Quarterly report pursuant to Section 13 or 15(d)

Summary of Restricted Share Units Activity (Detail)

v3.7.0.1
Summary of Restricted Share Units Activity (Detail) - Restricted Share Units
6 Months Ended
Jun. 30, 2017
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares  
Number of Restricted Shares, Beginning Balance | shares 132,517
Number of Restricted Shares, Shares Granted | shares 79,223
Number of Restricted Shares, Shares Vested | shares (53,806)
Number of Restricted Shares, Ending Balance | shares 157,934
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value  
Weighted Average Grant Date Fair Value Per Share, Beginning Balance | $ / shares $ 6.84
Weighted Average Grant Date Fair Value Per Share, Shares Granted | $ / shares 7.47
Weighted Average Grant Date Fair Value Per Share, Shares Vested | $ / shares 7.83
Weighted Average Grant Date Fair Value Per Share, Ending Balance | $ / shares $ 6.82