Quarterly report pursuant to Section 13 or 15(d)

Summary of Restricted Stock Award Activity (Detail)

v3.7.0.1
Summary of Restricted Stock Award Activity (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Restricted Stock    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of restricted stock unit awards that vested during the period 137,992  
Fair value of restricted shares that vested during the period $ 6,013 $ 12,742
Compensation expense recognized during the period 2,127 2,901
Income tax benefit recognized upon vesting of share based awards $ 1,972 $ 4,748
Restricted Stock Units (RSUs)    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of restricted stock unit awards that vested during the period 97,115 143,872
Fair value of restricted shares that vested during the period $ 4,155 $ 4,747
Accumulated dividends paid upon vesting of restricted stock unit awards [1] 68 404
Compensation expense recognized during the period 1,114 2,217
Income tax benefit recognized upon vesting of share based awards $ 1,745 $ 1,993
[1] Additional dividends of approximately $244 were paid during April 2017 related to the restricted stock unit awards that vested during the three months ended March 31, 2017.