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Share-Based Compensation - Summary of Weighted Average Assumptions Used for Options Granted (Detail)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Dividend yield (in percentage) 0.00%    
Stock Option Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected life (in years) 6 years 6 years 6 years
Expected volatility (in percentage) 26.60% 26.70% 28.10%
Risk-free interest rate (in percentage) 1.80% 2.70% 2.00%
Expected forfeiture rate (in percentage) 0.00% 0.00% 0.00%