Quarterly report pursuant to Section 13 or 15(d)

Summary of Restricted Stock Activity (Detail)

v3.10.0.1
Summary of Restricted Stock Activity (Detail) - Restricted Stock
9 Months Ended
Sep. 30, 2018
$ / shares
shares
Shares of Restricted Stock  
Shares of Restricted Stock, Beginning balance | shares 650,581
Shares of Restricted Stock, Granted | shares 321,406
Shares of Restricted Stock, Vested | shares (242,945)
Shares of Restricted Stock, Forfeited | shares (20,925)
Shares of Restricted Stock, Ending balance | shares 708,117
Shares of Restricted Stock, Unvested restricted stock | shares 708,117
Weighted Average Grant Date Fair Value  
Weighted Average Grant Date Fair Value Outstanding, Beginning | $ / shares $ 35.81
Weighted Average Grant Date Fair Value, Granted | $ / shares 38.79
Weighted Average Grant Date Fair Value, Vested | $ / shares 31.16
Weighted Average Grant Date Fair Value, Forfeited | $ / shares 38.57
Weighted Average Grant Date Fair Value Outstanding, Ending | $ / shares 38.67
Weighted Average Grant Date Fair Value, Unvested restricted stock | $ / shares $ 38.67