XML 63 R52.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation - Summary of Activity Under Stock Option Plan (Detail)
$ / shares in Units, $ in Thousands
 9 Months Ended
Sep. 30, 2017
USD ($)
$ / shares
shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Outstanding at beginning period - Options | shares 1,414,900
Options granted | shares 80,000
Options exercised | shares (231,275)
Outstanding at ending period - Options | shares 1,263,625
Exercisable at ending period - Options | shares 523,625
Outstanding at beginning period - Wgtd. Avg. Exercise Price | $ / shares $ 22.46
Options granted - Wgtd. Avg. Exercise Price | $ / shares 46.63
Options exercised - Wgtd. Avg. Exercise Price | $ / shares 17.78
Outstanding at ending period - Wgtd. Avg. Exercise Price | $ / shares 24.84
Exercisable at ending period - Wgtd. Avg. Exercise Price | $ / shares $ 19.44
Outstanding at ending period - Wgtd. Avg. Remaining Contractual Term, years 9 years 8 months 19 days
Exercisable at ending period - Wgtd. Avg. Remaining Contractual Term, years 6 years 8 months 2 days
Outstanding at ending period - Aggregate Intrinsic Value | $ $ 40,317
Exercisable at ending period - Aggregate Intrinsic Value | $ $ 19,539