Quarterly report pursuant to Section 13 or 15(d)

Summary of Stock Option Activity (Detail)

v3.7.0.1
Summary of Stock Option Activity (Detail) - 2003 Plan - $ / shares
6 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of Option, Beginning Balance 27,828  
Number of Option, Expired (2,900)  
Number of Option, Ending Balance 24,928 27,828
Number of Option, Exercisable, June 30, 2017 24,928  
Weighted Average Exercise Price, Beginning Balance $ 44.76  
Weighted Average Exercise Price, Expired 47.40  
Weighted Average Exercise Price, Ending Balance 44.45 $ 44.76
Weighted Average Exercise Price, Exercisable, June 30, 2017 $ 44.45  
Weighted Average Contractual Life 2 years 9 months 25 days 3 years 4 days
Weighted Average Contractual Life, Exercisable, June 30, 2017 2 years 9 months 25 days