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401 (k) Plan - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]      
Maximum contribution by employee, percentage of pretax earnings 60.00%    
Percentage of company's matching contribution with respect to each participant's contribution 100.00%    
Company matching contributions to maximum employees eligible compensation 5.00%    
Company contributions to 401 (k) plan $ 4.3 $ 3.6 $ 3.3