XML 89 R76.htm IDEA: XBRL DOCUMENT v3.10.0.1
Share-based Compensation - Option Grant Fair Value Assumptions (Detail)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Expected volatility 41.63% 43.95% 46.04%
Expected dividends 0.00% 0.00% 0.00%
Expected term (in years) 5 years 11 months 26 days 5 years 11 months 15 days 5 years 9 months 18 days
Risk-free rate 2.66% 2.09% 1.32%