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Share-Based Compensation - Schedule of Grant Date Fair Values of Awards Using Monte Carlo Simulation Valuation Model (Detail)
9 Months Ended
Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Expected volatility, minimum 22.00% [1]
Expected volatility, maximum 23.00% [1]
Risk-free rate, minimum 1.20%
Risk-free rate, maximum 1.50%
Minimum [Member]  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Expected term 1 year
Maximum [Member]  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Expected term 3 years
[1] The weighted average expected volatility was 22.5%.