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Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2016
Operating Loss Carryforwards [Line Items]        
Valuation allowance $ 82,938 $ 85,743    
Increase (decrease) in valuation allowance (2,800) 7,100    
Undistributed earnings of foreign subsidiaries 16,000 13,600    
Unrecognized tax benefits 4,585 4,441 $ 4,191 $ 3,782
Unrecognized tax benefits that would affect the effective tax rate 800      
U.S. Federal        
Operating Loss Carryforwards [Line Items]        
Operating loss carryforwards 177,000 193,800    
State        
Operating Loss Carryforwards [Line Items]        
Operating loss carryforwards 78,000 84,600    
Research and Development Credit Carryforward | U.S. Federal        
Operating Loss Carryforwards [Line Items]        
Tax credit carryforward 16,400 15,300    
Research and Development Credit Carryforward | State        
Operating Loss Carryforwards [Line Items]        
Tax credit carryforward $ 18,200 $ 16,400