Quarterly Results of Operations - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Effect Of Fourth Quarter Events [Line Items]                      
Pre-tax income related to insurance recoveries         $ 200 $ 100 $ 300 $ 3,100 $ 443 $ 3,657 $ 10,368
Adjustment to the reserve for uncertain tax positions, net               $ 3,000      
Basic and diluted net income (loss) per share $ 0.20 $ 0.15 $ 0.02 $ (0.05) $ (0.11) $ 0.02 $ (0.60) $ 0.21 $ 0.31 $ (0.49) $ 0.59
Workforce Reduction Charges                      
Effect Of Fourth Quarter Events [Line Items]                      
Basic and diluted net income (loss) per share             (0.07)        
Other-Than-Temporary Impairment Charge in Marketable Equity Security                      
Effect Of Fourth Quarter Events [Line Items]                      
Basic and diluted net income (loss) per share           $ (0.03)          
Insurance Settlement Gains                      
Effect Of Fourth Quarter Events [Line Items]                      
Basic and diluted net income (loss) per share       $ 0.01              
Execution and Finalization of Agreement | US-Canada APA                      
Effect Of Fourth Quarter Events [Line Items]                      
Basic and diluted net income (loss) per share (0.01) $ 0.02                  
Increase (Decrease) in Uncertain Tax Positions                      
Effect Of Fourth Quarter Events [Line Items]                      
Basic and diluted net income (loss) per share (0.01)                    
Deferred Income Tax Asset Valuation Allowance                      
Effect Of Fourth Quarter Events [Line Items]                      
Basic and diluted net income (loss) per share $ 0.02   $ (0.01)       $ (0.65)