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Income Taxes - Additional Information (Detail) (USD $)
 12 Months Ended 12 Months Ended
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2011
Dec. 31, 2011
Prior fiscal year
Dec. 31, 2011
Expiring in 2014
Dec. 31, 2011
Expiring in 2015
Dec. 31, 2011
Expire in 2016
Dec. 31, 2011
Expire in 2018
Dec. 31, 2011
Expire in 2028
Dec. 31, 2011
Expiring in 2029
Dec. 31, 2011
Expiring in 2030
Dec. 31, 2011
Expire in 2031
Dec. 31, 2011
U.S.
Dec. 31, 2011
U.S.
Minimum
Dec. 31, 2011
U.S.
Maximum
Dec. 31, 2011
Canada
Dec. 31, 2011
Canada
Minimum
Dec. 31, 2011
Canada
Maximum
Income Taxes [Line Items]                                    
Domestic Production Activities Deduction 9.00% 6.00%                                
Other deferred tax assets     $ 29,500,000                              
Operating losses carried forward     118,000,000                              
Deferred tax liabilities that have not been provided on such unremitted foreign earnings for United States Federal or state income taxes     25,200,000                              
Federal net operating losses     327,000,000                              
Operating losses carried back to prior years     136,000,000 11,100,000                            
Net operating losses carried forward         9,600,000 12,900,000 8,200,000 2,400,000 15,300,000 59,800,000 35,700,000 426,000,000            
Unrecognized tax benefits     0                              
Tax periods open for examination                         Tax years ended December 31, 2008 through December 31, 2010     Tax years ended December 31, 2007 through December 31, 2010    
Tax period open for examination                           2008 2010   2007 2010
Reduction in deferred tax liabilities due to statutory tax rates in Canada being lower than those in the United States $ (5,100,000)