Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Detail)

v3.2.0.727
Share-Based Compensation - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]        
Share-based compensation expense $ 494 $ 447 $ 1,022 $ 1,051
Related tax benefits on non-qualified stock options $ 161 $ 149 $ 337 $ 368
Number of shares, stock options exercised 6,874 18,500 26,455 33,695