Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Detail)

v3.7.0.1
Share-Based Compensation - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]        
Share-based compensation expense $ 670 $ 923 $ 1,363 $ 1,542
Related tax benefits on non-qualified stock options $ 274 $ 366 $ 550 $ 604
Number of shares, stock options exercised 10,500 18,000 11,500 40,209