| Expected Future Minimum Payment Obligations for Non-Cancelable Operating Leases Exceeding One Year (Detail) (USD $) In Millions, unless otherwise specified | Dec. 31, 2011 | 
|---|---|
| Operating Leased Assets [Line Items] | |
| 2012 | $ 18.6 | 
| 2013 | 14.6 | 
| 2014 | 10.2 | 
| 2015 | 7.9 | 
| 2016 | 6.0 | 
| Thereafter | 34.9 | 
| Operating Leases, Future Minimum Payments Due, Total | $ 92.2 | 
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- Details 
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- Definition The total of future contractually required payments on leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within one year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fifth year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fourth year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the third year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the second year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due after the fifth year from the balance sheet date on leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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