XML 75 R58.htm IDEA: XBRL DOCUMENT v3.10.0.1
Employee Benefit Plans and Stockholders' Equity - Schedule of Intrinsic Value of Options Exercised and Fair Value of Options Vested (Detail) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2017
Dec. 31, 2018
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Intrinsic value of options exercised $ 21.6 $ 30.0 $ 39.9