Quarterly report pursuant to Section 13 or 15(d)

Share-based Compensation - Summary of Input Variables (Detail)

v3.21.2
Share-based Compensation - Summary of Input Variables (Detail) - Performance Shares [Member]
9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 0.56% 0.18%
Expected life in years 3 years 5 months 19 days 3 years
Expected volatility 64.30% 65.90%
Expected dividend yield [1] 0.00% 0.00%
[1] The Monte Carlo method assumes a reinvestment of dividends.