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Commitments and Contingencies - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Commitments and Contingencies Disclosure [Line Items]    
Profit-sharing match percentage 4.00%  
Investments to fund a future liability, market value $ 1.0 $ 1.0
Nonqualified Deferred Compensation Plan
   
Commitments and Contingencies Disclosure [Line Items]    
Maximum participant percentage election to defer cash compensation 100.00%  
Accumulated benefit obligation $ 1.0 $ 1.0