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Income Taxes - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Income Tax Disclosure [Abstract]          
Effective income tax rate 22.00% 26.00% 28.00% 26.00%  
Decrease in effective tax rate 3.00%        
Changes in the valuation allowances $ 0   $ 0    
Changes in balances of unrecognized tax benefits     $ 0   $ 0