Quarterly report pursuant to Section 13 or 15(d)

Summary of Compensation Expense under Share-Based Payment Arrangements and Related Tax Benefit (Detail)

v2.4.0.8
Summary of Compensation Expense under Share-Based Payment Arrangements and Related Tax Benefit (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Share-based compensation $ 2,695 $ 3,159 $ 4,950 $ 5,818
Tax benefit computed at the statutory rate 943 1,106 1,733 2,036
Restricted Stock
       
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Share-based compensation 99 108 198 214
Restricted Stock Units (RSUs)
       
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Share-based compensation $ 2,596 $ 3,051 $ 4,752 $ 5,604