XML 99 R86.htm IDEA: XBRL DOCUMENT v3.20.4
Share-based Compensation - Option Grant Fair Value Assumptions (Detail)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Expected volatility 45.36% 41.06% 41.63%
Expected dividends 0.34% 0.00% 0.00%
Expected term (in years) 6 years 6 years 6 years
Risk-free rate 0.68% 2.41% 2.66%