Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Additional Information (Detail)

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Commitments and Contingencies - Additional Information (Detail) (USD $)
 12 Months Ended
Dec. 31, 2012
LegalMatter
Dec. 31, 2011
Dec. 31, 2010
Commitment And Contingencies [Line Items]      
Rent expense for operating leases $ 11,800,000 $ 12,100,000 $ 12,000,000
Exposure per occurrence 250,000    
Aggregate deductible for protection and indemnity and maritime employers' liability claims 500,000    
Auto liability claims 100,000    
Gross self insurance accruals 4,700,000 6,600,000  
Related insurance recoveries 1,200,000 1,900,000  
Number of Lawsuits 15    
Percent of costs to study and remediate site 20.00%    
Amount accrued 0    
Deferred term for criminal violations of anti-bribery provisions of FCPA 3 years    
Fine paid by for retention and use of individual agent in Nigeria with respect to customs-related issues 11,760,000    
Payment of disgorgement 3,050,000    
Prejudgment interest 1,040,000    
Prejudgment interest and disgorgement amount paid 4,090,000    
Proposed settlement 15,850,000    
Gulfco Site [Member]
      
Commitment And Contingencies [Line Items]      
Amount accrued   $ 700,000  
Minimum [Member]
      
Commitment And Contingencies [Line Items]      
Employment agreements terms 1 year    
Maximum [Member]
      
Commitment And Contingencies [Line Items]      
Employment agreements terms 2 years