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Retirement Plans - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Employer contribution 6.00%    
Employee contribution 80.00%    
Plan expense $ 3,600 $ 3,200 $ 2,800
Retirement Plan expense $ 0 $ 0 $ 0
Minimum [Member]      
Eligibility of participants 1.00%    
Maximum [Member]      
Eligibility of participants 25.00%