XML 103 R65.htm IDEA: XBRL DOCUMENT v3.10.0.1
Employee Stock-based Compensation Plans - Fair Value of Each Option Award on the Grant Date Using the Black-Scholes Option-Pricing Model (Detail)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Dividend yield 0.00% 0.00%
Risk-free interest rate 1.99% 2.08%
Expected volatility 35.00% 35.20%
Expected term (years) 6 years 3 months 18 days 6 years 3 months 18 days