Carrying and Estimated Fair Values of Financial Instruments (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Fair Value Assets Liabilities Quantitative Information [Line Items]
Cash and cash equivalents, Carrying Amount	$ 75.7	$ 70.8	$ 33.5	$ 61.3
Restricted Cash, Carrying Amount	3.8	3.9
Receivables less provision for allowances, claims and doubtful accounts, Carrying Amount	436.0	396.7
Accounts payable, Carrying Amount	235.5	196.2
Long-term debt, including current portion, Carrying Amount	1,268.6	1,305.4
Fair Value
Fair Value Assets Liabilities Quantitative Information [Line Items]
Cash and cash equivalents, Fair Value	75.7	70.8
Restricted Cash, Fair Value	3.8	3.9
Receivables less provision for allowances, claims and doubtful accounts, Fair Value	436.0	396.7
Accounts payable, Fair Value	235.5	196.2
Long-term debt, including current portion, Fair Value	1,276.1	1,296.4
Carrying Amount
Fair Value Assets Liabilities Quantitative Information [Line Items]
Cash and cash equivalents, Carrying Amount	75.7	70.8
Restricted Cash, Carrying Amount	3.8	3.9
Receivables less provision for allowances, claims and doubtful accounts, Carrying Amount	436.0	396.7
Accounts payable, Carrying Amount	235.5	196.2
Long-term debt, including current portion, Carrying Amount	$ 1,268.6	$ 1,305.4