Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation and Cash-Based Incentive Compensation (Schedule of Stock Activity Related to Share-Based Compensation) (Detail)

v2.4.0.6
Share-Based Compensation and Cash-Based Incentive Compensation (Schedule of Stock Activity Related to Share-Based Compensation) (Detail) (USD $)
9 Months Ended
Sep. 30, 2012
Restricted Stock [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Weighted Average Grant Date Fair Value Per Share, Outstanding $ 15.81
Weighted Average Grant Date Fair Value Per Share, Granted $ 19.13
Weighted Average Grant Date Fair Value Per Share, Vested $ 13.59
Weighted Average Grant Date Fair Value Per Share, Outstanding $ 18.70
Shares, Outstanding 51,870
Shares, Granted 21,954
Shares, Vested (27,475)
Shares, Outstanding 46,349
Restricted Stock Units (RSUs) [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Weighted Average Grant Date Fair Value Per Share, Outstanding $ 14.67
Weighted Average Grant Date Fair Value Per Share, Granted $ 18.64
Weighted Average Grant Date Fair Value Per Share, Forfeited $ 21.59
Weighted Average Grant Date Fair Value Per Share, Outstanding $ 15.76
Shares, Outstanding 1,732,703
Shares, Granted 764,478
Shares, Forfeited (53,199)
Shares, Outstanding 2,443,982