XML 70 R56.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock Incentive Plans - Summary of Stock Options Activity (Detail) - Stock Options [Member]
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
USD ($)
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Outstanding beginning balance, Number of Options | shares 292,400
Options granted at market price, Number of Options | shares 120,000
Options exercised, Number of Options | shares (40,140)
Outstanding ending balance, Number of Options | shares 372,260
Number of Options, exercisable stock options | shares 219,135
Outstanding beginning balance, Weighted Average Exercise Price | $ / shares $ 17.99
Options granted at market price, Weighted Average Exercise Price | $ / shares 82.21
Options exercised, Weighted Average Exercise Price | $ / shares 14.39
Outstanding ending balance, Weighted Average Exercise Price | $ / shares 39.08
Weighted Average Exercise Price, exercisable stock options | $ / shares $ 17.73
Weighted Average Remaining Contractual Term of outstanding stock options 4 years 10 months 9 days
Weighted Average Remaining Contractual Term of exercisable stock options 2 years 6 months 21 days
Aggregate Intrinsic Value, outstanding stock option | $ $ 9,759
Aggregate Intrinsic Value, exercisable stock option | $ $ 8,661