XML 58 R47.htm IDEA: XBRL DOCUMENT v3.8.0.1
Share-Based Compensation - Stock Option Activity under Company's Plan - Long Term Incentive Plan (Detail) - Long Term Incentive Plan Stock Option [Member] - USD ($)
$ / shares in Units, $ in Thousands
9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Outstanding at January 1, 2017, Number of Shares 52,750  
Granted, Number of Shares 5,000 1,000
Exercised, Number of Shares 0 (1,000)
Forfeited, Number of Shares 0  
Outstanding (vested and expected to vest) at September 30, 2017, Number of Shares 57,750  
Exercisable at September 30, 2017, Number of Shares 44,625  
Outstanding at January 1, 2017, Weighted Average Exercise Price per Share $ 54.54  
Granted, Weighted Average Exercise Price per Share 48.00  
Exercised, Weighted Average Exercise Price per Share 0.00  
Forfeited, Weighted Average Exercise Price per Share 0.00  
Outstanding (vested and expected to vest) at September 30, 2017, Weighted Average Exercise Price per Share 53.98  
Exercisable at September 30, 2017, Weighted Average Exercise Price per Share $ 56.34  
Outstanding (vested and expected to vest) at September 30, 2017, Weighted Average Remaining Contractual Term (Years) 6 years 9 months 18 days  
Exercisable at September 30, 2017, Weighted Average Remaining Contractual Term (Years) 6 years 2 months 12 days  
Outstanding (vested and expected to vest) at September 30, 2017, Aggregate Intrinsic Value $ 821  
Exercisable at September 30, 2017, Aggregate Intrinsic Value $ 541