Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Outstanding Stock Options, Vested and Expected to Vest, Non-Vested and Stock Options Currently Exercisable (Detail)

v3.3.1.900
Stock-based Compensation - Outstanding Stock Options, Vested and Expected to Vest, Non-Vested and Stock Options Currently Exercisable (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Number of options, options fully vested and expected to vest 5,795,711.400391 5,545,427.372753
Weighted average remaining contractual life (in years), options fully vested and expected to vest 7 years 6 months 7 years 7 months 28 days
Weighted average exercise price, options fully vested and expected to vest (in dollars per share) $ 19.43 $ 18.88
Aggregate intrinsic value, options fully vested and expected to vest $ 21,080 $ 22,012
Number of shares options, options exercisable 2,843,655 2,455,134
Weighted average remaining contractual life (in years), options exercisable 6 years 4 months 24 days 6 years 6 months 26 days
Weighted average exercise price, options exercisable (in dollars per share) $ 18.67 $ 17.04
Aggregate intrinsic value, options exercisable $ 13,316 $ 14,704