| 
           Fair Value Measurements - Assets or Liabilities Recorded at Fair Value (Parenthetical) (Detail) (USD $) 
        In Millions, unless otherwise specified  | 
        
           Sep. 30, 2014 
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           Dec. 31, 2013 
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|---|---|---|
| 
           Cash Flow Swaps Designated as Hedges [Member] 
         | 
        ||
| Derivatives, Fair Value [Line Items] | ||
| Amount included in other accrued liabilities | $ 8.6 | $ 10.6 | 
| Amount included in other long-term liabilities | 2.5 | 7.4 | 
| 
           Cash Flow Swaps Not Designated as Hedges [Member] 
         | 
        ||
| Derivatives, Fair Value [Line Items] | ||
| Amount included in other accrued liabilities | 0.7 | 1.0 | 
| Amount included in other long-term liabilities | $ 0.9 | $ 1.0 | 
| X | ||||||||||
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- Definition 
          Amount of derivative liability included in other accrued liabilities. No definition available. 
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| X | ||||||||||
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- Definition 
          Amount of derivative liability included in other long-term liabilities. No definition available. 
  | 
        
| X | ||||||||||
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- Details 
          
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