XML 61 R52.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation (Stock Options) - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total pre-tax intrinsic value of options exercised $ 33  
Number of Stock options, granted 0 0
Unvested Stock Options [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Unrecognized compensation expense related to stock options $ 2,500  
Recognition period of unvested compensation expense 1 year 3 months 18 days