XML 59 R49.htm IDEA: XBRL DOCUMENT v3.19.2
Share-based Compensation - Option Grant Fair Value Assumptions (Detail)
6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Expected volatility 41.14% 41.63%
Expected dividends 0.00% 0.00%
Expected term (in years) 6 years 6 years
Risk-free rate 2.55% 2.66%