• Filing Date: 2018-03-07
  • Form Type: 10-K
  • Description: Annual report
v3.8.0.1
Stock Based Compensation - Information with Respect to Unvested Restricted Stock Awards Stock Option and Incentive Plan (Detail) - Restricted Stock [Member] - $ / shares
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Beginning balance, shares 542,503 620,513 639,705
Granted, Number of Restricted Stock Awards 154,936 142,440 83,260
Vested, Number of Restricted Stock Awards (75,983) (47,152) (59,695)
Cancelled, Number of Restricted Stock Awards   (160,000)  
Forfeited, Number of Restricted Stock Awards (23,766) (13,298) (42,757)
Ending balance, shares 597,690 542,503 620,513
Nonvested, Weighted-Average Grant Date Fair Value, Beginning balance $ 30.81 $ 30.33 $ 28.33
Granted, Weighted-Average Grant Date Fair Value 42.92 32.35 44.46
Vested, Weighted-Average Grant Date Fair Value 37.95 42.27 30.13
Cancelled, Weighted-Average Grant Date Fair Value   26.27  
Forfeited, Weighted-Average Grant Date Fair Value 36.32 39.06 28.15
Nonvested, Weighted-Average Grant Date Fair Value, Ending balance $ 32.82 $ 30.81 $ 30.33