Annual report pursuant to Section 13 and 15(d)

Retirement Plans - Additional Information (Detail)

v3.20.4
Retirement Plans - Additional Information (Detail) - Contribution Plan [Member] - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan minimum eligible period have completed one month of service.    
Defined contribution plan, maximum percentage of employee contribution 100.00%    
Defined contribution plan, maximum annual employer contribution per employee $ 4,000    
Defined contribution plan, matching employer contributions $ 1,000,000.0 $ 1,100,000 $ 920,000
Matching contribution suspension, Effective date May 15, 2020    
One Year of Service [Member]      
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan, vesting percentage per year 33.00%    
Two Year of Service [Member]      
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan, vesting percentage per year 66.00%    
Three Year of Service [Member]      
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan, vesting percentage per year 100.00%