	396.7
Accounts payable, Carrying Amount	239.9	196.2
Long-term debt, including current portion, Carrying Amount	$ 1,240.1	$ 1,305.4