Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation and Employee Benefit Plans (Details 2)

v2.4.0.6
Share-Based Compensation and Employee Benefit Plans (Details 2) (USD $)
 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2008
Stock Options        
Exercised (in shares) (191,264) (278,656) (464,601)  
Options
        
Stock Options        
Outstanding at the beginning of the period (in shares) 1,188,284 1,501,906 1,949,319  
Granted (in shares)     50,000  
Forfeited/Expired (in shares) (51,598) (34,966) (32,812)  
Exercised (in shares) (191,264) (276,656) (464,601)  
Outstanding at the end of the period (in shares) 945,422 1,188,284 1,501,906  
Exercisable at the end of the period (in shares) 945,422 1,188,284 1,389,141  
Weighted Average Exercise Price per Share        
Outstanding at the beginning of the period (in dollars per share) $ 33.07 $ 30.29 $ 25.96  
Granted (in dollars per share)     $ 31.51  
Forfeited/Expired (in dollars per share) $ 42.82 $ 46.59 $ 44.33  
Exercised (in dollars per share) $ 12.82 $ 16.42 $ 11.25  
Outstanding at the end of the period (in dollars per share) $ 36.63 $ 33.07 $ 30.29  
Exercisable at the end of the period (in dollars per share) $ 36.63 $ 33.07 $ 29.42  
Weighted Average Remaining Contractual Term        
Outstanding at the beginning of the period (in years) 5 5 5  
Outstanding at the end of the period (in years) 4 5 5  
Aggregate Intrinsic Value        
Outstanding at the beginning of the period $ 7,987,000 $ 14,579,000 $ 18,744,000  
Outstanding at the end of the period 510,000 7,987,000 14,579,000  
Aggregate intrinsic value of options exercised $ 4,000,000 $ 5,900,000 $ 10,400,000  
Minimum | Options
        
Stock Options, Exercise Price Range        
Exercise price range, options outstanding, low end of range (in dollars per share) $ 13.40 $ 9.54 $ 8.63 $ 7.38
Exercise price range, options granted (in dollars per share)     $ 29.98  
Exercise price range, options forfeited (in dollars per share) $ 22.49 $ 41.33 $ 25.52  
Exercise price range, options exercised (in dollars per share) $ 9.54 $ 8.63 $ 7.38  
Maximum | Options
        
Stock Options, Exercise Price Range        
Exercise price range, options outstanding, high end of range (in dollars per share) $ 57.00 $ 57.00 $ 57.00 $ 57.00
Exercise price range, options granted (in dollars per share)     $ 37.61  
Exercise price range, options forfeited (in dollars per share) $ 50.59 $ 49.60 $ 53.16  
Exercise price range, options exercised (in dollars per share) $ 30.25 $ 42.07 $ 35.87  
Range of Exercise Price One | Options | Vested
        
Stock Options        
Exercisable at the end of the period (in shares) 53,957 231,946 83,441  
Stock Options, Exercise Price Range        
Exercise price range, options outstanding, low end of range (in dollars per share) $ 13.40 $ 9.54 $ 8.63  
Exercise price range, options outstanding, high end of range (in dollars per share) $ 16.73 $ 16.73 $ 10.99  
Range of Exercise Price Two | Options | Vested
        
Stock Options        
Exercisable at the end of the period (in shares) 225,903 246,103 345,792  
Stock Options, Exercise Price Range        
Exercise price range, options outstanding, low end of range (in dollars per share) $ 16.74 $ 16.74 $ 11.00  
Exercise price range, options outstanding, high end of range (in dollars per share) $ 30.04 $ 30.04 $ 16.99  
Range of Exercise Price Three | Options | Vested
        
Stock Options        
Exercisable at the end of the period (in shares) 198,762 205,012 172,914  
Stock Options, Exercise Price Range        
Exercise price range, options outstanding, low end of range (in dollars per share) $ 30.05 $ 30.05 $ 17.00  
Exercise price range, options outstanding, high end of range (in dollars per share) $ 41.28 $ 41.28 $ 25.99  
Range of Exercise Price Four | Options | Vested
        
Stock Options        
Exercisable at the end of the period (in shares) 466,800 253,607 190,287  
Stock Options, Exercise Price Range        
Exercise price range, options outstanding, low end of range (in dollars per share) $ 41.29 $ 41.29 $ 26.00  
Exercise price range, options outstanding, high end of range (in dollars per share) $ 57.00 $ 45.24 $ 34.99  
Range of Exercise Price Five | Options | Vested
        
Stock Options        
Exercisable at the end of the period (in shares)   251,616 343,040  
Stock Options, Exercise Price Range        
Exercise price range, options outstanding, low end of range (in dollars per share)   $ 45.25 $ 35.00  
Exercise price range, options outstanding, high end of range (in dollars per share)   $ 57.00 $ 43.99  
Range of Exercise Price Six | Options | Vested
        
Stock Options        
Exercisable at the end of the period (in shares)     253,667  
Stock Options, Exercise Price Range        
Exercise price range, options outstanding, low end of range (in dollars per share)     $ 44.00  
Exercise price range, options outstanding, high end of range (in dollars per share)     $ 57.00