Share-based Compensation - Schedule of Assumptions Used in Determining Fair Value of Stock Options Granted (Detail) - $ / shares |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
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Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract] | |||
Expected term (in years) | 5 years 6 months | 5 years | 4 years 6 months |
Expected volatility, minimum | 30.20% | 29.70% | 28.70% |
Expected volatility, maximum | 35.10% | 31.00% | 30.10% |
Risk free interest rate, minimum | 0.28% | 1.38% | 2.55% |
Risk free interest rate, maximum | 1.65% | 2.31% | 2.79% |
Weighted average grant date fair value | $ 8.74 | $ 14.64 | $ 16.28 |