Quarterly report pursuant to Section 13 or 15(d)

Summary of Restricted Shares Activity (Detail)

v3.10.0.1
Summary of Restricted Shares Activity (Detail) - Restricted Stock
6 Months Ended
Jun. 30, 2018
$ / 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 223,499
Number of Restricted Shares, Shares Vested | shares (122,663)
Number of Restricted Shares, Ending Balance | shares 100,836
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 $ 6.46
Weighted Average Grant Date Fair Value Per Share, Shares Vested | $ / shares 6.87
Weighted Average Grant Date Fair Value Per Share, Ending Balance | $ / shares $ 5.95