v2.4.0.8
Employee Retirement and Postretirement Benefits - Additional Information (Detail) (USD $)
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Employee Benefit Plans [Line Items]      
Maximum percentage of annual gross salary allowable 15.00%    
Employee Contribution 100.00%    
Percentage of employees contribution matched by the company 4.00%    
Employer Contribution $ 2,200,000 $ 1,600,000 $ 900,000
Contingent bonus payout not yet accrued 600,000    
Description of Board of Directors compensation payment method Compensation is to be paid 1/3 in cash, 1/3 in stock options and 1/3 in DSUs.    
Board of Directors Chairman [Member]
      
Employee Benefit Plans [Line Items]      
Compensation to non employee directors 225,000    
Director [Member]
      
Employee Benefit Plans [Line Items]      
Compensation to non employee directors 150,000    
Chairman Of Audit Committee [Member]
      
Employee Benefit Plans [Line Items]      
Additional compensation to non employee directors 20,000    
Chairman Of Compensation Committee [Member]
      
Employee Benefit Plans [Line Items]      
Additional compensation to non employee directors 10,000    
Chairman Of Nominating And Governance Committee [Member]
      
Employee Benefit Plans [Line Items]      
Additional compensation to non employee directors $ 5,000