Quarterly report pursuant to Section 13 or 15(d)

Treasury Stock and Share Based Awards - Additional Information (Detail)

v3.7.0.1
Treasury Stock and Share Based Awards - Additional Information (Detail)
$ / shares in Units, $ in Thousands
3 Months Ended
Mar. 31, 2017
USD ($)
$ / shares
shares
Restricted Stock  
Stockholders Equity Note [Line Items]  
Number of hypothetical shares of common stock 178,259
Market value of common stock on the dates of grant | $ / shares $ 42.37
Forfeiture rate for restricted stock awards 10.00%
Award vesting period for restricted stock granted 4 years
Restricted Stock Units (RSUs)  
Stockholders Equity Note [Line Items]  
Number of hypothetical shares of common stock 175,634
Market value of common stock on the dates of grant | $ / shares $ 42.37
Unrecognized compensation expense | $ $ 10,390
Remaining Compensation Expense recognition period (in years) 2 years
Percentage of IRR, which is the threshold 7.00%
Percentage of IRR, which is the target 9.50%
Percentage of IRR, which is the maximum 13.00%
Percentage of restricted stock units vest 100.00%
Percentage of IRR expected 11.00%
Expected forfeiture rate 5.00%
Number of hypothetical shares of common stock at assumed IRR level 628,189
Actual cumulative forfeitures (in units) 7,407
Unvested Restricted Stock Awards  
Stockholders Equity Note [Line Items]  
Unrecognized compensation expense | $ $ 17,179
Remaining Compensation Expense recognition period (in years) 3 years