v2.4.0.6
Share-Based Compensation (Summary of Restricted Stock and PSU Activity) (Details) (USD $)
3 Months Ended
Mar. 31, 2013
Restricted stock [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of Awards, Unvested balances 3,204,188
Number of Awards, Granted 114,290
Number of Awards, Vested (90,882)
Number of Awards, Forfeited (75,267)
Number of Awards, Unvested balances 3,152,329
Weighted-Average Grant Date Fair Value, Unvested balances $ 23.20
Weighted-Average Grant Date Fair Value, Granted $ 29.44
Weighted-Average Grant Date Fair Value, Vested $ 24.34
Weighted-Average Grant Date Fair Value, Forfeited $ 24.02
Weighted-Average Grant Date Fair Value, Unvested balances $ 23.38
PSUs [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of Awards, Unvested balances 1,879,799
Number of Awards, Granted 28,028
Number of Awards, Vested (88,998)
Number of Awards, Forfeited (36,562)
Number of Awards, Unvested balances 1,782,267
Weighted-Average Grant Date Fair Value, Unvested balances $ 23.14
Weighted-Average Grant Date Fair Value, Granted $ 23.44
Weighted-Average Grant Date Fair Value, Vested $ 19.75
Weighted-Average Grant Date Fair Value, Forfeited $ 23.08
Weighted-Average Grant Date Fair Value, Unvested balances $ 23.32